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User name Lingyan
Log entry time 00:12:01 on February 1,2001
Entry number 56214
keyword=reason of decoder error: VDC threhold zero
We met the following error message when we tried to replay data in the afternoon.
RAWDATA_TIL_EOF:error in EVENT_DECODER
PROCESS_DATA: Error in the EVENT decoding
Bob found out what the decoder complaint was 0x9efe0007 which was telling us channel 127 of slot 19 (model 1877) got a hit, which is impossible
because there are only 96 channels.
And he found that the L-arm fastbus crate was producing events which were 10 times normal size.
The reason turned out to be that the L-arm VDC thresholds were dropped to zero.
Before run 1609, I set them to be 4.10, the same as the R-arm for the moment. We may need to adjust them in the future. I noticed John Lerose adjusted them from 4.0 to 3.5 recently.
By the way, we can't even take cosmic run in buffered mode(twospec), which leads to 100% dead time. In unbuffered mode, the dead time is 0%.