Subject: cross-microvax calibration veto tested successfully
From: Erik Katsavounidis (Erik.Katsavounidis@lngs.infn.it)
Date: Mon Jan 10 2000 - 09:55:46 EST
Hi all,
Last Wednesday, I looked into the long (>4 year) standing question
regarding the cross-uVax veto for all cross-uV CSPAM/FMT/HIP triggers
during caliruns. I have checked all signal chain for what
concerns the vetoing of SM2/3 triggers in uvax2 when uvax1 is being
calibrated.
First of all, all signals coming in/out of the corresponding SPU and
the involved gate generators were as expected (and of excellent quality
actually). NOtice that the second "CAL" output of the uV1 SPU is send
over a long RD58 cable to uV2 where it goes through a gate generator
before it is sent to the 23VETO input of the uV2 SPU. Incidentally,
the *first* "CAL" output of the uV1 SPU is dead, but this does not
interfere with the functioning of the x-uV veto scheme.
As you know, the input to 23VETO of the uV2 SPU veto'es CSPAM23,HIPT23
and FMT23 (numbers here refer to SM) input for as long as it is active.
After ruling out any cable/module problem, it was obvious that the problem
was related to the width of the signal that goes into the 23VETO input
of the uV2 SPU. I adjusted it to (if I recall well) ~100 microseconds
to find out that the vetoing was working as expected, i.e., while
an LED run was going in uV1 (and thus the CSPAM23 trigger was created and
sent to uV2), I could take normal data on uV2.
We have already scheduled the work of adjusting all gate generators that
control the width of the veto signals that go into the SPUs so that by
next Wednesday the circuitry should be functional detector-wide, thus
allowing us to take calibration data in one uV while taking normal data
in any of the rest.
There are 4 such gate units, 2 in uV2 (one for 23VETO and one for 45VETO),
1 in uV1 (23VETO) and 1 in uV3 (45VETO).
Please in case you decide to collect normal data with a uV while calibrating
another, please include the normal data uV with the PHRASE ones.
A presto,
--Erik
PS: THe RUN with the test data is 91678
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