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User name mercado
Log entry time 15:20:57 on August31,2009
Entry number 287240
keyword=Another HAPPEX DAQ Change
This morning right before the access ended, I was able to go into the Hall and
switch out the 18bit ADC (adcx5), which was showing weird csr values. I put in
place another 18 bit ADC (adcx6), which has a comparable channel range.
As part of this change, ADC channel adcx6_0 started saturating in the negative
again when the detector cable is connected. To remedy this, I changed the
on-board offset DAC for that channel, and the signal went from ~-15000
(negative saturation) to ~400 channels.
I did this by going to the file ~/dev_luis/config/ped_adcx6.txt
and changing the last parameter of the first line. This value determines the
pedestal offset for that channel at gain=(3,0).
The value was changed from 1746 to 600.
A similar change was made for adcx5 on 8/30/09.
The value was changed from 1979 to 1000.