GBT Azimuth / Elevation Servo System Site Acceptance Test Procedures

Project: PTCS Servo

Dry Run Tests - This is not the Test procedure

Comments and Questions:

  • This document is structured after the original GBT Servo Site Test Procedures document. In particular Chapter 5 is for functional Azimuth / Elevation tests. Chapter 6, which is omitted, is for Feed Arm Servo tests. Chapter 7 is for Auto Stow. And chapter 8 was added to test internal servo system fault conditions which were never tested before and / or which are new to the design.

  • The original Servo Site Acceptance Test Procedures were written:
    1. To prove the antenna was wired correctly.
    2. To verify hardware conforms to the design specifications.
    3. Rigorous enough for the end customer to be able to reproduce in the future.
    4. To test all system requirements.

  • In our testing we already know the antenna is wired correctly, we will not be testing the wiring on the antenna. But since we are deploying a redesigned PLC system, with SRP updated logic, all system discretes will need to be fully tested.

  • The motors and drives were tested to verify they could produce the specified torque and rates. Brakes were tested to verify they could hold worst case motor / drive failures. These type tests do not need to be reproduced for the PTCS SRP upgrade.

  • Some of the test specifics will be modified to allow us to test the system to our needs. An example would be testing the UPS. In section 5.1 the original procedure required us to track a source, disconnect the power to the UPS, then verify there were no jumps in the position data. This is not a scenario we would ever imagine. If we are on UPS then we have lost site power, are holding up the computers and LANs and waiting for the generator to start so we can auto-stow. The key issue we are concerned about is that the UPS holds up the critical subsystems until the generator comes on-line.

  • Some of the procedures will be stream-lined, listing the functions we wish to test but not listing every painstaking action needed to be taken. It is assumed the tests are being performed by a member of the servo group and is knowledgeable in the area he/she is testing.

  • Since the PTCS SRP upgrade is supposed to be implementing the same functional requirements that the current / original system supports then there should not be many new functional requirement tests generated to test the new SRP upgraded system.

  • The original Servo Site Acceptance Test Procedure did not focus on what would happen in the event of various internal servo failures. The failures they tested were primarily antenna failures that the servo system was designed to catch, IE: E-Stops, limits, over-temperatures, brake fault etc. Internal servo subsystem tests are necessary to verify the new, and much more complex, servo system will fail safe when inter-subsystem and intra-subsystem failures occur. They should also verify simple failures, like a LAN link down, are typically easy to recover from. They should not, normally, require the full system to be rebooted and when they do then system reboots should not require highly technical procedures to be followed.

1. SCOPE

This procedure details the tests, measurements and performance criteria for a Site Acceptance Test of the Green Bank Telescope Antenna Control System.

1.1 EQUIPMENT CONFIGURATION

1.2 TEST CONDITIONS

All tests will be performed under ambient conditions of temperature, atmospheric pressure and humidity. All heating and air conditioning equipment intended to provide a controlled environment must be installed and operating.

1.3 TEST DATA

This document provides for the recording of test data. Test steps followed by the word "Record" require a measurable value to be recorded in the space provided. Test steps followed by the word "Check" require a Check Mark to be made in the space provided upon successful completion of the observation or function.

Any additional data generated during the performance of this test (recordings, notes, calculations, etc.) are considered to be part of this test procedure and shall be attached hereto.

1.4 ACCEPTANCE/REJECT CRITERIA

Most individual test measurements have tolerance limits specified in this procedure. The basis for acceptance of the equipment is:

  • All measurements are within the tolerance allowed.
  • All test functions or observations are successfully completed.

1.5 ACRONYMS

The following Acronyms may appear in this procedure.

  • AZ - Azimuth
  • ACU - Antenna Control Unit (Usually referred to M&C in this document.)
  • CCU - Central Control Unit
  • CCW - Counter Clockwise
  • CW - Clockwise
  • EL - Elevation
  • HVIC - High Voltage Interlock Cabinet
  • M&C - Monitor and Control
  • MRU - Manual Rate Unit
  • MSU - Manual Stow Unit
  • OCT - Operation Control Terminal - Note: It has been decided there will not be an OCT per se, but rather a remote control room display of the OCU screen using VNC.
  • OCU - Operations Control Unit
  • PDU - Power Drive Unit
  • PEI - Position Encoder Interface Unit
  • PMU - Portable Maintenance Unit
  • UPS - Uninterruptable Power Supply
  • VNC - Virtual Network Computing. A mechanism used for local control of remotely located computers. This software is in wide use at the observatory, and used in a similar manner to 'remote' other OCU units on site.

  • Please note that there are multiple CCUs, OCUs, and OCTs referred to in this system. The original units and the SRP upgrade units. When referring to the azimuth and elevation axes the user must assume the configuration defines which unit is being referred to. When referring to the secondary axis servo system the OCU and OCT always refer to the original configuration and units, never the SRP upgrade units.

2. APPLICABLE DOCUMENTS

2.1 The following documents form a part of this Test Procedure to the extent specified herein.

2.2 The following specifications are verified during the execution of this test procedure.

AZ/EL PARAMETERS SPEC VALUE
AZ Velocity 0.66 Deg/s
EL Velocity 0.33 Deg/s
AZ Acceleration 0.1 Deg/s2
EL Acceleration 0.1 Deg/s2
EL Tracking Accuracy 1 arcsec
AZ Tracking Accuracy 1 arcsec
AZ Travel Range -90 Deg - + 450 Deg
EL Travel Range 5 Deg - 95 Deg
CW Software Limit 90.2 Deg
CCW Software Limit 269.8 Deg
UP Software Limit 95.1 Deg
DN Software Limit 4.9 Deg
CW Prelimit 450.7 Deg
CCW Prelimit -90.7 Deg
UP Prelimit 95.35 Deg
DN Prelimit 4.65 Deg
CW Redundant Prelimit 451.2 Deg
CCW Redundant Prelimit -91.2 Deg
UP Redundant Prelimit 95.6 Deg
DN Redundant Prelimit 4.4 Deg
CW Final Limit 451.7 Deg
CCW Final Limit -91.7 Deg
UP Final Limit 95.85 Deg
DN Final Limit 4.15 Deg
CW Redundant Final Limit 452.2 Deg
CCW Redundant Final Limit -92.2 Deg
UP Redundant Final Limit 96.1 Deg
DN Redundant Final Limit 3.9 Deg

3. Equipment

3.1 Test Equipment

The following items are required to perform these tests:
  • Digital Voltmeter
  • Digital Ammeter
  • Low frequency network analyzer
  • Oscilloscope

3.2 Equipment Under Test

Equipment Part Number Serial Number
OCU PC    
OCT PC    
CCU PC    
Az PEI    
Az MCI #1    
Az MCI #2    
Az MCI #3    
Az MCI #4    
Az MCI #5    
Az MCI #6    
Az MCI #7    
Az MCI #8    
Az MCI #9    
Az MCI #10    
Az MCI #11    
Az MCI #12    
Az MCI #13    
Az MCI #14    
Az MCI #15    
Az MCI #16    
El PEI    
El MCI #1    
El MCI #2    
El MCI #3    
El MCI #4    
El MCI #5    
El MCI #6    

4. Equipment Measurement and Verification

These tests verify the system is ready for testing.

4.1 AC Voltage Test and Measurement

Verify that the equipment is configured per the system schematic. Using a DVM, measure the input power at the respective units to verify proper voltage and frequency.

  • Power Drive Units: 480 VAC +/- 5%, 60 Hz

  • PDU #1 ______________(Record)

  • PDU #2 ______________(Record)

  • PDU #3 ______________(Record)

  • PDU #4 ______________(Record)

  • Power Drive Units: 48 VAC +/- 5%, 60 Hz

  • PDU #1 ______________(Record)

  • PDU #2 ______________(Record)

  • PDU #3 ______________(Record)

  • PDU #4 ______________(Record)

  • Interface Cabinet, 3 Phase 208 VAC +/- 5%, 60 Hz ______________(Record)
    • Verify each leg of the 3 phase 208 Volt input is within +/- 5%.
    • _______(Check)

  • Interface Cabinet, 120 VAC +/- 5%, 60 Hz ______________(Record)

  • Computer Rack
    • Verify each leg of the 3 phase 208 Volt input is within +/- 5%.
    • _______(Check)
    • Verify each leg of the 3 phase 208 Volt UPS output is within +/- 5%.
    • _______(Check)

4.2 DC Voltage Test and Measurement

4.2.1 Verify the Interface Cabinet Voltages are within 5% of their rated values.

  • Using a DVM, measure the Interface Cabinet power supply voltages. Record the values below.

  • PLC +5V +/- 5% ______________(Record)
  • Verify this reading matches the voltage the PLC is reading at V3006 (real number).
    • _______(Check)

  • PLC +15V +/- 5%______________(Record)
  • Verify this reading matches the voltage the PLC is reading at V3010 (real number).
    • _______(Check)

  • PLC -15V +/- 5%______________(Record)
  • Verify this reading matches the voltage the PLC is reading at V3012 (real number).
    • _______(Check)

  • Rate-Loop Board +5V +/- 5% ______________(Record and Check)

  • Rate-Loop Board +15V +/- 5%______________(Record and Check)

  • Rate-Loop Board -15V +/- 5%______________(Record and Check)

  • +24V Supply (External Switches) ______________(Record)
  • Verify this reading matches the voltage the PLC is reading at V3014 (real number).
    • _______(Check)

  • +24V Supply (Brake Relays) ______________(Record)

4.2.2 Verify the computer rack voltages.

  • Verify the + 5 and + 3.3 volt power supplies for the azimuth and elevation PEIs are within +/- 5%
  • _______(Check)
  • Verify the +24 volt DC suppy for the N-Tron media converter is 24 volts +/- 5%.
  • _______(Check)

4.2.3 Verify the MCI voltages.

  • Verify all MCI supplies in PDU #1
    • + 24 Volts +/- 5% ______________(Record)
  • Verify all MCI supplies in PDU #2
    • + 24 Volts +/- 5% ______________(Record)
  • Verify all MCI supplies in PDU #3
    • + 24 Volts +/- 5% ______________(Record)
  • Verify all MCI supplies in PDU #4
    • + 24 Volts +/- 5% ______________(Record)

4.2.4 Verify the PEI voltages.

  • Verify Azimuth PEI +5 Volts +/- 5% ______________(Record)
  • Verify Azimuth PEI +3.3 Volts +/- 5% ______________(Record)
  • Verify Elevation PEI +5 Volts +/- 5% ______________(Record)
  • Verify Elevation PEI +3.3 Volts +/- 5% ______________(Record)

4.3 IRIG-B

*Verify IRIG-B Timing Reference is available to the CCU and the time displayed on M&C computers match that of the time code generator.
  • _______(Check) *Verify the IRIG-B is operational by using the command "ntpq -p" command on the CCU. This command displays the status and offset from ntp site time.
  • _______(Check)
  • Using an oscilloscope record
  • Using an oscilloscope record
    1. The Carrier P-P voltage ______________(Record)
    2. The Signal P-P voltage ______________(Record)
    3. Verify the Carrier - Signal P-P voltage is greater than or equal to 3.
    • _______(Check)

4.4 OCU / OCT CLOCKS

MS Window systems, at NRAO Green Bank, typically get their time through \AD\gbdca. Neither the OCU or the OCT have access to the site LAN and therefore will not have access to the NTP server on \AD\gbdca. Therefore the OCU and OCT computers will be directed to receive their time from the NTP server on the CCU.

Visually verify the OCU and OCT clocks match the CCU IRIG-B time to the second.
  • _______(Check)

4.5 ETHERNET LANS

Verify the various Ethernet LANS are up and stable.
  • CCU - PLC Modbus ___ (Check)
  • CCU - M&C ___ (Check)
  • OCU - OCT Ethernet Link ___ (Check)
  • OCU - PLC Ethernet Link ___ (Check)
  • OCU - CCU (for Clock) ___ (Check)

Verify the PEI links are up and stable by checking CCU program output (error messages will be present if links are not up).
  • CCU - Azimuth PEI serial link. ___ (Check)
  • CCU - Elevation PEI serial link. ___ (Check)

5. AZIMUTH AND ELEVATION SERVO SYSTEM FUNCTIONAL TESTS

This section verifies the functional system requirements for proper operation of the Azimuth and Elevation axes.

5.A Verify Original and Upgraded Servo System Basic Functionality.

This section verifies we can operate the GBT with either the original or the upgraded servo system with minimal effort.

5.A.1 GBT Configured with Original Servo Hardware and Software.

  • Configure the system to be run by the original servo system.
  1. Verify or download PLC logic from: /home/gbt/subsys/servo/1-1-LatestExecutables/GBT/PLC/Current-PLC-Logic/gbtAzEl-PRE-SRP using DirectSoft5.
  2. Disconnect the (new) CCU servo LAN (fiber and CAT5) from the media converter with the PLC in the Servo Interface Cabinet.
  3. Connect the (old) oCCU servo LAN fiber to the media converter with the PLC in the Servo Interface Cabinet.
  4. Reboot the PLC
  5. Reboot the oCCU
  6. On each of the 3 Rate Loop Boards there are 2 switches with PCD and NRAO positions, place each switch in the PCD position.
  7. There are 6 black switch boxes in the NRAO Servo Rack which switch the Servo Monitor and Az/El encoders to / from the old/new systems. Place all 6 switches in the "A" position.
  8. For RFI purposes, unplug the power for the Az/El encoder FPGA boxes (in the PCD Servo Rack).
  9. Verify the oOCU displays the correct current positions for the GBT Az/El axes.
  10. Move azimuth and elevation to mid travel ranges and disable both axes.

5.A.2 GBT Configured with Upgraded Servo Hardware and Software.

  • Configure the system to be run by the upgraded servo system as follows:
  1. Verify all axes are disabled.
  2. There are 6 black switch boxes in the NRAO Servo Rack which switch the Servo Monitor and Az/El encoders to / from the old/new systems. Place all 6 switches in the "B" position.
  3. On each of the 3 Rate Loop Boards there are 2 switches with PCD and NRAO positions, place each switch in the NRAO position.
  4. Plug in the power for the Az/El encoder FPGA boxes (in the PCD Servo Rack).
  5. Disconnect the (old) oCCU servo LAN fiber from the media converter with the PLC in the Servo Interface Cabinet.
  6. Connect the (new) CCU servo LAN (fiber and CAT5) to the media converter with the PLC in the Servo Interface Cabinet.
  7. Verify that the cable going to the Azimuth Rate Loop Board #1 and Elevation Rate Loop Board CJ2 are plugged in.
  8. Download the proper PLC logic into the PLC using DirectSoft5.
  9. Reboot the PLC
  10. Reboot the CCU (restart CCU software)
  11. Start up the OCU.

  • Verify the GBT can be safely controlled by performing the following Servo Site Acceptance Test Procedures, from this document:
  1. Section 5.4.1 Faults and Statuses with the axes manually (PMU or MRU) enabled and rates set to zero testing the E-Stops only.
    • _______(Check)
  2. Section 5.2 Manual Rate Units
    • _______(Check)
  3. Section 5.5.4 Computer Servo Enabling
    • _______(Check)
  4. Section 5.5.5 Computer Servo Moving
    • _______(Check)

5.1 Uninterruptible Power Supply Test

This test will verify the operation of the UPS.
  • Disconnect the input power to the UPS and allow it to power the Interface Cabinet, CCU Rack, and all 4 PDUs.
  • Monitor the system and insure the UPS continues to power all systems properly for 30 minutes.
  • Re-apply power to the UPS.
  • Verify you can move the stow pin, enable and move both axes without any faults. _______(Check)

5.2 MANUAL RATE UNIT/PORTABLE MAINTENANCE UNIT

The Manual Rate Unit (MRU) and the Portable Maintenance Unit (PMU) function identically. They may be enabled through the Control screen on the OCU or OCT and are also enabled when the CCU is not powered.

