[Halld-online] problems with DAQ trigger

[Richard Jones]

Hello Sascha,

We are using the readout list that you provided to us for the UConn fiber
tests, and are having problems as soon as the trigger rate gets above the
level of a few kHz.  Below this rate, there are no problems, but as soon as
two triggers come within a few 10's of microseconds apart, the following
message is displayed on the screen where we started up the start_roc script.

faReadBlock: DMA transfer terminated by unknown BUS error (CSR = ...,
xferCount = ...)

This message is repeated many times per second, and the actual rate of
accepted events fluctuates around a few kHz.  When I try to run the
analyzer on this CODA file, it crashes after a few thousand events.

I think there might be a missing busy signal that protects the DAQ from
being overrun by triggers that come at too high a rate.  Our pulser
generates pulses at a fixed rate around 100kHz.  I don't want to slow down
the pulses, but just prevent triggers from interrupting the readout.

Can you help me with this?

-Richard Jones
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