[Halld-online] Alarm values for CDC

[Curtis A. Meyer]

I assume that we would want similar alarms on the FDC as well (assuming that they
are not already there).

Curtis
---------
Curtis A. Meyer			MCS Associate Dean for Faculty and Graduate Affairs
Wean:    (412) 268-2745	Professor of Physics
Doherty: (412) 268-3090	Carnegie Mellon University
Fax:         (412) 681-0648	Pittsburgh, PA 15213
curtis.meyer at cmu.edu	http://www.curtismeyer.com/



> On Apr 12, 2016, at 12:03 PM, Fernando J Barbosa <barbosa at jlab.org> wrote:
> 
> Hi Michael,
> 
> I just have a comment on your last paragraph:
> 
> 
> On 4/12/2016 11:31 AM, Michael Staib wrote:
>> Hi Hovanes,
>> 
>> 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. 
>> 
>> 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.
>> 
>> 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.
> 
> 
> 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.
> 
> Best regards,
> Fernando
> 
> 
> 
>> 
>> Thanks,
>> Mike
>> 
>> <Mail Attachment.png>
>> --
>> Michael Staib
>> Graduate Student, Dept. of Physics
>> Carnegie Mellon University
>> mstaib at cmu.edu <mailto:mstaib at cmu.edu>
>> phone: 412-268-2983
>> 
>> 
>> 
> 
> <barbosa.vcf>

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