DAQ Testing/20190212

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February 12th, 2019 Testers: Cameron Clarke, Ye Tian


  • Figure out what's up with the new Helicity Control Board Firmware that makes it act differently

Helboard Debugging

Using Bob's TEDf test stand Cameron noticed that the Helicity Control Board that had recently had its firmware upgraded did not work in free-clock mode right off the bat - it is not getting a heartbeat

  • Talk with Roger Flood: he took the board last Friday and re-flashed all of the firmware to make sure it works
    • Cameron tested it again today and found the same problem - took it back to him and he suggests trying to talk with Software EPICs people who know which software bits need to be set in order to turn on and off the Free Clock vs. 30Hz line sync modes
  • Using readHelBoard(bit) doesn't return anything for values other than the 4 main helicity sequence setting bits - go to MCC to ask Kyle Hesse

Kyle Hesse:

  • In EPICs there is setting of a "CLOCK" parameter which can be set to Free Running mode or to several CLOCK locking modes when the ROC is connected to an EPICS IOC
  • Kyle shows the EPICs interface (search for Helicity in JMenu)
    • Sets bits for CLOCK with EPICS from an IOC
    • CLOCK Offset = 0x0f
    • CLOCK Mask = 0xff
    • Bits: 0000 0000
    • 0 = 30 Hz Line Sync
    • 1 = 120 Hz Line Sync
    • 2 = 240 Hz Line Sync
    • 3 = Free Clock (Defaults?)
  • We look at the Injector Crate's Helicity Control Board
    • It has a 30Hz line synch signal plugged into it to trigger off of (unlike the TEDf test stand)
  • Go to UITF VME Test Crate to test one of the new firmware boards that Kyle has in his possession -> Observations:
    • The Helboard will load the software and address and initialize all just fine
    • Giving a 30 Hz line sync fiber signal input (top port) will wake up the board from dormant heart beat (HB light turns on, and so does BS light on the left)
      • This works in either Free Clock or Line Synch mode
    • If we set the CLOCK bit to 240 Hz liny synch mode then it will blink 8 times faster, even if 30 Hz reference is plugged in, meaning the software is speeding up, and the reference clock is just a reference
    • If we switch to free clock mode and then remove the 30 Hz reference fiber the board will still work!
      • But then switching back to 30 Hz line synch mode with the 30 Hz reference removed will go back to dormant hearbeat mode, and switching back to free clock will fail again
  • Conclusion: So in order to get free clock to work you have to initially wake up the HelBoard and get it cycling, and if it goes to sleep it stays asleep until you give it a reference again
  • What about the "old" board that works from boot?
    • Has exactly the same behavior except that it wakes up at boot without needing a reference signal but it still falls dormant and needs to be revived in the same way
  • Goal: we would like to at least preserve the "old" behavior, and we would like to not require a reference signal at all to use the free clock mode