DAQMB Control Words

  • Conventions:
    • bit 16 is control-word-flag
    • bits 15-13 are control word type identifier bits:
      • 000=Header1(H1), 001=H2, 010=H3, 011=H4, 100=Tail1(T1), 101=T2, 110=AFEB Error?, 111=CFEB Error
    • Headers are sent first, before the data stream for the event
    • Tail words are sent last, after the data stream for the event
    • Remaining 12 bits are available for data
  • Header Word Format:
    • H1 Contains encoded word count:
      • 2bit Evt type(ET):00=Normal, 01=Diagnostic, 10=Synchronization
      • 1bit CLCT(C): 1=Cathode LCT was set
      • 3bit CFEB-LCT count(CC)
      • 1bit ALCT(A)
      • 3bit AFEB-LCT count(AC)
      • WordCount(ET=00)=4*(A+C)+35*AC+776*CC+6(for Header and Tail words)
      • WordCount(ET=01)=4*(A+C)+35*AC+(776+69)*CC+6
        • Note that for Diagnostic events, AC and CC will include every FEB on the chamber!
      • WordCount(ET=10)=4*(A+C)+6?
        • What else is needed during sychronization tests?
    • H2 will contain the L1Acc number (from TMB?)
    • H3 will contain the BXN associated with the L1Acc number (from TMB?)
    • H4 may contain other information:
      • which A/CFEBs were triggered?
      • BXN from A/CLCT cards?
      • BXN from DAQMB at time of LCT?
  • Tail Word Format:
    • T1 is repeat of H1
    • T2 may contain an absolute word count (unencoded)
  • Error Word Format
    • There will be some error type designation depending on the type of error:
      • SCA Overflow
      • DAQMB Internal FIFO Overflow
      • DAQMB External FIFO Overflow
      • Multiple Events overlapping a sample (more than 2)
      • DDU FIFO Full
      • Synchronization error
      • Optical Fiber Transmission Error