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

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