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<div class="moz-cite-prefix">Hi Michael,<br>
<br>
I just have a comment on your last paragraph:<br>
<br>
<br>
On 4/12/2016 11:31 AM, Michael Staib wrote:<br>
</div>
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cite="mid:404F0E37-7A6E-4784-BA6B-C55434087BA7@andrew.cmu.edu"
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Hi Hovanes,
<div class=""><br class="">
</div>
<div class="">I propose the following for low current alarm values
for the CDC. Each preamp card should be drawing 0.45 A of
current. On all channels there are 8 preamp cards connected with
the exception of CDC:lv:Gr19 (4 cards) and CDC:lv:Gr20 (1 card).
Current draw of less than 0.44 Amps per card probably is the
limit we should set. </div>
<div class=""><br class="">
</div>
<div class="">I would propose a major alarm if the current drops
below 3.52A with low voltage on for Gr1-Gr18, 1.76 for Gr19, and
0.44 for Gr20. These thresholds are rather tight, but will cover
the case of a fully disconnected card as well as the case of too
low a gain on the preamp.</div>
<div class=""><br class="">
</div>
<div class="">Note that with this limit, CDC:lv:Gr20 would
currently be in an alarm state. Naomi has noted previously that
the gain on the one card connected to this channel looks
suspiciously low. The voltage needs to be slightly increased
here once the CDC is back online to bring the preamp gain in
line with the other channels.</div>
</blockquote>
<br>
<br>
The current shown for this preamp is shown to be 0.428 A, which is
about right. You may try increasing the voltage a bit so the current
is similar to the other preamps or 0.45A. While dong this, please
monitor the gain via the built-in pulser to be sure it has leveled.<br>
<br>
Best regards,<br>
Fernando<br>
<br>
<br>
<br>
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cite="mid:404F0E37-7A6E-4784-BA6B-C55434087BA7@andrew.cmu.edu"
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<div class="">Thanks,</div>
<div class="">Mike</div>
<div class=""><br class="">
</div>
<div class=""><img apple-width="yes" apple-height="yes"
apple-inline="yes" id="19D44CF2-0133-41E1-A72D-F8357D614D93"
src="cid:part1.04060607.03010809@jlab.org" class=""
height="480" width="594"><br class="">
<div class="">
<div class="">
<div class="">--</div>
<div class="">Michael Staib</div>
<div class="">Graduate Student, Dept. of Physics</div>
<div class="">Carnegie Mellon University</div>
<div class=""><a moz-do-not-send="true"
href="mailto:mstaib@cmu.edu" class="">mstaib@cmu.edu</a></div>
<div class="">phone: 412-268-2983</div>
</div>
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<br class="">
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