HV HowTo for Users
High Voltage Instructions -- the basics
The High Voltage is controlled by LeCroy 1458 crates and associated modules like the 1461N. A trailing "N" means negative, and a "P" means positive HV.
Simplified Instructions : To control the HV in Hall A, do the following
Login as "adev" on the "adaql1" or "adaql2" computers.
cd ~adev/slowc
To run the Left HRS alone: ./hvs LEFT
To run the Right HRS alone: ./hvs RIGHT
To run the beamline crate: ./hvs BEAMLINE
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I haven't gotten around to adaping this yet, but here are some old but useful instructions
http://hallaweb.jlab.org/equipment/daq/HVhelp.html
http://hallaweb.jlab.org/equipment/daq/gen_slow_control.html
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Troubleshooting
A number of things can go wrong. If these solutions don't work for you, call an expert.
1. HV is slow ! Sorry, as I write this (Jan 2014), it's a problem. See point 5, too.
2. HV crate is on ? There are two power supplies which must be turned on.
3. If multiple cards seem "bad" (leading to symptom 5), I've found that power-cycling the HV crate helps !
4. The Java GUI cannnot connect to the server. Note, the server runs on a PC and talks to the HV crate via a serial connection. If the server isn't working for some reason, rebooting the PC may help. The name of the PC is discovered in the tab corresponding to that crate; e.g. intelha3 on Left HRS.
5. Suppose the GUI appears to connect but the pages are incomplete or partially blank or there is a Java exception. I've noticed this when the delay parameters in the server are too small. Not sure what is happening, but I think that in this case the data are sometimes corrupted or incomplete, and the Java GUI cannot handle it. This is related to the problem mentioned in #1. See also 5.
6. Another reason for #5 is that a card may be bad or seems bad. The solution is to run low-level diagnostics, find the card that does not talk, and replace it (but power-cycling can help, see point 3).