5.2.1 MRU / PMU Control With Loss of Ethernet / CCU.

  • Plug the PMU into the Interface Cabinet then verify that the POWER LED is illuminated on the MRU and PMU.
  • _______(Check)
  • Verify status messages "MRU AVAILABLE" and "PMU AVAILABLE" are present.
  • _______(Check)
  • Disconnect the Ethernet link to the CCU and verify you can take control of the azimuth and elevation axes with both the MRU and PMU.
  • _______(Check)
  • Verify you can extend and retract the elevation stow pin with the MSU.
  • _______(Check)
  • Reconnect the Ethernet link to the CCU.
  • _______(Check)

5.2.2 Manual Rate Unit

  1. Select MRU from the OCU Control window. Verify that the ENABLE LED is illuminated on the MRU and the ENABLE LED on the PMU is out. Verify the OCU Control window indicates "Unit In Control of Az/El Axes" is MRU.
    • _______(Check)
  2. Take control with the MRU by pressing the ACTIVE button and verify the ENABLED LED is lit and status message "MRU IN AZ/EL CONTROL" appears at the OCU.
    • _______(Check)
  3. Select the LO rate. Verify that the LO LED is illuminated and AZ and EL do not display a fault condition.
    • _______(Check)
  4. Enable each axis by depressing the axis ENABLE button at the MRU and measure the bi-directional full speed of the axes, while in low rate mode.
    • AZ CW Deg/Min ______________(Record)
    • AZ CCW Deg/Min ______________(Record)
    • EL UP Deg/Min ______________(Record)
    • EL DN Deg/Min ______________(Record)
  5. Verify the full speed is greater than or equal to the desired speed for each axis.
    • AZ +/- 4 Deg/Min _______(Check)
    • EL +/- 2 Deg/Min _______(Check)
  6. While moving at zero rate, create an axis fault and verify the FAULT LED is lit and the axis is disabled.
    • AZ _______(Check)
    • EL _______(Check)
  7. Clear the fault. Select the HI rate and verify the HI LED is lit.
    • _______(Check)
  8. Enable each axis and measure the bi-directional full speed (Hi Rate) of the axes.
    • (DO NOT RUN THIS SECTION FOR INITIAL CHECKOUT.)
    • AZ CW Deg/Min ______________(Record)
    • AZ CCW Deg/Min ______________(Record)
    • EL UP Deg/Min ______________(Record)
    • EL DN Deg/Min ______________(Record)
  9. Verify the full speed is as follows:
    • AZ +/- 40 Deg/Min _______(Check)
    • EL +/- 20 Deg/Min _______(Check)
  10. Select the AZ/EL Position Designate, AZ Preset Position and El Stow windows, on the OCU, and verify that the OCU will not allow the user to enter any commands on this window.
    • ____DONE___(Check)
  11. Attempt to enable the PMU and verify it will not enable while the MRU is Active.
    • __PICK_____(Check)
  12. Attempt to take control of the CCU with the OCU/OCT and verify you cannot.
    • ___DONE____(Check)
  13. Attempt to take control of the CCU with the M&C computer and verify you cannot.
    • ___DONE____(Check)
  14. Disable the MRU and verify the ACTIVE LED is off, and the "MRU IN AZ/EL CONTROL" status message at the OCU clears.
The wording doesn't match the message: MRU IN ACTIVE CONTROL
    • _______(Check)

5.2.3 Portable Maintenance Unit

  1. Select PMU from the OCU Control window. Verify that the ENABLE LED is illuminated on the PMU and the ENABLE LED on the MRU is out. Verify the OCU Control window indicates "Unit In Control of Az/El Axes" is PMU.
    • _______(Check)
  2. Depress the Active button at the Portable Maintenance Unit (PMU) verify the ACTIVE LED is lit and the status message "PMU IN AZ/EL CONTROL" appears at the OCU.
The wording doesn't match the message: PMU IN ACTIVE CONTROL
    • ___DONE____(Check)
  1. Repeat Sections 5.2.2.3 through 5.2.2.9 and record results below.
    • LO Rate _______(Check)
    • AZ CW Deg/Min ______________(Record)
    • AZ CCW Deg/Min ______________(Record)
    • EL UP Deg/Min ______________(Record)
    • EL DN Deg/Min ______________(Record)
    • AZ +/- 4 Deg/Min _______(Check)
    • EL +/- 2 Deg/Min _______(Check)
    • EL _______(Check)
    • (DO NOT RUN THIS SECTION FOR INITIAL CHECKOUT.)
    • HI Rate _______(Check)
    • AZ CW Deg/Min ______________(Record)
    • AZ CCW Deg/Min ______________(Record)
    • EL UP Deg/Min ______________(Record)
    • EL DN Deg/Min ______________(Record)
    • AZ +/- 40 Deg/Min _______(Check)
    • EL +/- 20 Deg/Min _______(Check)
    • Axis Fault Az _______(Check)
    • Axis Fault EL _______(Check)
  2. Plug the PMU into each available AZ/EL junction box and verify all functions of the PMU. (THESE TESTS ARE NOT REQUIRED SINCE THE WIRING HAS BEEN TESTED AND OPERATIONAL FOR OVER 11 YEARS.)
    • EL Drive Area _______(Check)
    • AZ Truck #1 _______(Check)
    • AZ Truck #2 _______(Check)
    • AZ Truck #3 _______(Check)
    • AZ Truck #4 _______(Check)
  3. Activate an axis fault for each axis and verify the FAULT LED lights and the axis disables.
    • _______(Check)
  4. Select the AZ/EL Position Designate, AZ Preset Position and El Stow windows, on the OCU, and verify that the OCU will not allow the user to enter any commands on this window.
    • _______(Check)
  5. Attempt to enable the MRU and verify it will not enable while the PMU is Active.
    • _______(Check)
  6. Attempt to take control with the OCU/OCT and verify you cannot.
    • _______(Check)
  7. Attempt to take control with the M&C computer and verify you cannot.
    • _______(Check)

5.3 POWER OFF CONTROL/POWER UP SELF TEST

5.3.1 OCU / M&C Power Off Control

  1. Verify you can take control with the PMU.
    • _______(Check)
  2. Power off the CCU and verify the PMU remains enabled and has complete control capabilities.
    • _______(Check)
  3. Disable the PMU and verify the ACTIVE LED is off and the ENABLED LED at the MRU is lit.
    • _______(Check)
  4. Activate the MRU. Verify that the ENABLED LED at the PMU is off and control is available at the MRU.
    • _______(Check)
  5. Power up the CCU and verify the MRU remains in control.
    • ___DONE____(Check)
  6. Disable the MRU and verify that the horn honks as AZ/EL control is transferred from the MRU to the CCU.
    • ___DONE____(Check)
  7. Take control with the OCU and issue a position designate command for both axes at 1 deg/min each.
    • _______(Check)
  8. Before the system reaches the required position, disconnect the OCU-CCU data link. Verify the proper fault messages occur on both the OCU and the M&C systems and the system executes a servoed soft stop.
    • ___DONE____(Check)
  9. Reconnect the OCU-CCU data link. Verify you can take control with the OCU or OCT.
    • __DONE_____(Check)
  10. Release control with the OCU/OCT then take control with the M&C and issue a move command.
    • ___DONE____(Check)
  11. Disconnect the OCU-CCU data link. Verify the proper fault messages occur on both the OCU and M&C systems but the system continues responding to the M&C commands.
    • ___DONE____(Check)
  12. Reconnect the OCU-CCU data link.
    • __DONE_____(Check)
13 Repeat steps 1-11 replacing OCU/OCT with M&C and M&C with OCU/OCT then retest. Some of the messages will be different, verify the proper unit retains control and servoed soft stops occur properly. No MLINK down message on OCU?

5.3.2 CCU Power Off Control

  1. Power off the CCU and verify that the ENABLE LED at both the MRU and PMU are illuminated and control is available at either unit.
    • _______(Check)
  2. Activate the PMU. Verify that the ACTIVE LED is on and control is available at the PMU. Verify that the ENABLED LED at the MRU is off.
    • _______(Check)
  3. Disable the PMU and verify the ACTIVE LED is off and the ENABLED LED at the MRU is lit.
    • _______(Check)
  4. Activate the MRU. Verify that the ACTIVE LED is on and control is available at the MRU. Verify that the ENABLED LED at the PMU is off.
    • _______(Check)
  5. Power up the CCU and verify that the MRU remains in control.
    • __DONE_____(Check)
  6. Disable the MRU and take control with the OCU.
    • ___DONE____(Check)

5.3.3 Power Up Control

  1. Power off the CCU, M&C, and OCU then verify that the ENABLE LED at both the MRU and PMU are illuminated and either unit can take control and enable the axes.
    • _______(Check)
  2. Power up the full system (CCU, M&C, OCT and OCU).
    • ___DONE____(Check)
  3. Take control of the CCU with the M&C computer.
    • Verify the Operator can take control and move both azimuth and elevation axes and insert / retract the stow pin.
    • ___DONE____(Check)
  4. Take control of the CCU with the OCU.
    • Verify the Operator can take control and move both azimuth and elevation axes and insert / retract the stow pin.
    • __DONE_____(Check)

5.3.4 Watchdog Tests

5.3.4.1 CCU Watchdog Bits

The PLC monitors two digital lines which are driven and toggled by the CCU. These watchdogs are intended to verify end-to-end loop closure is being met within a specified tolerance. These watchdogs replace the network watchdog bit which was at C301 of the PLC.

  • Enable both axes through the OCU and servo at zero rate.
  • Stop the CCU, to stop the periodic toggling of the hardware bits.
  • Verify the PLC disables both axes and sets the brakes within 2 seconds.
  • ___ (Check)
  • Verify the OCU properly responded to these two axis disables by changing the "MOVE AZ" and "MOVE EL" buttons to "ENABLE".
  • _______(Check)
  • Enable both axes through M&C and servo at zero rate.
  • Stop the CCU, to stop the periodic toggling of the hardware bits.
  • Verify the PLC disables both axes and sets the brakes within 2 seconds.
  • ___ (Check)
  • Verify M&C properly responded to these two axis disables on the control screens and the message screens.
If the CCU software is not running, the OCT & M&C displays will not contain the correct information.
  • _______(Check)

I couldn't test this in the lab

5.3.4.2 CCU Deadman Counter

The PLC checks to see that word location V3000 changes at least once every 2 seconds. This verifies the Ethernet link between the CCU and PLC is operating.

  • Enable both axes through the OCU and servo at zero rate.
  • Stop the CCU from incrementing this location by disabling the function it is monitoring.
  • Verify the PLC performs a brake sequenced soft stop for both axes within 2 seconds.
  • ___ (Check)
  • Verify the OCU properly responded to these two axis disables by changing the "MOVE AZ" and "MOVE EL" buttons to "ENABLE".
  • _______(Check)
  • Enable both axes through M&C and servo at zero rate.
  • Stop the CCU from incrementing this location by disabling the function it is monitoring.
  • Verify the PLC performs a brake sequenced soft stop for both axes within 2 seconds.
  • ___ (Check)
  • Verify M&C properly responded to these two axis disables on the control screens and the message screens.
  • _______(Check)

I couldn't test this in the lab

5.3.4.3 OCU Deadman Counter

  • Take control of the system with either the OCU or OCT.
  • Enable azimuth and elevation axes and servo at zero rate.
  • Cause the OCU Deadman counter to stop counting.
  • Verify the CCU forces a computer servoed softstop.
  • _DONE__ (Check)
  • Verify the OCU is no longer in control of the CCU by taking control of the CCU with the M&C computer.
  • DONE___ (Check)

5.3.4.4 M&C Deadman Counter

  • Take control of the system with the M&C computer.
  • Enable azimuth and elevation axes and servo at zero rate.
  • Cause the M&C Deadman / Watchdog mechanism on the M&C computer to (i.e. stop the ACU software)
  • Verify the CCU forces a computer servoed softstop.
  • _DONE__ (Check)

5.3.5 Built in Test

    • The original CCU had various I/O cards in its chassis that could be tested on power-up. The new CCU communicates with the PLC and PEI cards over Ethernet and serial links respectively. These cards perform the majority of that I/O. Joe and Melinda should comment here on any built in test functionality they provide on power-up in the CCU.

5.3.5.1 CCU Built-In Tests

5.3.5.1.1 CCU Analog I/O Cards Configured
A check is performed to verify the analog/digital National Instruments card is present, and that it can be configured properly. If the driver or card(s) are not present, an error is printed and the CCU program will refuse to run. To test perform the following steps:
  1. With the CCU process not running, force the 'nirlpk' module to unload using the command 'modprobe -r nirlpk'.
  2. Start the CCU process. It should print an error concerning the driver/cards and exit. _DONE__ (Check)

A check is performed to verify the real-time serial driver is loaded, and that the interface can be configured. If the serial driver is not present, an error message is printed and the CCU program will exit.
  1. With the CCU process not running, unload the serial driver using the command 'modprobe -r xeno_16550A'.
  2. Start the CCU process. It should print an error concerning the driver and exit. _DONE__ (Check)
  3. Restore the driver with the command 'modprobe xeno_16550A'

5.3.5.1.3 CCU Validate Status Definition File Checksum
A check is performed on the MD5 checksum of the status definition file (statusDef.conf) to verify it matches the checksum in the main configuration file. This prevents accidental edits or modification to the file. To test this:
  1. Make a backup copy of the original statusDef.conf file.
  2. Edit the statusDef.conf file and change a few characters (anywhere), and save the file to disk.
  3. Restart/run the CCU process. It should detect the modification, print an error and exit. _DONE__ (Check)
  4. Restore the original file.

5.3.5.1.4 CCU to PLC Host Access
A check is performed to verify the PLC is accessible. If not the CCU program will exit with an error message. To test:
  1. Stop the CCU process.
  2. Turn the PLC off.
  3. Start the CCU process. It should print an error about not being able to communicate with the PLC and exit. _DONE__ (Check)
  4. Restore power to the PLC.

5.3.5.1.5 CCU Process Check
A check is performed to verify that a CCU process is not already running on the CCU host. If it detects a another CCU process, the 2nd process will print an error message and exit. To test:
  1. Start the CCU process.
  2. Attempt to start a 2nd CCU process.
  3. Verify the program prints an error about a CCU process already running and exits. _DONE__ (Check)

5.4.5.1.6 CCU IRIG Card Check
A check is performed to verify the CCU Bancomm BC635 IRIG card is present. If not the program should exit. To test:
  1. Stop the CCU process.
  2. Force the IRIG driver to unload using the command 'modprobe -r bc635pci_rtdm'
  3. Start the CCU process. Verify that an error message is printed and that the CCU process exits. _DONE__ (Check)
  4. Restore the IRIG driver with the command 'modprobe bc635pci_rtdm'.

5.3.5.2 PLC Built-In Test

The Automation Direct DL260 does continual testing of the processor and its various components. There are no user written power-up tests.
    • Force the PLC to perform a fault and disable the system while Azimuth and Elevation are enabled and servoing at zero rate by deleting the "end" rung and updating the code.
    • Verify all drives are disabled and all brakes are set.
    • ___ (Check)

5.4 FAULTS AND STATUS

Fault and status messages are displayed at the OCU, OCT, and the M&C Computer.

On the OCU/OCT Fault messages will flash, in the Faults window, until they are acknowledged. Faults are acknowledged by pressing the acknowledge button on the Faults window. Active statuses are indicated in an "active" font and revert to an "inactive" font after they become in-active. All Faults are recorded in a file named "AlarmLog" when they occur and when they clear. All Statuses are recorded in a file named "WarningLog" when they occur.

Fault and Status messages are also displayed on the CLEO Message window. Messages are displayed in different colors, referring to the different message levels. Each message is displayed with the time it became active or inactive.

5.4.1 Latching Faults Example

  1. Place the OCU or OCT in control and perform the following tests.
  2. With both axes enabled, activate any system fault condition (OCU Emergency Stop) and verify that a message appears flashing in the Fault window.
    • _______(Check)
  3. Acknowledge the fault and verify that the fault message returns to normal video (not flashing).
    • _______(Check)
  4. Activate a second emergency condition and verify new message on the top portion of the screen flashes, the existing message is not flashing but is still visible.
    • _______(Check)
  5. Clear both fault conditions and verify that the first fault message clears and the second remains flashing.
    • _______(Check)
  6. Acknowledge the second fault message and verify that the fault message clears and the system remains disabled.
    • _______(Check)
  7. Verify you can re-enable the axis.
    • _______(Check)
  8. While running the above tests verify the appropriate messages are displayed and logged on the CLEO Message window.

