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User name Johna
Log entry time 17:30:55 on October28,1999
Entry number 18747
This entry is a followup to: 18562
keyword=SOS TDC back to 100ps/channel.
All of the SOS TDCs had been set to 50ps/channel for Gen. Steve Wood
had already restored the hodoscope TDCs (slots 22 and 20) to 25ps/channel (see
hclog#18562). I have now also restored the other TDC (slot 18, misc. trigger signals) to its original setting of 100ps/channel. While this will have a small effect on the coincidence timing resolution, there were some signals being cut off because of the
reduced full-scale range of the TDC. They may not have been important, but
since the impact on the cointime is minimal (and identical to the HMS version),
we decided to be safe and take the full 400ns range.
It is not possible to put HMSTRIG into one of the SOS high-resolution
TDCs, because the signal will come too late. However, it may be possible to put
an earlier version of the trigger into an empty channel on the high-resolution TDC,
giving us an additional, 25ps/channel, cointime measurement.