Subject: SM1 Stop Master
Nicola.Zaccheo@lngs.infn.it
Date: Fri Nov 05 1999 - 04:26:48 EST
Ciao a tutti,
5 months ago (8-Jun-99), starting from run 17740, we replaced the
STPM module on SM1 (that gave a lot of no Q responses) with the
spare one. This last one had two old problems (as, at that time,
Chris Orth remembered to us):
a stuck (always zero) Center face bit in CIT trigger pattern
and "fake" latches on CIT West face.
Last week end (when he was on shift) Yiannis noticed that the fake
hits + bitfound for West CIT were equal to the timeword found for
Center face. So he suspected an error on wiring inside the module!!
Yesterday, "special" maintenance day, Massimo and I checked
this STPM and we found the CAMAC read line for the Center face (R2)
DISCONNECTED from the ACTEL chip # 2. This line should be connected
to pin 42 of the ACTEL. Instead pin 42 was connected to the CAMAC
read line FOR THE WEST face (that should be connected to pin 40;this
pin was not used)!!
Yiannis was right (I had no doubts)!!
We restored everything and the module is working properly now!
In addition, I tested this module with different triggers and
computer busy signals combinations and, once more, I didn't
find any strangeness.
A presto,
Nicola
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