5.4.2 Fault Verification Table

The Fault Message Table below lists the fault messages that will be activated with the appropriate interlock action. Each test shall activate the appropriate switch or mechanism. All fault messages shall be verified to function as described in section 5.4.1.

On the GBT Servo Simulator ALL faults shall be tested with the appropriate axis/axes enabled. On the GBT all faults shall be tested but only a representative subset must be tested with the axis/axes enabled. At least one representative subset shall be tested when the axis/axes are enabled through the M&C and the OCU/OCT.

TABLE INTERLOCK DEFINITION:

Motor Level Disabling (MLD): Disables one motor pair. Brakes are not set and non-disabled motors continue to operate.

Axis Level Disabling(ALD): Brakes are set and motors disabled in affected axis only. Other axis continues to function in selected mode. NOTE: When M&C is in control, ALD will be followed by a SLD from the antenna manager (ACU). The faulted axis enable can be cleared on the ACU, then the non-faulted axis will subsequently enable.

System Level Disabling (SLD): Brakes are set immediately and all motors are disabled. Power to motor armatures are removed (High voltages are still present on motor fields and brake heaters). Soft stop sequence is not exercised. Indicator LEDs on the SWEO motor controllers show enable/disable status.

Non Disabling (ND): All motors continue to function.

FAULT MESSAGE FAULT            
  /LOCATION/ACTION MLD ALD SLD ND OCU M&C
AZ Truck 1 Emergency Activate AZ Truck 1 E-Stop #1     X   ___ ___
AZ Truck 1 Emergency Activate AZ Truck 1 E-Stop #2     X   ___ ___
AZ Truck 1 Emergency Activate AZ Truck 1 E-Stop #3     X   _DONE__ _DONE__
AZ Truck 2 Emergency Activate AZ Truck 2 E-Stop #1     X   ___ ___
AZ Truck 2 Emergency Activate AZ Truck 2 E-Stop #2     X   ___ ___
AZ Truck 2 Emergency Activate AZ Truck 2 E-Stop #3     X   ___ ___
AZ Truck 3 Emergency Activate AZ Truck 3 E-Stop #1     X   ___ ___
AZ Truck 3 Emergency Activate AZ Truck 3 E-Stop #2     X   ___ ___
AZ Truck 3 Emergency Activate AZ Truck 3 E-Stop #3     X   ___ ___
AZ Truck 4 Emergency Activate AZ Truck 4 E-Stop #1     X   ___ ___
AZ Truck 4 Emergency Activate AZ Truck 4 E-Stop #2     X   ___ ___
AZ Truck 4 Emergency Activate AZ Truck 4 E-Stop #3     X   ___ ___
PFF Area Emergency Activate Prime Focus Area E-Stop     X   ___ ___
Turret Activate Turret House E-Stop     X   ___ ___
FeedArm Activate Base of Feed Arm E-Stop     X   ___ ___
Actuator Room Emergency Activate Actuator Room E-Stop     X   ___ ___
Emergency Stop Activate EL Bearing E-Stop     X   ___ ___
Reflector Access Emergency Activate Main Reflector Access E-Stop     X   ___ ___
S/R Area Emergency Activate Subreflector Area E-Stop     X   ___ ___
PFF Activate Prime Focus Feed Room E-Stop     X   ___ ___
EL Drive Emergency Activate EL Drive E-Stop #1     X   ___ ___
EL Drive Emergency Activate EL Drive E-Stop #2     X   ___ ___
Control Room Emergency E-Stop Panel     X   ___ ___
OCU Emergency OCU Front Panel     X   ___ ___
Alidade Room Emergency Activate Alidade Room E-Stop     X   ___ ___
Stairway Emergency Activate E-Stop on Stairway     X   ___ ___
AZ Lockout Activate all Az Lockouts   X     ___ ___
EL Lockout Activate all El Lockouts   X     ___ ___
AZ/EL Lockout Activate all Az/El Lockouts     X   ___ ___
AZ Motor 1 Overtemp Disconnect Wires at AZ1 Thermostat in Motor J-Box X     ___ ___
AZ Motor 2 Overtemp Disconnect Wires at AZ2 Thermostat in Motor J-Box X     ___ ___
AZ Motor 3 Overtemp Disconnect Wires at AZ3 Thermostat in Motor J-Box X     ___ ___
AZ Motor 4 Overtemp Disconnect Wires at AZ4 Thermostat in Motor J-Box X     ___ ___
AZ Motor 5 Overtemp Disconnect Wires at AZ5 Thermostat in Motor J-Box X     ___ ___
AZ Motor 6 Overtemp Disconnect Wires at AZ6 Thermostat in Motor J-Box X     ___ ___
AZ Motor 7 Overtemp Disconnect Wires at AZ7 Thermostat in Motor J-Box X     ___ ___
AZ Motor 8 Overtemp Disconnect Wires at AZ8 Thermostat in Motor J-Box X     ___ ___
AZ Motor 9 Overtemp Disconnect Wires at AZ9 Thermostat in Motor J-Box X     ___ ___
AZ Motor 10 Overtemp Disconnect Wires at AZ10 Thermostat in Motor J-Box X     _DONE__ _DONE__
AZ Motor 11 Overtemp Disconnect Wires at AZ11 Thermostat in Motor J-Box X     ___ ___
AZ Motor 12 Overtemp Disconnect Wires at AZ12 Thermostat in Motor J-Box X     ___ ___
AZ Motor 13 Overtemp Disconnect Wires at AZ13 Thermostat in Motor J-Box X     ___ ___
AZ Motor 14 Overtemp Disconnect Wires at AZ14 Thermostat in Motor J-Box X     ___ ___
AZ Motor 15 Overtemp Disconnect Wires at AZ15 Thermostat in Motor J-Box X     ___ ___
AZ Motor 16 Overtemp Disconnect Wires at AZ16 Thermostat in Motor J-Box X     ___ ___
AZ Motor 1 3-Phase OFF AZ 1 MC Disconnect X       ___ ___
AZ Motor 2 3-Phase OFF AZ 2 MC Disconnect X       ___ ___
AZ Motor 3 3-Phase OFF AZ 3 MC Disconnect X       ___ ___
AZ Motor 4 3-Phase OFF AZ 4 MC Disconnect X       ___ ___
AZ Motor 5 3-Phase OFF AZ 5 MC Disconnect X       ___ ___
AZ Motor 6 3-Phase OFF AZ 6 MC Disconnect X       ___ ___
AZ Motor 7 3-Phase OFF AZ 7 MC Disconnect X       ___ ___
AZ Motor 8 3-Phase OFF AZ 8 MC Disconnect X       ___ ___
AZ Motor 9 3-Phase OFF AZ 9 MC Disconnect X       ___ ___
AZ Motor 10 3-Phase OFF AZ 10 MC Disconnect X       ___ ___
AZ Motor 11 3-Phase OFF AZ 11 MC Disconnect X       ___ ___
AZ Motor 12 3-Phase OFF AZ 12 MC Disconnect X       ___ ___
AZ Motor 13 3-Phase OFF AZ 13 MC Disconnect X       ___ ___
AZ Motor 14 3-Phase OFF AZ 14 MC Disconnect X       ___ ___
AZ Motor 15 3-Phase OFF AZ 15 MC Disconnect X       ___ ___
AZ Motor 16 3-Phase OFF AZ 16 MC Disconnect X       ___ ___
AZ Blower 1 CB OFF AZ 1 Blower X     ___ ___
AZ Blower 2 CB OFF AZ 2 Blower X     ___ ___
AZ Blower 3 CB OFF AZ 3 Blower X     ___ ___
AZ Blower 4 CB OFF AZ 4 Blower X     ___ ___
AZ Blower 5 CB OFF AZ 5 Blower X     ___ ___
AZ Blower 6 CB OFF AZ 6 Blower X     ___ ___
AZ Blower 7 CB OFF AZ 7 Blower X     ___ ___
AZ Blower 8 CB OFF AZ 8 Blower X     ___ ___
AZ Blower 9 CB OFF AZ 9 Blower X     ___ ___
AZ Blower 10 CB OFF AZ 10 Blower X     ___ ___
AZ Blower 11 CB OFF AZ 11 Blower X     ___ ___
AZ Blower 12 CB OFF AZ 12 Blower X     ___ ___
AZ Blower 13 CB OFF AZ 13 Blower X     ___ ___
AZ Blower 14 CB OFF AZ 14 Blower X     ___ ___
AZ Blower 15 CB OFF AZ 15 Blower X     ___ ___
AZ Blower 16 CB OFF AZ 16 Blower X     ___ ___
EL Motor 1 Overtemp Disconnect Wires at EL1 Thermostat in Motor J-Box X       ___ ___
EL Motor 2 Overtemp Disconnect Wires at EL2 Thermostat in Motor J-Box X       ___ ___
EL Motor 3 Overtemp Disconnect Wires at EL3 Thermostat in Motor J-Box X       ___ ___
EL Motor 4 Overtemp Disconnect Wires at EL4 Thermostat in Motor J-Box X       ___ ___
EL Motor 5 Overtemp Disconnect Wires at EL5 Thermostat in Motor J-Box X       ___ ___
EL Motor 6 Overtemp Disconnect Wires at EL6 Thermostat in Motor J-Box X       ___ ___
EL Motor 7 Overtemp Disconnect Wires at EL7 Thermostat in Motor J-Box X       ___ ___
EL Motor 8 Overtemp Disconnect Wires at EL8 Thermostat in Motor J-Box X       ___ ___
EL Motor 1 3-Phase OFF EL 1 MC Disconnect X       ___ ___
EL Motor 2 3-Phase OFF EL 2 MC Disconnect X       ___ ___
EL Motor 3 3-Phase OFF EL 3 MC Disconnect X       ___ ___
EL Motor 4 3-Phase OFF EL 4 MC Disconnect X       ___ ___
EL Motor 5 3-Phase OFF EL 5 MC Disconnect X       ___ ___
EL Motor 6 3-Phase OFF EL 6 MC Disconnect X       ___ ___
EL Motor 7 3-Phase OFF EL 7 MC Disconnect X       ___ ___
EL Motor 8 3-Phase OFF EL 8 MC Disconnect X       ___ ___
EL Motor 1 Blower CB OFF EL 1 Blower X     ___ ___
EL Motor 2 Blower CB OFF EL 2 Blower X     ___ ___
EL Motor 3 Blower CB OFF EL 3 Blower X     ___ ___
EL Motor 4 Blower CB OFF EL 4 Blower X     DONE___ DONE___
EL Motor 5 Blower CB OFF EL 5 Blower X     ___ ___
EL Motor 6 Blower CB OFF EL 6 Blower X     ___ ___
EL Motor 7 Blower CB OFF EL 7 Blower X     ___ ___
EL Motor 8 Blower CB OFF EL 8 Blower X     ___ ___
AZ Brake 1 & 2 CB OFF AZ Brake 1 & 2 CB   X     DONE___ ___
AZ Brake 3 & 4 CB OFF AZ Brake 3 & 4 CB   X     ___ ___
AZ Brake 5 & 6 CB OFF AZ Brake 5 & 6 CB   X     ___ ___
AZ Brake 7 & 8 CB OFF AZ Brake 7 & 8 CB   X     ___ ___
AZ Brake 9 & 10 CB OFF AZ Brake 9 & 10 CB   X     ___ ___
AZ Brake 11 & 12 CB OFF AZ Brake 11 & 12 CB   X     ___ ___
AZ Brake 13 & 14 CB OFF AZ Brake 13 & 14 CB   X     ___ ___
AZ Brake 15 & 16 CB OFF AZ Brake 15 & 16 CB   X     ___ ___
EL Brake 1 & 2 CB OFF EL Brake 1 & 2 CB   X     ___ ___
EL Brake 3 & 4 CB OFF EL Brake 3 & 4 CB   X     ___ ___
EL Brake 5 & 6 CB OFF EL Brake 5 & 6 CB   X     ___ ___
EL Brake 7 & 8 CB OFF EL Brake 7 & 8 CB   X     ___ ___

5.4.3 Brake Fault

The PLC contains circuitry which will disable the motor drives if any brake fails to enable. A fault message will be displayed if the brakes fail to energize or remain released after the axis is disabled. A status switch internal to each brake provides feedback for the circuit.

  1. Disable the EL axis. Enable the azimuth axis from either the OCU or OCT or M&C and verify that the AZ brakes release and the motors enable.
    • ____DONE___(Check)
  2. Create an AZ brake fault by disabling the AZ 1&2 brake circuit breaker. Verify that the AZ axis disables, the brakes set, the motors disable and the fault messages "AZ BRAKE FAULT" and "AZ BRAKE 1&2 CB OFF" appear.
    • __DONE_____(Check)
  3. Reset the circuit breaker. Remove 208 VAC to the interface cabinet. Enable the azimuth axes through the AZ/EL Position Designate window. Verify the axis attempts to enable, then disables and issues the fault message "AZ BRAKE FAULT."
    • _______(Check)
  4. Restore the 208 VAC. Do a PLC Over-Ride to simulate a released brake.
    • _______(Check)
  5. Verify the fault message "AZ DISABLED WITHOUT BRAKE" appears.
    • __ALERT!_____(Check) Works on Elevation only
  6. Repeat steps 1 through 6 for EL.
    1. _______(Check)
    2. _______(Check)
    3. _______(Check)
    4. _______(Check)
    5. _______(Check)

5.4.4 Brake Torque

Brake torque tests will not be performed, the original tests were to verify the original design.

5.4.5 Emergency Stop Active

The Emergency Stop Active relay is used to indicate an emergency stop condition to other units.

  1. Activate an emergency stop switch. Verify that the Emergency Stop Active relay turns on. _______(Check)
  2. Clear the Emergency Stop. Verify that the Emergency Stop Active relay turns off. _______(Check)

5.4.6 Redundant Logic

Not Applicable.

5.4.7 Antenna Oscillation

The CCU provides protection against oscillation conditions. The position encoder feedback is monitored and compared against the position command. If the feedback is measured to be moving symmetrically with a significant magnitude about the command for an extended period of time, the fault is issued and the axis is disabled. In the steps below the symbol 'xx' refers to the axis under test (i.e. 'az' or 'el').
  1. Enable the auxiliary position error input by setting the configuration file key 'configuration.xx.enable_position_error_input' to 'true'.
  2. Verify the key 'components.xx_fault_analysis.enable_oscillation_check' is either missing or set to 'true'.
  3. Restart the CCU process to pickup the configuration change.
  4. Connect a signal generator source to the analog input for the axis under test.
  5. Enable the axis under test using the OCU.
  6. Set the sine wave period to 0.2 Hz or below, and slowly increase the amplitude while monitoring the position error. The check should trigger once the position error is peaking above and below the oscillation check magnitude for the number of cycles listed in the configuration file .
  7. Verify the axis disables, and that messages appear on both the OCU and M&C message screens.
Checks out. Didn't find the config keyword, but set the osc magnitude to around 0.024. Made it oscillate by increasing Kp way up.

