VEGAS Pulsar Project Meeting: 2015 November 23rd 2:00 - 3:00pm ET

Room / Connection Details

  • GB-137 / Soc 280
  • 192.33.117.12##7144
  • 434-817-6443

Housekeeping Details

  • Main wiki page
  • gbsapp Mailing List
  • Location and regular date and time of meeting - agreed weekly on Mondays; GB-137 / Soc-280; 2-3pm ET
  • ETK codes:
    • Electronics: 432510.GB3015
    • Software: 893252.GB3015
    • Science: 432540.GB3015

Resource Allocations

BLOSS, MARTIN ALAN 0.05
BRANDT, JOSEPH JOHN 0.10
CREAGER, RAY 0.65
DEMOREST, PAUL 0.05
RICHMOND-DECKER, JUSTIN 0.20
FORD, JOHN M 0.05
MELLO, MELINDA JANE 0.05
MCCULLOUGH, RANDY L 0.25
RAY, JASON 0.55
PRESTAGE, RICHARD 0.05
LYNCH, Ryan 0.25
VAN TONDER, VEREESE 0.10

Present

  • Marty, Jason, Randy, Ryan, Richard, Justin, Joe, Vereese, Scott, Ray, Paul, John

BOF file status updates

  • c1500x4096 mode
    • Testing with new GTX 980 on srbs-hpc1
      • Completed tests
        • Issue MONITOR to guppi_daq_control - No packet loss
        • Check NETSTAT for Blocked status - Only at start of scan, data loss continues after netstat goes into normal state
        • Check data rate - Same as for other modes (does not depend on bandwidth)
      • Remaining tests
        • Compare child process resource usage for release and GPU transpose versions of guppi_daq (need to compile release version for new cuda architecture)
        • Profile cuda code with nVidia software
  • c1500x0512 mode
    • Remaining work
      • Rebuild with fixes for c1500x4096
        • Randy to try this week, estimates ready by end of this week
      • Astronomical verification
  • c1500x2048 mode
    • Randy is trying to build using the c1500x4096 build as a basis, but the tool set does not seem to be working, and there are many timing issues
    • As this is low priority Randy will focus on rebuilding c1500x0512 mode for BL
  • Fix for nchan calculation in coherent modes
    • Ready to implemented in other modes
  • Bandpass issues in i0800x0064, 0128, 8192
    • Jason tried rebuilding with new libraries but no change
    • Will look into it more this week
  • Duplicated signal in i0800x8192
  • Low bandwidth modes
    • New filter coefficients
    • Spectrum output instead of time series
    • Implement PFB code
    • Could single GPU keep up with coherent dedispersion?

Software

  • Configtool changes
    • Placement of "windows"
      • Each window should be assigned to a separate bank without having to use dictionary format for restfreq keyword
      • Behavior should emulate spectral line modes 1--19
      • Justin ensured that things are running in single-band mode and this appears to work
    • Unit tests passed, ready for sim testing
  • GBT Status shared memory parameters in PSRFITS headers
    • Completed tests
      • Correct keywords appear in vegas/dibas_status
      • PSRFITS headers have correct values
    • Remaining tests
      • Set observer and source and check PSRFITS headers
      • Verify with GBT hardware
  • Switching signal generation
    • Jam session this Wednesday
    • Randy discovered that there are two values of nchan in the designs, one for switching signal generation and one for the rest of the logic
      • Need to test on srbs-hpc1
    • After this, Manager should be ready
      • Will next need to merge with most up-to-date spectral line Manager
      • Talk to Mark about next release and when we want to merge VPM
  • Matrix HPC
    • No updates

GBT testing

  • Focus on switching signal and c1500x0512 this week

Wideband AP

  • Working through an issue with the manufacturer for filters on the circuit board
    • Filters that were included in the quote will not fit on the board
    • Waiting for quote with new filters
    • Will need to check budget and look at scope of what is to be built once quote with filters is received

VEGAS/DIBAS-style backend for FAST

  • Proposal document nearly finalized
  • Remaining work
    • Fully describe software work component
    • Software will work about this sometime soon

Multicasting for spectral line and pulsar modes

  • Added to agenda for tracking
  • Requires modifications to ROACH configuration and net task must bind to a multicast group instead of a specific host
    • All the 10-gig addresses on the ROACH would be multicast groups, and config will be told which to bind to
    • Some changes to net task code (in VEGAS HPC and guppi_daq code) to initialize sockets

AOB

Date / Time of Next Meeting

  • December 7

-- RyanLynch - 2015-11-30
Topic revision: r2 - 2015-11-30, RyanLynch
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