#55 ADC thresholds not consistently loaded
We noticed that Jam doesn't load ADC thresholds consistently.
Software thresholds are set for each ADC channel in our sort routine, for example:
idGe = vmeMap.eventParameter(3, ADC_BASE_First, 0, GeADC_THRESHOLDS);
where:
static final int GeADC_THRESHOLDS = 25;
We found that when initializing a large number of ADC channels (as in the case of
APEX, 48), at least 3 ADC channels will ignore their threshold completely - like
they weren't even set. This could be a problem when matching the 16 NaI
annulus segments to Chris's Geant simulatations.
We noticed this problem in v.17. Perhaps the problem is not a
specific Jam bug but rather a communication problem with the ADC card. We don't understand why the ADC thresholds are read
in for some channels and not others, and it appears random which channels
cooperate and which do not. What makes it worse is that the pattern is not
reproducible when a the same sort routine is reloaded."
sort routine
I will verify that Jam sends the correct packet(s) for communicating to the front end the desired thresholds. If not, then it is a 'jam' bug. If so, it is an issue in the communications or in the VME rack (possibly controller software needs to verify threshold settings after setting them).