5.4.8 MCI / Drive / Motor Loss

5.4.8.1 Azimuth / Elevation axis disable due to motor/drive/MCI loss.

5.4.8.1.1 Azimuth axis disable due to motor/drive loss or MCI Watchdog.
  1. Take control of the CCU with the OCU/OCT and enable the azimuth axis.
  2. Momentarily cause a drive fault on drive/motor "N" by shorting J2-3 (Ready Output) to ground, for that drive. (When shorting the Ready Output in subsequent steps insure it is not the biased pair of a drive already faulted.)
  3. Verify the drive / motor and its torque-biased pair are no longer used in controlling the axis and the axis remains enabled with appropriate fault messages on the OCU/OCT and M&C systems.
    • ___ (Check)
  4. Verify the current command from the two MCIs to their respective drives are zero and the two drives are disabled.
    • ___ (Check)
  5. Momentarily cause a second drive fault on drive/motor "M" by shorting J2-3 (Ready Output) to ground, for that drive.
  6. Verify the drive / motor and its torque-biased pair are no longer used in controlling the axis with appropriate fault messages on the OCU/OCT and M&C systems.
    • ___ (Check)
  7. Verify the current command from the two MCIs to their respective drives are zero and the two drives are disabled.
    • ___ (Check)
  8. Momentarily cause a third drive fault on drive/motor "P" by shorting J2-3 (Ready Output) to ground, for that drive.
  9. Verify the PLC commands a brake sequenced soft-stop with appropriate error messages on the OCU/OCT and M&C systems.
    • ___ (Check)
  10. Verify the CCU disabled the axis.
    • ___ (Check)
  11. Repeat steps 1-9 for a different set of drives / motors for "N" = 1 thru 16.
    • ___ (Check)
  12. Repeat steps 1-10 except force an MCI Watchdog in place of the drive / motor loss. Verify the system responds the same but with the appropriate OCU/OCT and M&C fault messages. The MCI Watchdog shall be initiated on the MCI.
    • ___ (Check)
  13. Take control of the CCU with the M&C system.
    • ___ (Check)
  14. Enable the axis then over-ride a PLC drive input status bit to indicate a drive / motor loss for motor "1".
    • ___ (Check)
  15. Verify the M&C system commands a computer-servoed soft-stop.
    • ___ (Check)
  16. On the simulator repeat steps 14-15 for each azimuth motor. On the GBT select a random subset to test.
    • ___ (Check)
  17. Repeat steps 14-16 except force an MCI Watchdog in place of the PLC drive / motor loss over-ride. Verify the system responds the same but with the appropriate OCU/OCT and M&C fault messages. The MCI Watchdog shall be initiated on the MCI, not through a PLC over-ride bit.
    • ___ (Check)

5.4.8.1.2 Elevation axis disable due to motor/drive loss or MCI Watchdog.

Perform the following tests from the OCU / OCT.
  1. Take control of the CCU with the OCU/OCT and enable the elevation axis.
  2. Momentarily cause a drive fault on drive/motor "N" by shorting J2-3 (Ready Output) to ground, for that drive. (When shorting the Ready Output in subsequent steps insure it is not the biased pair of a drive already faulted.)
  3. Verify the drive / motor and its torque-biased pair are no longer used in controlling the axis and the axis remains enabled with the OCU/OCT and M&C systems displaying the appropriate faults.
    • ___ (Check)
  4. Verify the current command from the two MCIs to their respective drives are zero and the two drives are disabled.
    • ___ (Check)
  5. Momentarily cause a second drive fault on drive/motor "N" by shorting J2-3 (Ready Output) to ground, for that drive.
  6. Verify the PLC commands a brake sequenced soft-stop with the OCU/OCT and M&C systems displaying the appropriate faults.
    • ___ (Check)
  7. Verify the CCU disabled the axis.
    • ___ (Check)
  8. Repeat steps 1-6 for a different set of drives / motors for "N" = 1 thru 8.
    • ___ (Check)
  9. Repeat steps 1-7 except force an MCI Watchdog in place of the drive / motor loss fault. Verify the system responds the same but with the appropriate OCU/OCT and M&C fault messages. The MCI Watchdog shall be initiated on the MCI, not through a PLC over-ride bit.
    • ___ (Check)
  10. Take control of the CCU with the M&C system.
    • ___ (Check)
  11. Enable the axis then over-ride a PLC drive input status bit to indicate a drive / motor loss for motor "1".
    • ___ (Check)
  12. Verify the M&C system commands a computer-servoed soft-stop.
    • ___ (Check)
  13. On the simulator repeat steps 14-15 for each elevation motor. On the GBT select a random subset to test.
    • ___ (Check)
  14. Repeat steps 14-16 except force an MCI Watchdog in place of the drive / motor fault. Verify the system responds the same but with the appropriate OCU/OCT and M&C fault messages. The MCI Watchdog shall be initiated on the MCI.
    • ___ (Check)

5.4.9 Azimuth / Elevation Rate Reductions

5.4.9.1 Azimuth Rate Reduction due to Over-Current

This is function is performed in analog hardware.

5.4.9.2 Azimuth Rate Reduction due to Operator Request

  1. From the OCU request an azimuth rate reduction due to cold weather.
  2. Verify the Main Console, Position Designate and Azimuth Presets windows indicate the maximum rate is 20 deg/min.
    • _DONE__ (Check)
  3. Verify you cannot command the azimuth axis from either window greater than +/- 20 deg/min.
    • _DONE__ (Check)
  4. Take control with M&C.
  5. Verify you cannot command the azimuth axis greater than +/- 20 deg/min from any M&C window.
    • _DONE__ (Check)
  6. Command the CCU a rate greater than 20 deg/min. No sure how to do this. ACU, OCU and both interfaces restrict this
    • Verify the CCU ignores the rate request greater than +/- 20 deg/min.
    • ___ (Check)
  7. Remove the rate reduction restriction with the OCU.
    • Verify the restrictions on the OCU and M&C window are lifted.
    • Verify you can command rates up to 40 deg/min. DONE
  8. From the OCU request an azimuth rate reduction due to cold weather again.
  9. Remove the rate reduction restriction with the M&C.
    • Verify the restrictions on the OCU and M&C window are lifted. DONE
    • Verify you can command rates up to 40 deg/min on the OCU/OCT/M&C computers. DONE
  10. From the M&C request an azimuth rate reduction due to cold weather. DONE
  11. Verify you cannot command the azimuth axis greater than +/- 20 deg/min from any M&C window.
    • _DONE__ (Check)
  12. Verify you can remove the rate reduction from the M&C system.
    • _DONE__ (Check)
  13. From the M&C request an azimuth rate reduction due to cold weather again. DONE
  14. Take control of the system with the OCU/OCT DONE
  15. Verify the Position Designate and Azimuth Presets windows indicate the maximum rate is 20 deg/min.
    • _DONE__ (Check)
  16. Verify you cannot command the azimuth axis from either window greater than +/- 20 deg/min.
    • _DONE__ (Check)
  17. Remove the rate reduction request with the OCU/OCT.
  18. From the OCU/OCT enable azimuth.
  19. Attempt to set or reset the rate reduction from the OCU/OCT.
  20. Verify the mechanism to do so is not visible.
    • ___ (Check)
  21. From the M&C computer enable azimuth.
  22. Verify you can neither set nor reset the azimuth rate reduction while the axis is enabled.
    • _DONE__ (Check)
  23. While in rate reduction mode, restart the CCU.
  24. Verify the CCU/ACU all come up in reduced rate mode.
    • _DONE__ (Check)
  25. Verify the OCU remains in the reduced rate mode.
    • _DONE__ (Check)

5.4.9.3 Elevation Rate Reduction due to Generator Active

  1. From the PLC over-ride the Generator Active bit to indicate the Generator is Active.
  2. The system should start auto-stowing no sooner than 5 seconds and no later than 45 seconds. DONE
  3. Take control of the axis with the OCU. The axis should smoothly decelerate then disable. DONE
    • The Position Designate and Elevation Stow window should indicate the maximum elevation speed is 10 deg/min.
    • _DONE__ (Check)
  4. Attempt to move in elevation from both window at a rate greater than 10 deg/min and verify the input is not accepted.
    • _DONE__ (Check)
  5. Verify you can move at any rate up to +/- 10.0 deg/min.
    • _DONE__ (Check)

5.4.9.4 Elevation Rate Reduction due to MCI / Drive / Motor Loss

  1. From the OCU enable the axis, slew at +/-20 deg/min, then over-ride a PLC drive input status bit to indicate a drive / motor loss.
  2. Verify the axis rate is smoothly decreased to 90% of the rated speed of the motors.
    • (0.9 * 1150/1750) * 20 deg/min = 11.8 deg/min)
    • ___ (Check)
  3. Verify the maximum allowable elevation axis rate is now set to 10.0 deg/min by inspecting the maximum rate the OCU will allow you to enter on the Position Designate and Elevation Stow windows and attempting to change the rate to greater than 10.0 deg/min.
    • _DONE__ (Check)
  4. Repeat step 1 with the M&C system in control and verify the CCU performs a computer servoed softstop.
    • ___ (Check)

5.4.9.5 Elevation Rate Reduction due to Over-Current (To Be Designed by Tim)

5.4.10 Azimuth Acceleration Reduction due to Generator Active

  1. From the PLC over-ride the Generator Active bit to indicate the Generator is Active.
  2. The system should start auto-stowing in elevation no sooner than 5 seconds and no later than 45 seconds.
  3. Take control of the axis with the OCU/OCT. The axis should smoothly decelerate then disable.
  4. Enable the azimuth axis and slew to a point 10 degrees away.
  5. From the tachometer data verify the maximum acceleration and deceleration is 0.05 deg/sec/sec.
  6. Disable the azimuth axis.

5.4.11 Azimuth / Elevation Tachometer Tests.

5.4.11.1 Delta Encoder Positions compared with Integrated Tachometers Cant test in lab

The CCU compares the integrated value of the average tach signal with the change in encoder position once per second. This test will attempt to trigger the check. In the descriptions below the notation 'xx' refers to either az or el, depending upon the axis under test.
  1. Stop the CCU process.
  2. Verify that the configuration keyword 'components.xx_fault_analysis.enable_tach_encoder_check' is either not present or has a value of '1'.
  3. Modify the configuration value 'components.el_analog.input_gains' at index 24 (azimuth) and index 28 (elevation), counting from 0. (i.e. the 8th and 4th channels from the end respectively) to a value 15% below the normal value.
  4. Start the CCU process.
  5. Using the OCU, enable the axis under test.
  6. Verify axes do not disable. Note this change will impact loop gain slightly, so take care to watch for stability issues.
  7. Command a move of 10 degrees.
  8. Verify that the tach vs. encoder error message appears, and the axis disables.
    • ___ (Check [AZ])
    • ___ (Check [EL])
  9. Repeat for the elevation axis.
  10. Restore the previous values in the configuration file and restart the CCU process.

5.4.11.2 Azimuth Tachometer Feedback exceeds +/- 10% of average tachometer feedback.

  1. Enable the azimuth axis through M&C and command it to a distant position at 50% maximum rate.
  2. Cause the tachometer feedback from one of the MCIs to indicate a rate of more than 60% maximum rate.
    • (This can be done by either tweaking the tachometer calibration potentiometer for an MCI or through one of the test bits Kevin is providing, which will tell the MCI to offset the tachometer by greater than 10%.)
  3. Verify the M&C and OCU activate a warning message indicating which tachometer is at fault, the axis will not be disabled.
  4. Repeat steps 1-3 except set the indicated tachometer rate to less than 40% of the maximum rate.
    • ___ (Check)

5.4.11.3

5.4.11.4 Elevation Tachometer Feedback exceeds +/- 10% of average tachometer feedback.

  1. Enable the elevation axis through M&C and command it to a distant position at 50% maximum rate.
  2. Cause the tachometer feedback from one of the MCIs to indicate a rate of more than 60% maximum rate.
    • (This can be done by either tweaking the tachometer calibration potentiometer for an MCI or through one of the test bits Kevin is providing, which will tell the MCI to offset the tachometer by greater than 10%.)
  3. Verify the M&C and OCU activate a warning message indicating which tachometer is at fault, the axis will not be disabled.
    • ___ (Check)
  4. Repeat steps 1-3 except set the indicated tachometer rate to less than 40% of the maximum rate.
    • ___ (Check)

5.4.12 Azimuth / Elevation Position Encoder Tests.

(Simulator test to verify software. GBT test to verify we do not have false failures.)

5.4.12.1 Azimuth Position Encoder Jumps.

The purpose of the CCU software which checks for encoder jumps is not to verify the axis had moved too far in a given time. The purpose is to detect stuck bits. Given this the software is trying to detect stuck bits as low to the lsb as possible with no false detections. At maximum slew the azimuth encoder will show a maximum position displacement of 0.000667 deg/ms. This translates into 2.4 arc-sec/ms. To guarantee no false detections we multiply the maximum position displacement/ms by 3 and come up with 7.2 arc-seconds/ms. 7.2 arc-seconds corresponds to a binary count of 24 on the encoder or 5 encoder bits, assuming the weight of the encoder lsb is 0.3 arc-seconds. Therefore this acceptance test procedure needs to set bit 5 (bit 0 being the lsb) and any other higher order bit to get the software test to fail.

This test needs to be checked on the simulator that it fails properly and tested on the GBT to verify it does not fail in normal conditions.

  1. Verify the configuration keyword 'components.az_fault_analysis.enable_encoder_jump_check' is either missing, or has a value of 1.
  2. Through the PEI interface force bit 5 (bit 0 being lsb) to remain in either a 0 or 1 state.
  3. Verify the software flags an encoder position jump and disables the axis.
    • ___ (Check)
  4. Through the PEI interface force random bit n (22>n>5) to remain in either a 0 or 1 state.
  5. Verify the software flags an encoder position jump and disables the axis.
    • ___ (Check)

5.4.12.2 Elevation Position Encoder Jumps.

This test needs to be checked on the simulator that it fails properly and tested on the GBT to verify it does not fail in normal conditions.

  1. Verify the configuration keyword 'components.az_fault_analysis.enable_encoder_jump_check' is either missing, or has a value of 1.
  2. Through the PEI interface force bit 5 (bit 0 being lsb) to remain in either a 0 or 1 state.
  3. Verify the software flags an encoder position jump and disables the axis.
    • ___ (Check)
  4. Through the PEI interface force random bit n (22>n>5) to remain in either a 0 or 1 state.
  5. Verify the software flags an encoder position jump and disables the axis.
    • ___ (Check)

5.4.13 Azimuth / Elevation axis disable due to Control Envelope Limit

(TBD)

5.5 LOOP TESTS (To Be Designed by Kevin and Tim)

This section to be completed after we define the trajectories and determine which interface is sufficient to execute them. (For reference, the original trajectories can be found in the original 2000 Servo Site Acceptance Test Procedures.)
  • 5.5.1 Running Current / Balance
  • 5.5.2 Rate Loop Tests
  • 5.5.3 Position Loop Tests

5.5.1 Running Current / Balance

5.5.2 Rate Loop Tests

The rate loop is tested for minimum smooth velocity (MSV), bandwidth, step response, acceleration and Locked Rotor Resonance. This section to be completed after we define the trajectories and determine which interface is sufficient to execute them. (For reference, the original trajectories can be found in the original 2000 Servo Site Acceptance Test Procedures.)

5.5.2.1 Minimum Smooth Velocity

5.5.2.2 Rate Loop Step Response

5.5.2.3 Rate Loop Phase & Gain Margin

5.5.3 Position Loop Tests

5.5.3.1 Position Loop Step Response

5.5.3.2 Position Loop Bandwidth Phase Margin & Gain Margin

5.5.4 Computer Servo Enabling

This set of tests will verify the system can be safely enabled. Before running the first two tests the antenna shall be moved in azimuth and elevation to at least 40 degrees from their position limits. This can be done with the original servo system.

5.5.4.1 Computer Servo Enabling Azimuth

The following tests require the Servo Monitor or a data logger to be logging the azimuth position encoder and all the tachometers and all motor currents at no less than 50 samples/second. All verifications which are not visual shall be verified through this data or through another instrument of choice. (Proper brake pair release order is 1&2, 3&4, 4&6, 7&8, 9&10, 11&12, 13&14, 15&16. Brakes are commanded to release in 0.2 second intervals. The CCU shall command zero rate prior to enabling, and shall hold zero rate until after all brakes have been commanded to release or 1.6 seconds after the first brake is commanded to release. (The drives are commanded to enable, from the PLC, at 1.6 seconds.) Position loop closure begins as soon as all brakes indicate they are released.

