[Halld-online] Alarm values for CDC

[Fernando J Barbosa]

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
>
>
> --
> Michael Staib
> Graduate Student, Dept. of Physics
> Carnegie Mellon University
> mstaib at cmu.edu <mailto:mstaib at cmu.edu>
> phone: 412-268-2983
>
>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/halld-online/attachments/20160412/de658d2a/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 204430 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/halld-online/attachments/20160412/de658d2a/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: barbosa.vcf
Type: text/x-vcard
Size: 265 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/halld-online/attachments/20160412/de658d2a/attachment-0001.vcf>