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User name Olivier
Log entry time 19:19:17 on November11,2000
Entry number 51891
keyword=Calo HV trip
HV of calo has tripped. Thanks to Mark's script, it has been discovered right away and no time was lost. Here is the scenario that happened, and here is how to react in case that happens again:
A alarm beaps off on the computer you usually enter official stuff about the shift (beam time table, ...). There is a script continuously running, checking that the scalers are counting at a normal rate. This is the script that triggers the alarm. Look for the window where that script is running. If the alarm indeed comes from here, there should be a repeated message "leadglass rate low".
Check the scalers on the scaler computer (adaqs3 monitor, above the one that runs dhist). There is a window open on e99007-calorimeter scalers. If the scalers read flat 0, there is a very high probability that the HV tripped. Here is how to turn it back on:
On the right-most computer, go in the work-space Portservers. There is a window called :e99007 Leadglass Wall HV. The connection is probably screwed (because of the crate shut off).
Exit the window by typing "Ctrl+]", and "q" at the telnet prompt.
Then connect back by typing "telnet hatsv8 2004" ,
type"1450" at the prompt,
then "vt100" at the next prompt.
What appears now are the HV of the calorimeter. On the upper right corner, there is a "HV OFF" sign. Turn it on by typing "{" (without the " of course). Here it is ! As the HV comes up, you should see the scalers starting counting again. If not, call me !
Now it might happen that the script triggers the alarm, because the beam went away, or for any other reason that you can imagine with computers. If the HV are OK, then kill the script and start it again.