  1. Through the OCU Position Designate window enable the azimuth axis with no commanded movement.
  2. Visually verify brakes release synchronously and in proper order and timing.
    • ___ (Check)
  3. Visually verify the drives enable in proper timing.
    • ___ (Check)
  4. In azimuth the PLC commands the last set of brakes to release 1.4 seconds after the axis is declared to be active (aAxisP or aAxisN being true define the axis as being active). The kernel shall be controlling the axis no sooner than 1.4 seconds and no later than 1.6 seconds after the axis is active. Verify the Kernel begins controlling at the correct time.
    • _______Milli-Seconds (With an O-Scope measure when MCI DACs start commanding motor current relative to when the last brake is commanded to release.)
    • Visually verify the transition between the azimuth axis being held by the brakes to being controlled by the servo system is smooth.
    • ___ (Check)
  5. Verify the torque biasing is applied timely and smoothly by reviewing the motor currents in the logs.
    • _______(Check)
  6. Verify torque bias pairing
    • ___ (Check)
  7. Verify torque bias magnitudes
    • ___ (Check)
  8. Verify torque bias directions
    • ___ (Check)
  9. Measure total axis movement from when the axis was held by the brakes to when it is being held by the servo system with full torque bias applied. ___ (Degrees)
    • ___ (Check)
  10. Measure peak axis displacement during this transition period. ___ (Degrees)
  11. Repeat steps 1 - 10 with M&C in control.
  12. Verify the measurements while being controlled by the OCU are the same as when controlled by M&C, if not then determine why they are different.
    • ___ (Check)

5.5.4.2 Computer Servo Enabling Elevation at 50 degrees.

The following tests require the Servo Monitor or a data logger to be logging the elevation position encoder and all the tachometers and all motor currents at no less than 50 samples/second. All verifications which are not visual shall be verified through this data or through another instrument of choice. (Proper brake pair release order is 1&2, 3&4, 4&6, 7&8. Brakes are commanded to release in 0.3 second intervals. The Kernel shall be in control 0.3 seconds after all brakes have been commanded to release or 1.5 seconds after the first brake is commanded to release. The drives are commanded to enable, from the PLC, at 1.5 seconds.)

  1. Through the OCU Position Designate window enable the axis with no commanded movement.
  2. Visually verify brakes release synchronously and in proper order and timing.
    • ___ (Check)
  3. Visually verify the drives enable in proper timing.
    • ___ (Check)
  4. In elevation the PLC commands the last set of brakes to release 0.9 seconds after the axis is declared to be active (eAxisP or eAxisN being true define the axis as being active). The kernel shall be controlling the axis no sooner than 0.9 seconds and no later than 1.5 seconds after the axis is active. Verify the Kernel begins controlling at the correct time.
    • _______Milli-Seconds (With an O-Scope measure when MCI DACs start commanding motor current relative to when the last brake is commanded to release.)
    • Visually verify the transition between the elevation axis being held by the brakes to being controlled by the servo system is smooth.
    • ___ (Check)
  5. Verify the torque biasing is applied timely and smoothly by reviewing the motor currents in the logs.
    • _______(Check)
  6. Verify torque bias pairing
    • ___ (Check)
  7. Verify torque bias magnitudes
    • ___ (Check)
  8. Verify torque bias directions
    • ___ (Check)
  9. Measure total axis movement from when the axis was held by the brakes to when it is being held by the servo system with full torque bias applied. ___ (Degrees)
  10. Measure peak axis displacement during this transition period. ___ (Degrees)
  11. Repeat steps 1 - 10 with M&C in control.
  12. Verify the measurements while being controlled by the OCU are the same as when controlled by M&C, if not then determine why they are different.
    • ___ (Check)

5.5.4.3 Computer Servo Enabling Elevation at 90 degrees.

Do not perform this test for initial system checkout.
  1. Repeat section 5.5.4.2 with elevation axis positioned at 90 degrees.
    • _______(Check)
  2. Verify all measurements are similiar to elevation at 50 degrees and investigate if / when they are different.
    • _______(Check)

5.5.4.4 Computer Servo Enabling Elevation at 5 degrees.

Do not perform this test for initial system checkout.
  1. Repeat section 5.5.4.2 with elevation axis positioned at 5 degrees.
    • _______(Check)
  2. Verify all measurements are similiar to elevation at 50 degrees and investigate if / when they are different.
    • _______(Check)

5.5.5 Computer Servo Moving (Run the following tests alternating randomly through the three different computer interfaces when convenient, M&C, OCU and OCT.)

5.5.5.1 Computer Servo Moving in Azimuth up to 1/4 speed.

  1. Command movement from rest to 1/4 full speed.
  2. Verify axis acceleration of 0.1 deg/sec/sec. ___ (Check)
  3. Verify axis rate. ___ (Check)
  4. Command movement from 1/4 full speed to rest.
  5. Verify axis deceleration of ~ -0.1 deg/sec/sec. ___ (Check)
  6. Verify axis rate smoothly goes to zero. ___ (Check)
  7. Monitor and verify proper torque biases throughout the tests. ___ (Check)

5.5.5.2 Computer Servo Moving in Azimuth up to 1/2 speed.

Do not perform this test for initial system checkout.
  1. Command movement with 0.1 deg/sec/sec acceleration from rest to 1/2 full speed.
  2. Verify axis acceleration. ___ (Check)
  3. Verify axis rate. ___ (Check)
  4. Command movement from 1/2 full speed to rest.
  5. Verify axis acceleration. ___ (Check)
  6. Verify axis rate. ___ (Check)
  7. Monitor and verify proper torque biases throughout the tests. ___ (Check)

5.5.5.3 Computer Servo Moving in Azimuth up to full speed.

Do not perform this test for initial system checkout.
  1. Command movement with 0.1 deg/sec/sec acceleration from rest to full speed in HI rate mode.
  2. Verify axis acceleration. ___ (Check)
  3. Verify axis rate. ___ (Check)
  4. Command movement from full speed to rest.
  5. Verify axis acceleration. ___ (Check)
  6. Verify axis decelerates smoothly at -0.1 deg/sec/sec ___ (Check)
  7. Monitor and verify proper torque biases throughout the tests. ___ (Check)
  8. Verify the torque biases properly transitioned out when we increased in rate, before we got to full speed. Note the speed at which they began to transition. ___ (Deg/Min)
  9. Verify the torque biases properly transitioned in when we decreased in rate and note the speed at which they began to transition. ___ (Check)

5.5.5.4 Computer Servo Moving in Elevation up to 1/4 full speed.

  1. Command movement from rest to 1/4 full speed.
  2. Verify axis acceleration. ___ (Check)
  3. Verify axis rate. ___ (Check)
  4. Command movement from 1/4 full speed to rest.
  5. Verify axis acceleration. ___ (Check)
  6. Verify axis decelerates smoothly at -0.1 deg/sec/sec. ___ (Check)
  7. Monitor and verify proper torque biases throughout the tests. ___ (Check)

5.5.5.5 Computer Servo Moving in Elevation up to 1/2 speed.

Do not perform this test for initial system checkout.
  1. Command movement from rest to 1/2 full speed.
  2. Verify axis acceleration. ___ (Check)
  3. Verify axis rate. ___ (Check)
  4. Command movement from 1/2 full speed to rest.
  5. Verify axis acceleration. ___ (Check)
  6. Verify axis decelerates smoothly at -0.1 deg/sec/sec. ___ (Check)
  7. Monitor and verify proper torque biases throughout the tests. ___ (Check)

5.5.5.6 Computer Servo Moving in Elevation up to full speed.

Do not perform this test for initial system checkout.
  1. Command movement from rest to full speed.
  2. Verify axis acceleration. ___ (Check)
  3. Verify axis rate. ___ (Check)
  4. Command movement from full speed to rest.
  5. Verify axis acceleration. ___ (Check)
  6. Verify axis decelerates smoothly at -0.1 deg/sec/sec. ___ (Check)
  7. Monitor and verify proper torque biases throughout the tests. ___ (Check)
  8. Monitor, log, and verify proper field currents throughout the tests as a function of speed at one degree intervals. ___ (Check)
  9. The elevation axis will not transition into and out of torque biasing at any speed during normal operation. We need a large wind or snow / ice load. We need a test to verify elevation will properly transition in and out of torque biasing. (This could be as simple as temporarily increasing the elevation torque bias.)

5.5.6 Computer Servo Disabling (This section was defined for the Digital Rate Loop testing. These tests have already been performed for the analog rate loop boards and do not need to be re-tested.)

The purpose of these tests is to verify computer servoed soft-stops, brake sequenced soft-stops and hard-stops. These tests shall be executed with the M&C, OCU and the OCT in random order of control.

  1. Move the azimuth axis to a safe distance from the axis position limits and move the elevation axis to survival in a safe manner. Verify an E-STOP (Hard-Stop) for azimuth at zero rate.
    • ___ 0 Deg/Min.
  2. Move the azimuth axis to a safe distance from the axis position limits and move the elevation axis to survival while in manual control. Verify an E-STOP (Hard-Stop) for elevation at zero rate.
    • ___ 0 Deg/Min.
(For initial system check out perform tests up to 5 Deg/Min only)
  1. Move the azimuth axis to a safe distance from the axis position limits and move the elevation axis to survival. Verify computer servoed stopping, by commanding an axis disable from the unit in control, from the following rates for azimuth:
    • ___ 0 Deg/Min.
    • ___ 5 Deg/Min.
    • ___ 10 Deg/Min.
    • ___ 20 Deg/Min.
    • ___ 40 Deg/Min.
  2. Move the azimuth axis to a safe distance from the axis position limits and move the elevation axis to survival. Verify computer servoed stopping, by commanding an axis disable from the unit in control, from the following rates for elevation:
    • ___ 0 Deg/Min.
    • ___ 5 Deg/Min.
    • ___ 10 Deg/Min.
    • ___ 20 Deg/Min.
  3. Move the azimuth axis to a safe distance from the axis position limits and move the elevation axis to survival. Verify PLC brake sequenced soft-stopping, by forcing a CCU-PLC watchdog, from the following rates for azimuth:
    • ___ 0 Deg/Min.
    • ___ 5 Deg/Min.
    • ___ 10 Deg/Min.
    • ___ Wait 10 minutes for brakes to cool.
    • ___ 20 Deg/Min.
    • ___ Wait 20 minutes for brakes to cool.
    • ___ 40 Deg/Min.
    • ___ Wait 20 minutes for brakes to cool.
  4. Move the azimuth axis to a safe distance from the axis position limits and move the elevation axis to survival. Verify PLC brake sequenced soft-stopping, by forcing a CCU-PLC watchdog, from the following rates for elevation:
    • ___ 0 Deg/Min.
    • ___ 5 Deg/Min.
    • ___ 10 Deg/Min.
    • ___ Wait 10 minutes for brakes to cool.
    • ___ 20 Deg/Min.
    • ___ Wait 20 minutes for brakes to cool.

5.6 TIMING TEST

The OCU uses Microsoft Windows to insure its clock is correct. The CCU uses an IRIG-B card to get its clock and timing.

5.6.1 OCU Timing Reference

The new OCU gets its timing reference through Microsoft windows. Normally windows machines use the AD domain to synchronize time. Since the OCU/OCT are isolated from the AD domain, the CCU provides the time service instead.

  1. Verify the OCU and OCT can obtain time from the CCU by running the windows command 'ntpq -p'. This should print information about the time offset between the two systems, and should list the CCU as a 'stratum 1' peer. (Does the ntpq command exist on windows? Cigwin ?)
    • ___ (Check)
  2. Visually verify the clock on the OCU and OCT are correct.

5.6.2 CCU Timing Reference

The CCU uses an IRIG decoder card which receives a maser stabilized time signal. The CCU process cycles are driven from the IRIG card 50 Hz interrupts. In addition, the CCU system time is synchronized using a separate process 'ntp_helper' to bridge between the IRIG card and ntpd daemon.

If the IRIG signal is lost, a message indicating signal the loss will appear, and operation will be unsynchronized. This may impact astronomical observations. To test:
  1. Enable the elevation axis through the OCU or M&C.
  2. Run the following command on the CCU host computer:
    • ntpq -p
           remote           refid      st t when poll reach   delay   offset  jitter
      ==============================================================================
        ...
      *SHM(0)          .SHM.            0 l   42   64  377    0.000   -0.040   0.006
      
  1. Verify there is an asterisk next to the line containing the word 'SHM', and 'reach' is 377 (similar to the example above). _______(Check)
  2. Disconnect the IRIG signal from the CCU host computer
  3. Verify the message IRIG signal loss appears. Note: The message may take a few minutes to appear, this is normal. _______(Check)
  4. Verify the axes do not disable. _______(Check)
  5. Re-run the command from step 2 a few minutes apart.
  6. Verify that the reach field changes to a value other than 377. _______(Check)
  7. Reconnect the IRIG signal to the CCU host computer, and verify the reach field eventually returns to 377.
  8. Verify that the IRIG signal loss message clears.

5.7 Tracking Stability

The following tests will demonstrate the tracking stability of the antenna.

  1. Set system loggers to record azimuth and elevation position and position error.
    • Note the UTC Date and Time: ________________________
    • _______(Check)
  2. From the OCU / OCT Position Designate window ENABLE both axes then MOVE to a position 10 degrees from where you are presently located.
    • _______(Check)
  3. Record the position error once the antenna has reached the designated position.
    • AZ Position Error __________ (Record)
    • EL Position Error __________ (Record)
  4. Verify that the Limit Cycle in both axes is less than 1.5 Arc sec (5 LSB's).
    • _______(Check)
  5. Repeat steps 1-5 above with M&C in control.

5.8 TRAVEL RANGE/LIMITS

The following tests will verify the travel range of the telescope and demonstrate the limit operation. The azimuth axis is capable of a minimum of +/- 270 deg about the cable wrap null point of 180 deg due south. The telescope will have limit switches mounted at the extremes of travel in both axes. In addition, software limits will prevent the telescope from driving beyond the travel range during position loop operations.

Software Limit: The software limit is set in the CCU. The OCU and M&C monitors commands and position feedback, initiating warning if either exceeds the software limit.

Prelimit: The prelimit will be checked to verify that when activated, brakes are set and the motors disabled Upon depression of the (PMU or MRU) override switch, the motors are enabled and may be driven out of limit but not further into limit.

Final Limit: The final limits will be checked to verify that, when activated, the brakes are set, the motors disabled and the condition cannot be overridden.

HVIC Limit: The HVIC Limits will trip the input CB (Shunt-Trip Breakers) which provides motor power to the PDUs.

Limit Bypass: The limit bypass switch will override all azimuth and elevation limits.

5.8.1 AZIMUTH CW Limits

When asked to jumper out a limit, the tester may use DirectSoft to over-ride the limit in the PLC on all limits but the final limits. The PLC cannot over-ride the final limits.

  1. Using the M&C computer, command the azimuth position to the CW travel limit (450.1 deg CW). Verify that the telescope drives to the commanded position and indication is CW. The software limit may appear due to position overshoot. Clear the fault message if it appears.
    • _______(Check)
  2. Using the MRU, slowly drive the telescope through the software limit. Verify that the fault message "AZ + SOFTWARE LIMIT" appears as the position passes through the software limit (Need this number.)
    • _______(Check)
  3. With the axis in the limit condition, using the M&C computer, verify that commands out of the limit are executed.
    • _______(Check)
  4. Using the MRU, slowly drive CW into the CW Prelimit.
    • _______(Check)
  5. Record the angle at which the prelimit is activated. Verify that the brakes are set. Using the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • CW Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • No Further CW Movement ________(Check)
    • MRU Bypass _______(Check)
  6. Verify that the fault message "AZ CW PRELIMIT" is displayed and the proper messages are displayed on the M&C and OCU/OCT displays.
    • _______(Check)
  7. Jumper the prelimit and slowly drive the antenna CW until the redundant prelimit is activated.
    • _______(Check)
  8. Record the angle at which the redundant prelimit is activated. Verify that the brakes are set. On the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • No Further CW Movement ________(Check)
    • CW Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • MRU Bypass _______(Check)
  9. Verify that the fault message "AZ CW REDUNDT PL" is displayed and the station alarms are activated.
    • _______(Check)
  10. Jumper the redundant prelimit and slowly drive the telescope CW until the final limit is activated. Record the CW Final Limit position.
    • CW Final Limit ______________(Record)
  11. Verify that the brakes are set and the motors disabled.
    • _______(Check)
  12. Verify MRU commands do not enable the motors.
    • _______(Check)
  13. Verify that the fault message "AZ CW FINAL LIMIT" is displayed and the station alarms are activated.
    • _______(Check)
  14. Activate the AZ Final Limit Bypass switch and verify that the limit clears and the axis can be enabled.
    • _______(Check)
  15. Release the AZ Final Limit Bypass switch.
    • _______(Check)
  16. Jumper the limit and slowly drive CW until the Redundant Final Limit is activated. Record the CW Redundant Final limit.
    • CW Redundant Final Limit ______________(Record)
  17. Verify that all four shunt trip circuit breakers are activated, 480 VAC drive power is removed from the PDU's and the brakes are set.
    • _______(Check)
  18. Verify that Motor Controller fault messages appear for all motors. Verify that the "HIGH VOLTAGE INTERLOCK" AND "AZ BRAKE LIMIT" messages appear and the station alarms are activated.
    • _______(Check)
  19. Clear all limits and remove all bypass jumpers. While depressing the limit override, reenable the circuit breakes to the PDU tripped by the high voltage interlock and slowly drive out until the limits are cleared.
    • _______(Check)

5.8.2 AZIMUTH CCW Limits

When asked to jumper out a limit, the tester may use DirectSoft to over-ride the limit in the PLC on all limits but the final limits. The PLC cannot over-ride the final limits.

  1. Using the M&C computer, command the azimuth position to the CCW travel limit (-90.1 deg CCW). Verify that the telescope drives to the commanded position and indication is CCW. The software limit may appear due to position overshoot. Clear the fault message if it appears.
    • _______(Check)
  2. Using the MRU, slowly drive the telescope through the software limit. Verify that the fault message "AZ - SOFTWARE LIMIT" appears as the position passes through the software limit (Need this number.)
    • _______(Check)
  3. With the axis in the limit condition, using the M&C computer, verify that commands out of the limit are executed.
    • _______(Check)
  4. Using the MRU, slowly drive CCW into the CCW Prelimit.
    • _______(Check)
  5. Record the angle at which the prelimit is activated. Verify that the brakes are set. Using the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • CCW Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • No Further CCW Movement ________(Check)
    • MRU Bypass _______(Check)
  6. Verify that the fault message "AZ CCW PRELIMIT" is displayed and the proper messages are displayed on the M&C and OCU/OCT displays.
    • _______(Check)
  7. Jumper the prelimit and slowly drive the antenna CCW until the redundant prelimit is activated.
    • _______(Check)
  8. Record the angle at which the redundant prelimit is activated. Verify that the brakes are set. On the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • No Further CCW Movement ________(Check)
    • CCW Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • MRU Bypass _______(Check)
  9. Verify that the fault message "AZ CCW REDUNDT PL" is displayed and the station alarms are activated.
    • _______(Check)
  10. Jumper the redundant prelimit and slowly drive the telescope CCW until the final limit is activated. Record the CCW Final Limit position.
    • CCW Final Limit ______________(Record)
  11. Verify that the brakes are set and the motors disabled.
    • _______(Check)
  12. Verify MRU commands do not enable the motors.
    • _______(Check)
  13. Verify that the fault message "AZ CCW FINAL LIMIT" is displayed and the station alarms are activated.
    • _______(Check)
  14. Activate the AZ Final Limit Bypass switch and verify that the limit clears and the axis can be enabled.
    • _______(Check)
  15. Release the AZ Final Limit Bypass switch.
    • _______(Check)
  16. Jumper the limit and slowly drive CCW until the Redundant Final Limit is activated. Record the CCW Redundant Final limit.
    • CCW Redundant Final Limit ______________(Record)
  17. Verify that all four shunt trip circuit breakers are activated, 480 VAC drive power is removed from the PDU's and the brakes are set.
    • _______(Check)
  18. Verify that Motor Controller fault messages appear for all motors. Verify that the "HIGH VOLTAGE INTERLOCK" AND "AZ BRAKE LIMIT" messages appear and the station alarms are activated.
    • _______(Check)
  19. Clear all limits and remove all bypass jumpers. While depressing the limit override, reenable the circuit breakers to the PDU tripped by the high voltage interlock and slowly drive out until the limits are cleared.
    • _______(Check)

5.8.3 Elevation Down Limits

When asked to jumper out a limit, the tester may use DirectSoft to over-ride the limit in the PLC on all limits but the final limits. The PLC cannot over-ride the final limits.

  1. Using the M&C computer, command the elevation position to the DOWN travel limit (4.9 deg). Verify that the telescope drives to the commanded position. The software limit may appear due to position overshoot. Clear the fault message if it appears.
    • _______(Check)
  2. Using the MRU, slowly drive the telescope through the software limit. Verify that the fault message "EL - SOFTWARE LIMIT" appears as the position passes through the software limit (Need this number.)
    • _______(Check)
  3. With the axis in the limit condition, using the M&C computer, verify that commands out of the limit are executed.
    • _______(Check)
  4. Using the MRU, slowly drive DOWN into the DOWN Prelimit.
    • _______(Check)
  5. Record the angle at which the prelimit is activated. Verify that the brakes are set. Using the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • DOWN Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • No Further DOWN Movement ________(Check)
    • MRU Bypass _______(Check)
  6. Verify that the fault message "EL DOWN PRELIMIT" is displayed and the proper messages are displayed on the M&C and OCU/OCT displays.
    • _______(Check)
  7. Jumper the prelimit and slowly drive the antenna DOWN until the redundant prelimit is activated.
    • _______(Check)
  8. Record the angle at which the redundant prelimit is activated. Verify that the brakes are set. On the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • No Further DOWN Movement ________(Check)
    • DOWN Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • MRU Bypass _______(Check)
  9. Verify that the fault message "EL DOWN REDUNDT PL" is displayed and the station alarms are activated.
    • _______(Check)
  10. Jumper the redundant prelimit and slowly drive the telescope DOWN until the final limit is activated. Record the DOWN Final Limit position.
    • DOWN Final Limit ______________(Record)
  11. Verify that the brakes are set and the motors disabled.
    • _______(Check)
  12. Verify MRU commands do not enable the motors.
    • _______(Check)
  13. Verify that the fault message "EL DOWN FINAL LIMIT" is displayed and the station alarms are activated.
    • _______(Check)
  14. Activate the EL Final Limit Bypass switch and verify that the limit clears and the axis can be enabled.
    • _______(Check)
  15. Release the EL Final Limit Bypass switch.
    • _______(Check)
  16. Jumper the limit and slowly drive DOWN until the Redundant Final Limit is activated. Record the DOWN Redundant Final limit.
    • DOWN Redundant Final Limit ______________(Record)
  17. Verify that all four shunt trip circuit breakers are activated, 480 VAC drive power is removed from the PDU's and the brakes are set.
    • _______(Check)
  18. Verify that Motor Controller fault messages appear for all motors. Verify that the "HIGH VOLTAGE INTERLOCK" AND "EL BRAKE LIMIT" messages appear and the station alarms are activated.
    • _______(Check)
  19. Clear all limits and remove all bypass jumpers. While depressing the limit override, reenable the circuit breakes to the PDU tripped by the high voltage interlock and slowly drive out until the limits are cleared.
    • _______(Check)

5.8.4 Elevation Up Limits

When asked to jumper out a limit, the tester may use DirectSoft to over-ride the limit in the PLC on all limits but the final limits. The PLC cannot over-ride the final limits.

  1. Using the M&C computer, command the elevation position to the UP travel limit (95.1 deg). Verify that the telescope drives to the commanded position. The software limit may appear due to position overshoot. Clear the fault message if it appears.
    • _______(Check)
  2. Using the MRU, slowly drive the telescope through the software limit. Verify that the fault message "EL - SOFTWARE LIMIT" appears as the position passes through the software limit (Need this number.)
    • _______(Check)
  3. With the axis in the limit condition, using the M&C computer, verify that commands out of the limit are executed.
    • _______(Check)
  4. Using the MRU, slowly drive UP into the UP Prelimit.
    • _______(Check)
  5. Record the angle at which the prelimit is activated. Verify that the brakes are set. Using the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • UP Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • No Further UP Movement ________(Check)
    • MRU Bypass _______(Check)
  6. Verify that the fault message "EL UP PRELIMIT" is displayed and the proper messages are displayed on the M&C and OCU/OCT displays.
    • _______(Check)
  7. Jumper the prelimit and slowly drive the antenna UP until the redundant prelimit is activated.
    • _______(Check)
  8. Record the angle at which the redundant prelimit is activated. Verify that the brakes are set. On the MRU, continuously depress the axis enable. Verify that the axis enables, will not allow further movement into the limit and drives out of limit.
    • No Further UP Movement ________(Check)
    • UP Prelimit ______________(Record)
    • Motors Disabled _______(Check)
    • Brakes Set _______(Check)
    • MRU Bypass _______(Check)
  9. Verify that the fault message "EL UP REDUNDT PL" is displayed and the station alarms are activated.
    • _______(Check)
  10. Jumper the redundant prelimit and slowly drive the telescope UP until the final limit is activated. Record the UP Final Limit position.
    • UP Final Limit ______________(Record)
  11. Verify that the brakes are set and the motors disabled.
    • _______(Check)
  12. Verify MRU commands do not enable the motors.
    • _______(Check)
  13. Verify that the fault message "EL UP FINAL LIMIT" is displayed and the station alarms are activated.
    • _______(Check)
  14. Activate the EL Final Limit Bypass switch and verify that the limit clears and the axis can be enabled.
    • _______(Check)
  15. Release the EL Final Limit Bypass switch.
    • _______(Check)
  16. Jumper the limit and slowly drive UP until the Redundant Final Limit is activated. Record the UP Redundant Final limit.
    • UP Redundant Final Limit ______________(Record)
  17. Verify that all four shunt trip circuit breakers are activated, 480 VAC drive power is removed from the PDU's and the brakes are set.
    • _______(Check)
  18. Verify that Motor Controller fault messages appear for all motors. Verify that the "HIGH VOLTAGE INTERLOCK" AND "EL BRAKE LIMIT" messages appear and the station alarms are activated.
    • _______(Check)
  19. Clear all limits and remove all bypass jumpers. While depressing the limit override, reenable the circuit breakes to the PDU tripped by the high voltage interlock and slowly drive out until the limits are cleared.
    • _______(Check)

5.9 OCU

  • Acronyms used in this section:
  1. OCU - Operator Control Unit
  2. OCT - Operator Control Terminal (Obsolete, use VNC instead)
  3. PMU - Portable Maintenance Unit
  4. MRU - Manual Rate Unit
  5. MSU - Manual Stow Unit
  6. AE HALT - Azimuth / Elevation Halt
  7. SR HALT - Subreflector HALT
  8. PF HALT - Prime Focus HALT
  9. TU HALT - Turret HALT

5.9.1 OCU Main Console

5.9.1.1 OCU ALL STOP

The OCU All Stop disables all azimuth and elevation mechanisms, and later feed arm drives, and sets the brakes after a controlled deceleration. In the final configuration the All Stop command is a combination of AE HALT, SR HALT, PF HALT, and TU HALT. In this system deployment it will only command azimuth and elevation mechanisms. These mechanisms are azimuth drives, elevation drives and elevation stow pin.

  1. Enable both axes from the AZ/EL Position Designate window.
    • _______(Check)
  2. Execute the All Stop mode and verify that the motors decelerate, the brakes are set and the motor controllers disabled.
    • _______(Check)
  3. Move to a valid elevation stow position and disable the axis.
  4. Command the elevation stow pin to extend.
  5. While the elevation stow pin is extending activate the ALL STOP button.
  6. Verify the Elevation Stow Pin Stops.
    • _______(Check)
  7. Command the elevation stow pin to retract.
  8. While the elevation stow pin is retracting activate the ALL STOP button.
  9. Verify the Elevation Stow Pin Stops.
    • _______(Check)

5.9.1.2 Azimuth Wrap Indicator

The azimuth wrap indicator is located on the MAIN CONSOLE above the indicated azimuth position. The GBT is considered to be on the azimuth CW wrap when the azimuth position is greater than 180 degrees +/- 5 degrees. It is considered to be on the CCW wrap when the azimut position is < 180 degrees +/- 5 degrees. The +/- 5 degrees is a window of grace where the azimuth wrap switch and azimuth redundant wrap switch may disagree.
  1. Move the antenna in azimuth from -90 to 190 degrees and verify the azimuth wrap indicator indicates correctly.
    • _______(Check)
  2. Move the antenna back to 170 degrees and verify the wrap indicator indicates correctly.
    • _______(Check)
  3. Move the antenna to 450 degrees and verify the wrap indicator indicates correctly.
    • _______(Check)

5.9.1.3 Elevation Position at Stow Indicator

The elevation stow indicator is located on the MAIN CONSOLE above the indicated elevation position. It should indicate when the elevation axis is aligned with one of the 4 different stow positions. These stow positions are:
  1. Snow Dump or 5.131 +/- 0.1 degrees
  2. Survival or 60.105 +/- 0.1 degrees
  3. Bird Bath or 65.864 +/- 0.1 degrees
  4. Access or 77.850 +/- 0.1 degrees

  1. Move the antenna in elevation from 5 to 80 degrees and verify these indicators appear at the correct positions.
    • _______(Check)

5.9.1.4 Azimuth Lockout

  1. Release all azimuth lockouts and verify no azimuth lockouts are indicated on the Main Console.
  2. Lockout azimuth using the Operator key in the GBT Control room.
  3. Verify the azimuth lockout icon is present on the Main Console and the axis cannot be enabled by the OCU, M&C, MRU or PMU.
    • _______(Check)
  4. Release the lockout in the GBT Control Room and apply the Servo room Operator Key Lockout.
  5. Verify the azimuth lockout icon is present on the Main Console and the axis cannot be enabled.
    • _______(Check)
  6. Release the Servo room Operator lockout and lockout at the Azimuth Lockout / Tagout station.
  7. Verify the azimuth lockout icon is present on the Main Console and the axis cannot be enabled.
    • _______(Check)
  8. Release the Azimuth Lockout / Tagout and lockout at the Azimuth/Elevation Lockout / Tagout station.
  9. Verify the azimuth lockout icon is present on the Main Console and the axis cannot be enabled.
    • _______(Check)

5.9.1.5 Elevation Lockout

  1. Release all elevation lockouts and verify no elevation lockouts are indicated on the Main Console.
  2. Lockout elevation using the Operator key in the GBT Control room.
  3. Verify the elevation lockout icon is present on the Main Console and the axis cannot be enabled by the OCU, M&C, MRU or PMU.
    • _______(Check)
  4. Release the lockout in the GBT Control Room and apply the Servo room Operator Key Lockout.
  5. Verify the elevation lockout icon is present on the Main Console and the axis cannot be enabled.
    • _______(Check)
  6. Release the Servo room Operator lockout and lockout at the Elevation Lockout / Tagout station.
  7. Verify the elevation lockout icon is present on the Main Console and the axis cannot be enabled.
    • _______(Check)
  8. Release the Elevation Lockout / Tagout and lockout at the Azimuth/Elevation Lockout / Tagout station.
  9. Verify the elevation lockout icon is present on the Main Console and the axis cannot be enabled.
    • _______(Check)

5.9.1.6 Azimuth Enabled

  1. Enable the azimuth axis and verify the background for AZIMUTH directly above the indicated azimuth position turns green.
    • _______(Check)
  2. Disable the azimuth axis and verify the green background reverts to the default background for the window.

5.9.1.7 Elevation Enabled

  1. Enable the elevation axis and verify the background for ELEVATION directly above the indicated elevation position turns green.
    • _______(Check)
  2. Disable the elevation axis and verify the green background reverts to the default background for the window.

5.9.1.8 Azimuth Position,Command Position, Position Error, Rate, MAX RATE meters.

  1. Commanding the azimuth axis with the OCU verify POSITION, COMMAND POSITION, Position Error, and RATE are correct.
    • _______(Check)
  2. Verify the MAX RATE is the maximum rate specified by the window you are commanding the axis from.
    • _______(Check)
  3. Commanding the azimuth axis with the M&C verify POSITION, COMMAND POSITION, Position Error, RATE and MAX RATE are correct.
    • _______(Check)

5.9.1.9 Elevation Position,Command Position, Position Error, Rate, MAX RATE meters.

  1. Commanding the elevation axis with the OCU verify POSITION, COMMAND POSITION, Position Error, and RATE are correct.
    • _______(Check)
  2. Verify the MAX RATE is the maximum rate specified by the window you are commanding the axis from.
    • _______(Check)
  3. Commanding the elevation axis with the M&C verify POSITION, COMMAND POSITION, Position Error, RATE and MAX RATE are correct.
    • _______(Check)

5.9.1.10 AZ/EL HALT

The AE Stop disables AZ and EL the drives and sets the brakes after a controlled deceleration. If the elevation stow pin is active it disables it. This action is considered a computer servoed E-STOP.

  1. From the OCU, enable both axes through the Az/El Position Designate window and command both axes to move at full velocity.
    • _______(Check)
  2. While the motors are rotating at full velocity execute the AE Stop from the OCU. Verify that the motors decelerate, the brakes are set and the motor controllers are disabled after the deceleration period.
    • _______(Check)
  3. Move to a valid elevation stow position and disable the axis.
  4. Command the stow pin to insert.
  5. While the pin is inserting activate the AZ/EL HALT button.
  6. Verify the stow pin halts.
    • _______(Check)

5.9.2 CONTROL (AZ/EL CONTROL)

  1. From the OCU click the button "Click to Take OCU Control".
    • Verify you were able to take control of the OCU by noting the OCU CONTROL switches to OCU. ___ (Check)
    • Verify the button "Click to Take CCU" becomes visible under CCU CONTROL. ___ (Check)
  2. Take control of the CCU with the M&C computer.
    • Verify the OCU recognizes M&C has control by noting NRAO M&C is displayed under CCU CONTROL ___ (Check)
  3. Release control of the CCU with M&C
    • Verify the OCU recognizes M&C has released control by noting NONE is displayed under CCU CONTROL ___ (Check)
  4. Click on the button "Click to Take CCU" under the section CCU CONTOL.
    • Verify the OCU obtained control by noting OCU is displayed under CCU CONTROL ___ (Check)
    • Verify the buttons "CCU", "MRU", and "PMU" are now visible under the section Unit In Control of Az/El Axes. ___ (Check)
  5. Click on the button "Click to Release CCU".
    • Verify the message "OCU Relinquishing Control" appears under CCU CONTROL. ___ (Check)
    • Verify the M&C computer can again take control of the CCU. ___ (Check)
    • Verify the OCU recognizes M&C has control by noting NRAO M&C is displayed under CCU CONTROL ___ (Check)
  6. Retake control of the CCU with the OCU.
    • Re-verify the buttons "CCU", "MRU", and "PMU" are now visible under the section Unit In Control of Az/El Axes. ___ (Check)
  7. Click CCU under Unit In Control of Az/El Axes.
    • Verify CCU is displayed under Unit In Control of Az/El Axes ___ (Check).
    • Verify the Enabled light is not on for both the MRU and PMU units ___ (Check).
    • Verify the buttons on the bottom of the Main Console are now visible. ___ (Check)
    • Verify the Az/El Position Designate, Azimuth Presets, and the Elevation Stow Windows all allow the user to command axes movement. ___ (Check)
  8. Enable both azimuth and elevation axes.
    • Verify none of the three buttons "CCU", "MRU", or "PMU" are visible under the section Unit In Control of Az/El Axes. ___ (Check)
  9. Disable both axes.
    • Verify all three buttons "CCU", "MRU", and "PMU" become visible. ___ (Check)
  10. Click on the MRU button.
    • Verify the Unit Selected for Control is MRU. ___ (Check)
    • Verify the "Enabled" light appears on the MRU. ___ (Check)
    • Verify the "Enabled" light is not on for the PMU. ___ (Check)
  11. Take control with the MRU.
    • Verify MRU becomes visible under Unit In Control Of Az/El Axes. ___ (Check)
    • Verify you can enable and move both azimuth and elevation axes. ___ (Check)
  12. Disable both axes.
    • Verify you cannot take control of either axis with the PMU, OCU or M&C.
  13. Turn off the OCU and M&C computers and verify the MRU still has control ___ (Check).
  14. Turn the OCU & M&C computers back on and verify the MRU still has control. ___ (Check)
  15. Retake control of the OCU and CCU with the OCU.
  16. Verify the Unit In Control of the Az/El Axes is still the MRU. ___ (Check)
  17. Release control of the MRU.
    • Verify the Unit In Control of Az/El Axes is NONE. ___ (Check)
  18. Click the PMU button under Unit In Control of Az/El Axes.
  19. Rerun steps 11-19 substituting PMU for MRU and vise-versa, thus testing when the PMU has control. ___ (Check)
  20. Rerun steps 1-20 from the OCT.

5.9.3 AZ/EL POSITION DESIGNATE (COMMAND AZ/EL)

The Azimuth Position Designate window allows the Operator to move the antenna to one of 9 azimuth preset positions with one click.

  1. Click on the Azimuth Preset button on the Main Console.
  2. Click one of the nine preset positions.
    • Verify the azimuth axis enables. ___ (Check)
    • Verify azimuth moves to the correct preset position and properly disables. ___ (Check)
  3. Repeat step 2 for all 9 azimuth preset positions. ___ (Check)
  4. Repeat step 2 for one of the preset positions and change the rate before and during the axis movement.
    • Verify the rate changes to the specified rate. ___ (Check)
  5. Repeat step 2 and exit out of window before the axis gets to the commanded position.
    • Verify the computer servos the axis to a full stop then disables it.
  6. Repeat step 2 and press "DISABLE AZ" before the axis gets to the commanded position.
    • Verify the computer servos the axis to a full stop then disables it.

5.9.4 ELEVATION STOW POSITIONS (ELEVATION STOW)

The Elevation Stow Position window allows the Operator to move the antenna to one of 4 elevation stow positions with one click. This window does not provide access to inserting or retracting the elevation stow pin.

  1. Click on the Elevation Stow button on the Main Console.
  2. Click one of the four stow positions.
    • Verify the elevation axis enables. ___ (Check)
    • Verify the status message "EL STOW ALIGNED" appears as the elevation axis nears the designated position.
    • Verify elevation moves to the correct stow position and properly disables. ___ (Check)
  3. Repeat step 2 for all 4 elevation stow positions. ___ (Check)
  4. Repeat step 2 for one of the stow positions and change the rate before and during the axis movement.
    • Verify the rate changes to the specified rate. ___ (Check)
  5. Repeat step 2 and exit out of window before the axis gets to the commanded position.
    • Verify the computer servos the axis to a full stop then disables it.
  6. Repeat step 2 and press "DISABLE EL" before the axis gets to the commanded position.
    • Verify the computer servos the axis to a full stop then disables it.

5.9.5 ELEVATION STOW / ELEVATION STOW PIN

5.9.5.1 MANUAL STOW (MSU)

The Manual Stow Unit (MSU) provides a backup means of controlling the elevation stow mechanism. Manual stowing will be required if stowing is necessary while the OCU and CCU is inoperative. In this situation, the Manual Rate Unit is used to drive the antenna to the stow position. The stow alignment switch will illuminate the ALIGNED LED on the MSU and signal that the pin can be safely commanded to insert. Additional LEDs on the MSU along with the pin position meter give detailed information regarding the state of the pin.

  1. Verify that power is present at the MSU and it is active.
    • _______(Check)
  2. Drive the Elevation axis with the MRU to a designated stow position. The ALIGNED LED lights to designate that the EL axis is in position.
    • _______(Check)
  3. With the MSU, command the pin to extend. Verify that the EL Stow Extend relay is energized and the pin starts to extend.
    • _______(Check)
  4. Monitor the position of the stow pin with the MSU's pin position meter.
    • _______(Check)
  5. Verify that the RETRACTED LED is off, the EXTENDED LED is on, and the EL FAULT LED on both the MRU and PMU are on.
    • _______(Check)
  6. Verify that the STOWED LED turns on when the stow pin is fully extended. Verify the EL Stow Extend relay turns off and the Stow Pin cannot be extended further.
    • _______(Check)
  7. Command the pin to retract. Verify that the EL Stow Retract Relay energizes, the pin begins to retract, and the STOWED LED turns off.
    • _______(Check)
  8. Verify that the EXTENDED LED turns off and the RETRACTED LED turns on when the pin fully retracts. Verify that the EL Stow Retract Relay turns off and the pin cannot be retracted further.
    • _______(Check)
  9. Disconnect the pin alignment status. Command the pin to extend and verify that it extends without the ALIGNED LED status.
    • _______(Check)
  10. Retract the pin and deactivate the MSU.
    • _______(Check)

5.9.5.2 Computer Stow (OCU/OCT)

The GUI control mechanism and position display for the Elevation Stow Pin is on the Main Console. To keep the operator / user from inadvertently moving the stow pin when we are not in a stow position and or when the elevation axis is enabled, this portion of the display is hidden until it is safe to move the pin.

  1. Move the elevation axis to a non-stow position.
    • Verify the Elevation Stow Pin GUI components on the Main Console are not visible. ___ (Check)
  2. Move the elevation axis to a stow position and disable the axis.
    • Verify the Elevation Stow Pin GUI components on the Main Console are visible. ___ (Check)
  3. Enable the elevation axis with no movement.
    • Verify the Elevation Stow Pin GUI components on the Main Console are not visible. ___ (Check)
  4. Disable the elevation axis at this stow position.
  5. Insert the elevation stow pin.
    • Verify as the pin starts to extend the status message "EL STOW EXTENDED" appears on the Status window.
    • Verify the pin properly inserts and the display represents how far the pin is inserted. ___ (Check)
    • Verify when the pin is fully extended the message "EL STOW EXTENDED" appears on the FAULT window.
  6. From the OCU verify that neither the Az/El Position Designate Window nor the Elevation Stow Window will allow you to command movement of the elevation axis. ___ (Check)
  7. Verify you are free to move the antenna in azimuth from any OCU window. ___ (Check)
  8. Retract the elevation stow pin and verify you can now move the antenna in elevation from either the Elevation Stow window or the Az/El Position Designate window. ___ (Check)

5.9.5.3 Computer Stow (M&C)

  1. Move the elevation axis to a non-stow position.
    • Verify you are not allowed to insert the elevation stow pin. ___ (Check)
  2. Move the elevation axis to a stow position and disable the axis.
    • Verify you are allowed to insert the elevation stow pin. ___ (Check)
  3. Retract the pin and enable the elevation axis with no movement.
    • Verify you are not allowed to insert the elevation stow pin. ___ (Check)
  4. Disable the elevation axis at this stow position.
  5. Insert the elevation stow pin.
    • Verify the pin properly inserts and the display represents how far the pin is inserted. ___ (Check)
  6. Verify you are free to move the antenna in azimuth. ___ (Check)
  7. Retract the elevation stow pin and verify you can now move the antenna in elevation. ___ (Check)

5.9.5.4 Computer Stow (AUTO STOW)

See Section 7. AUTO STOW

5.10 M&C (To Be Designed by Joe/Melinda)

This section reserved for Joe and Melinda to add additional testing they feel is necessary to test additional M&C functionality not covered in Section 5.
  1. CONTROL
  2. ENABLING
  3. MOVING
  4. DISABLING
  5. ELEVATION STOW PIN

5.11 WARNING HORN AND WARNING LIGHT

The warning horn provides a 5 second delay before antenna movement to provide for personnel safety. The warning light is on anytime an axis is enabled. If the warning light is not connected, monitor the AC voltage at K18-4 to K18-5. 120 VAC is present when the light is active.

  1. Take control of the Az/El servo system with the OCU and verify that the warning horn comes on for approximately 5 seconds and then turns off.
    • _______(Check)
  2. Verify that the warning light comes on and stays on when the axis is enabled.
    • _______(Check)
  3. Command an ALL STOP from the OCU. Verify that the warning light turns off as the axes disable.
    • _______(Check)
  4. Enable the MRU through the OCU Control menu. Take control with the MRU. Verify that the warning horn comes on for approximately 5 seconds and then turns off. * _______(Check)
  5. Verify that the warning light comes on and stays on while the axis is enabled.
    • _______(Check)
  6. Disable the MRU. Verify that the warning light turns off.
    • _______(Check)
  7. Release the MRU then enable the PMU from the Control menu. Take control with the PMU. Verify that the warning horn comes on for approximately 5 seconds and then turns off.
    • _______(Check)
  8. Verify that the warning light comes on and stays on while the axis is enabled.
    • _______(Check)
  9. Disable the PMU. Verify that the warning light turns off.
    • _______(Check)
  10. Pass AZ/EL control to the CCU. Verify that the Warning Horn is activated indicating a change of the control state.
    • _______(Check)
  11. From the OCU, pass control of the CCU to the M&C computer and pass control of the OCU to the OCT. Verify that the Warning Horn is activated when the M&C computer takes control.
    • _______(Check)
  12. Enable the axes via the M&C computer.
    • _______(Check)
  13. Verify the warning light comes on and stays on while the axes are enabled.
    • _______(Check)
  14. From the M&C computer, stop the axes and release control of the CCU.
    • _______(Check)
  15. Verify the warning light turns off as the axes disable.
    • _______(Check)

5.12 POSITION ENCODER

The Position Encoder Interface (PEI) is designed to allow the old CCU to read position encoder data while it captures the data and passes it on to the new CCU. While the old CCU is in place it is the unit generating the Clock and Read control signals. The PEI basically just snoops on the data and captures it as it streams by, to the old CCU. When the new CCU has been fully tested and blessed and the old CCU has been taken out of the system then the PEI will generate the Clock and Read control signals to the position encoder.

5.12.1 Position Encoder read by PCD Generated Clocks (THIS SECTION OBSOLETE / DELETED)

5.13 INTERFACE CABINET METERS AND TEST POINTS

This test will demonstrate the capability of the meters and test points to track motor rate over their full range. All test points in the interface cabinet are supported / active whenever the MRU or PMU are in control of the antenna. Only the Rate and Current meters are active when in computer control. This procedure is to test the rate and current meters when the servo system is controlled by the PTCS SRP upgrade system.

5.13.1 Rate Meters and Test Points

5.13.1.1 Rate and Current Meters for Azimuth movement in CW direction.

  1. From the OCU command azimuth to a position 20 degrees away at 1/4 full speed.
    • Verify that the AZ rate meters deflect + ¼ and the associated test points measure 2.5 VDC (+/- 0.3V). ___ (Check)
    • Verify the AZ current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  2. Increase the rate to 50 %.
    • Verify that the AZ rate meters deflect + ½ and the associated test points measure 5.0 VDC (+/- 0.3V). ___ (Check)
    • Verify the AZ current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  3. Increase the rate to 100 %.
    • Verify that the AZ rate meters deflect + full scale and the associated test points measure 10.0 VDC (+/- 0.3V)._______ (Check)
    • Verify the AZ current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. (The motors should be out of torque bias at full speed.) ___ (Check)

5.13.1.2 Rate and Current Meters for Azimuth movement in CCW direction.

  1. From the OCU command azimuth to a position -20 degrees away at 1/4 full speed.
    • Verify that the AZ rate meters deflect + ¼ and the associated test points measure -2.5 VDC (+/- 0.3V). ___ (Check)
    • Verify the AZ current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  2. Increase the rate to -50 %.
    • Verify that the AZ rate meters deflect + ½ and the associated test points measure -5.0 VDC (+/- 0.3V). ___ (Check)
    • Verify the AZ current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  3. Increase the rate to -100 %.
    • Verify that the AZ rate meters deflect + full scale and the associated test points measure -10.0 VDC (+/- 0.3V)._______ (Check)
    • Verify the AZ current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check) (The motors should be out of torque bias at full speed.) ___ (Check)

5.13.1.3 Rate and Current Meters for Elevation movement in UP direction.

  1. From the OCU command elevation to a position 20 degrees away at 1/4 full speed.
    • Verify that the EL rate meters deflect + ¼ and the associated test points measure 2.5 VDC (+/- 0.3V). ___ (Check)
    • Verify the EL current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  2. Increase the rate to 50 %.
    • Verify that the EL rate meters deflect + ½ and the associated test points measure 5.0 VDC (+/- 0.3V). ___ (Check)
    • Verify the EL current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  3. Increase the rate to 100 %.
    • Verify that the EL rate meters deflect + full scale and the associated test points measure 10.0 VDC (+/- 0.3V)._______ (Check)
    • Verify the EL current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)

5.13.1.4 Rate and Current Meters for Elevation movement in down direction.

  1. From the OCU command elevation to a position -20 degrees away at 1/4 full speed.
    • Verify that the EL rate meters deflect + ¼ and the associated test points measure -2.5 VDC (+/- 0.3V). ___ (Check)
    • Verify the EL current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  2. Increase the rate to -50 %.
    • Verify that the EL rate meters deflect + ½ and the associated test points measure -5.0 VDC (+/- 0.3V). ___ (Check)
    • Verify the EL current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)
  3. Increase the rate to -100 %.
    • Verify that the EL rate meters deflect + full scale and the associated test points measure -10.0 VDC (+/- 0.3V)._______ (Check)
    • Verify the EL current meters deflect in the correct direction, due to torque bias pairing, with the correct magnitude. ___ (Check)

7.0 AUTO STOW

This test verifies the proper operation of the stow algorithm for Auto Stow. Using the Servo Monitor log elevation position, rate feedback and current feedback during testing when three phase power removal is substituted with a toggling of the generator switch. All other times record one of the elevation tachometers with an data logger.

Most of the time when the system looses power and we begin auto-stow the operator will only have control of the antenna through the OCT. This is because it is very probable the M&C system has lost power and the Operator is not at the GBT but in the control room. Therefore when you are aborting an auto-stow always test with at least the OCT.

7.0.1 Scenario 1

System on emergency generator power, with Subreflector in use (PFF stowed, deployment boom retracted), and NRAO M&C in sidereal track.

  1. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  2. Verify the horn honks for approximately five seconds and turns off and the warning light comes on as the EL axis enables and drives toward the survival stow position. _______(Check)
  3. Verify the "EL STOW ALIGNED" message appears as the elevation axis reaches position. _______(Check)
  4. Verify that the Azimuth axis does not enable. _______(Check)
  5. Verify the axis disables, the pin extends and the "EL STOW EXTENDED" message appears. _______(Check)
  6. Verify the pin reaches full extension, stops, and the "EL STOWED" message appears. _______(Check)
  7. Verify the subreflector retracts. _______(Check)
  8. Verify that the stowed status relay is activated. _______(Check)
  9. From the OCT control window take control of the CCU with the OCU. _______(Check)
  10. Verify the horn honks, the status message "RELINQUISHING CONTROL CCU" clears and the status message "OCU IN CCU CONTROL" appears. _______(Check)
  11. Acknowledge the "AUTO STOWING" fault and verify the fault message clears. _______(Check)
  12. From the OCT, retract the elevation stow pin. Verify the stow pin retract command is issued and AZ and EL motors remain disabled. _______(Check)
  13. Verify that the elevation and azimuth motors remain disabled and the "EL STOWED" message clears. _______(Check)
  14. Verify that the Stowed Status Relay turns off. _______(Check)
  15. Verify that the message "EL STOW EXTENDED" clears. _______(Check)
  16. Clear the PLC over-ride at input X343.

7.0.2 Scenario 2

Abort auto stow by taking control of the system with the OCU, OCT, or M&C computer.

  1. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  2. Verify the EL axis begins driving to stow. _______(Check)
  3. Take control of the system with the OCU, OCT, or M&C. _______(Check)
  4. Verify the system executes a soft stop when you take control. _______(Check)
  5. Clear the PLC over-ride at input X343.
  6. Repeat steps 1-5 for all three control inputs (M&C, OCU, and OCT).

7.0.3 Scenario 3

Abort auto stow using an Emergency Stop switch.

  1. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  2. Verify the EL axis reaches the Stow Position. _______(Check)
  3. Activate an Emergency Stop switch. _______(Check)
  4. Verify the system immediately stops. _______(Check)
  5. Verify the Elevation Stow Pin does not insert. _______(Check)
  6. Remove the E-Stop and verify all axes remain disabled. _______(Check)
  7. Clear the PLC over-ride at input X343.
  8. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  9. Wait for the EL axis brakes to release.
  10. Activate an Emergency Stop switch immediately after the last brake releases. _______(Check)
  11. Verify the system disables immediately. _______(Check)
  12. Remove the E-Stop and verify all axes remain disabled. _______(Check)
  13. Clear the PLC over-ride at input X343.

7.0.4 Scenario 4

Auto Stow will not operate if the AZ/EL axes are locked out.

  1. Activate AZ/EL movement lock out _______(Check)
  2. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  3. Verify the system tries to command EL to position. _______(Check)
  4. Verify the system does not move. _______(Check)
  5. Remove the AZ/EL movement lockouts. _______(Check)
  6. Verify all axes remain disabled. _______(Check)
  7. Clear the PLC over-ride at input X343.

7.0.5 Scenario 5

The telescope will not unstow if it is stowed in any other position. The PFF axes will be driven to the stow position.

  1. Stow the telescope in a stow position other than survival and pin the Elevation axis. _______(Check)
  2. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  3. Verify the system stows feed arm axes and leaves EL pinned. _______(Check)
  4. Clear the PLC over-ride at input X343.

7.0.6 Scenario 6

The telescope will pin the EL axis if it is positioned at the survival position but not pinned.

  1. Drive the telescope to the survival position without pinning the EL axis._______(Check)
  2. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  3. Verify the system pins the EL axis._______(Check)
  4. Verify the feed arm axes all stow. _______(Check)
  5. Clear the PLC over-ride at input X343.

7.0.7 Scenario 7

System under emergency power while operating from the PMU.

  1. Begin with the PMU in control of azimuth and elevation.
  2. Simulate "Generator Active" by over-riding PLC input X343 and setting it to a "1". _______(Check)
  3. Verify that the telescope does not move. _______(Check)
  4. Verify the PMU remains in control of the antenna. _______(Check)
  5. Release control from the PMU and verify the antenna does not attempt to auto-stow.
  6. Verify you can take control of the antenna with the OCU and command movement._______(Check)
  7. Clear the PLC over-ride at input X343.

7.0.9 Scenario 8

System on emergency generator power, with deployment boom extended and PFF in use, and NRAO M&C in sidereal track.

  1. Remove three phase power to the substation. Verify that the generator comes on line and verify the status messages "GENERATOR", "RELINQUISHING CONTROL CCU" and the fault message "AUTO STOWING" appear. _______(Check)
  2. Verify the generator power signal using DirectSoft and monitoring input X343. _______(Check)
  3. Verify the horn honks for approximately five seconds and turns off and the warning light comes on as the EL axis enables and drives toward the survival stow position. _______(Check)
  4. Record time form Generator Active to El Axis brake release command. _______(Record)
  5. Verify the "EL STOW ALIGNED" message appears as the elevation axis reaches position. _______(Check)
  6. Verify that the Azimuth axis does not enable. _______(Check)
  7. Verify the axis disables, the pin extends and the "EL STOW EXTENDED" message appears. _______(Check)
  8. Verify the pin reaches full extension, stops, and the "EL STOWED" message appears. _______(Check)
  9. Verify the deployment boom retracts. _______(Check)
  10. Verify that the stowed status relay is activated (K25).{This check is not necessary. This relay was originally specified to signal NRAO circuitry when the antenna was auto-stowed so we could automatically switch from the 600KW generator to the 50KW generator. We do not do this. } _______(Check)
  11. Verify the SCU auto-stows the Prime Focus Boom. _______(Check)
  12. From the OCT control window take control of the CCU. _______(Check)
  13. Verify the horn honks, the status message "RELINQUISHING CONTROL CCU" clears and the status message "OCU IN CCU CONTROL" appears. _______(Check)
  14. Acknowledge the "AUTO STOWING" fault and verify the fault message clears. _______(Check)
  15. From the OCT, retract the elevation stow pin. Verify the stow pin retract command is issued and AZ and EL motors remain disabled. _______(Check)
  16. Verify that the elevation and azimuth motors remain disabled and the "EL STOWED" message clears. _______(Check)
  17. Verify that the Stowed Status Relay turns off. _______(Check)
  18. Verify that the message "EL STOW EXTENDED" clears. _______(Check)
  19. From monitoring one of the elevation tachometers, calculate the acceleration during the stowing process for elevation. _______(Record)
  20. Verify that elevation acceleration is 100% (0.1°/s2). _______(Check)
  21. Verify the elevation rate, during AUTO STOW, is 11.8 deg/min. _______(Check)

8. Servo Subsystem Faults

This section verifies the system "Fails Safe" when servo intra-subsystem and inter-subsystem faults occur. Unless specified otherwise, any axis specified to be enabled shall be located a safe distance from the axis limits before any testing is performed. Unless specified otherwise, all axes shall be enabled through the OCU, OCT or M&C computers, not the PMU nor the MRU.

  • Each MCI shares the following links with the PLC:
    • MCI Ready / Fault
    • MCI ON
    • MCI Watchdog
    • MCI Control Select
    • MCI Fwd / RVS Enable
    • MCI Reset
  • The Ready/Fault, ON, and Fwd/RVS Enables are fully tested elsewhere.
  • The MCI Reset is not enabled nor used.
  • The Control Select will be tested under the MCI section below.

8.1.1.3.1 Azimuth MCI Watchdog Failures
  • The purpose of this test is to verify that all MCI watchdog link failures will be properly handled by the PLC. To test every failure permatation is not the intent.
  1. Enable the azimuth axis through the OCU or M&C.
  2. Disconnect azimuth MCI#N watchdog link from the PLC.
  3. Verify the PLC disables that drive and its torque biased pair and the proper faults are displayed on the OCU and M&C systems. _______(Check)
  4. Repeat steps 1-3 for MCI#M, where M is not the torque biased pair of N.
  5. Verify the PLC disables that drive and its torque biased pair and the proper faults are displayed on the OCU and M&C systems. _______(Check)
  6. Repeat steps 1-3 for MCI#P, where P is not the torque biased pair for either N nor M.
  7. Verify the PLC disabled the azimuth axis and the proper faults were displayed. _______(Check)
  8. Replace all MCI watchdog lines then re-enable the azimuth axis. Verify all faults clear. _______(Check)
  9. Run steps 1-7 for N = 1 thru 16.

8.1.1.3.2 Elevation MCI Watchdog Failures
  • The purpose of this test is to verify that all MCI watchdog link failures will be properly handled by the PLC. To test every failure permatation is not the intent.
  1. Enable the elevation axis through the OCU or M&C.
  2. Disconnect elevation MCI#N watchdog link from the PLC.
  3. Verify the PLC disables that drive and its torque biased pair and the proper faults are displayed on the OCU and M&C systems. _______(Check)
  4. Repeat steps 1-3 for MCI#M, where M is not the torque biased pair with N.
  5. Verify the PLC disables the elevation axis and the proper faults are displayed on the OCU and M&C systems. _______(Check)
  6. Replace all MCI watchdog lines, re-enable the elevation axis and verify all faults clear._______(Check)
  7. Run steps 1-6 for N=1 thru 8.
8.1.2 PLC Supply Failures
8.1.2.1 +24 Volt Supply Failures
  1. Enable both azimuth and elevation axes, holding position.
  2. Pull the supply fuse for the azimuth / elevation brake +24 volt supply.
  3. Verify both axes disable immediately and the proper faults are displayed._______(Check)
  4. Replace the fuse, verify all faults clear and the axes remain disabled.
  5. Enable both azimuth and elevation axes, holding position.
  6. Pull the supply fuse for the Status / Limits / Interlock +24 volt supply.
  7. Verify both axes disable immediately and the proper faults (about every fault in the book) are displayed._______(Check)
  8. Replace the fuse, verify all faults clear and the axes remain disabled.
  9. Enable both azimuth and elevation axes, holding position.
  10. Disconnect the +24 volt line from the PLC base modules going to any of the I/O modules.
  11. Verify both axes disable immediately and the proper faults (about every fault in the book) are displayed._______(Check)
  12. Replace the +24 volt line, verify all faults clear and the axes remain disabled.
  13. Repeat steps 9-12 for any other +24 volt base module lines.

8.1.2.2 +15 Volt Supply Failures
  1. Enable both azimuth and elevation axes, holding position.
  2. Pull the supply fuse for the azimuth / elevation status/control boards + 15 volts.
  3. The system shall display the +15 volt supply loss but shall continue to properly function._______(Check)
  4. Replace the fuse and verify the system remains disabled._______(Check)

8.1.2.3 -15 Volt Supply Failures
  1. Enable both azimuth and elevation axes, holding position.
  2. Pull the supply fuse for the azimuth / elevation status/control boards - 15 volts.
  3. The system shall display the -15 volt supply loss but shall continue to properly function._______(Check)
  4. Replace the fuse and verify the system remains disabled._______(Check)

8.1.2.4 +5 Volt Supply Failures
  1. Enable both azimuth and elevation axes, holding position.
  2. Pull the supply fuse for the azimuth / elevation status/control boards + 5 volts.
  3. The system shall display the +5 volt supply loss but shall continue to properly function._______(Check)
  4. Replace the fuse and verify the system remains disabled._______(Check)

8.1.2.5 120 VAC Failure
  1. Enable both azimuth and elevation axes, holding position.
  2. Pull the supply fuse for the azimuth / elevation status/control boards 120 VAC.
  3. The system shall disable immediately. _______(Check)
  4. The OCU and M&C shall indicate the CCU has lost connection with the PLC._______(Check)
  5. Replace the fuse and verify the system remains disabled._______(Check)

8.1.3 PLC - MCI Testing
  • No extra testing is required in this section.

8.2 CCU

CCU Hardware

IRIG Signal Loss
Condition/Test: IRIG signal loss while active

Detected by: CCU

Expected Response: Message indicating signal loss, otherwise normal but unsynchronized operation.

  1. Enable the elevation axis through the OCU or M&C.
  2. Run the following command on the CCU host computer:
    • ntpq -p
           remote           refid      st t when poll reach   delay   offset  jitter
      ==============================================================================
        ...
      *SHM(0)          .SHM.            0 l   42   64  377    0.000   -0.040   0.006
      
  1. Verify there is an asterisk next to SHM, and 'reach' is 377 (similar to the example above). _______(Check)
  2. Disconnect the IRIG signal from the CCU host computer
  3. Verify the message IRIG signal loss appears. Note: The message may take a few minutes to appear, this is normal. _______(Check)
  4. Verify the axes do not disable. _______(Check)
  5. Re-run the command from step 2 a few minutes apart.
  6. Verify that the reach field changes to a value other than 377. _______(Check)
  7. Reconnect the IRIG signal to the CCU host computer.

8.4 PEI

  1. Encoder Failure
  2. PEI - BEI Link Failure
  3. Supply Failures
  4. PEI - CCU Link Failure

8.5 OCU

  1. Loss of OCU power or Ethernet link.
  2. Take control of the OCU and CCU with the Servo room OCU.
  3. Enable both axes and hold position.
  4. Disconnect the Ethernet connection from the OCU.
  5. Verify the CCU disables both axes immediately._______(Check)
  6. Re-connect the Ethernet connection and verify the axes remain disabled. _______(Check)
-- JoeBrandt - 2016-04-12
Topic revision: r6 - 2016-04-14, JoeBrandt
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding NRAO Public Wiki? Send feedback