HV problem solving page
Proposal for HV testing, acceptance and conditioning for the TRT barrel modules at CERN.
The HV tests, along with the tension and gain mapping, will be done to identify which wires need to be replaced. The HV
conditioning will be the very last step and will only serve to identify which wires will need to be
disabled permanently.
The work intended is slightly more involved than what is described in ATL-IT-QP-0078 but it is largely based on it
and on the tests currently done at the production sites. For reference, here are the voltage settings corresponding to
specific gas gains in binary gas (Ar 70%- CO2 30%):
2.5 X 104 @ 1410 V
5.0 X 104 @ 1490 V
1.0 X 105 @ 1580 V
The various acceptance test would be:
Bad wires will be identified, replaced and then the module will be checked again. Once each module has satisfied these conditions, it will be sent for conditioning where 6 or 12 modules will be processed at a time. I foresee the long-term conditioning test with 1 or 2 sectors as follows:
(we'll have to see what is the optimal time duration here once we get more experience).
During the conditioning period, if a wire gives too many trips, it will be
disabled permanently.
After you have rebooted a computer, the HV monitoring program doesn't get a connection to the power supply, the 'Error I' and 'Error V' lights are on. This might be due to the fact, that the PS seems to accept only 5 connections of this type and they are not properly closed if you reboot the computer. To check if this is the reason for the problem, open Start->Programs->CAEN->HV OPC Server Configurator. If the status of the connection to trt-barrel-ps is 'Ko' it is a problem with the TCP/IP connection. Connect to the PS with 'telnet trt-barrel-ps 1527' and check under '-' (the first symbol on the top line) -> 'Sessions' how many TCP/IP connections are open. If there are 5, you have to reboot the PS.
If you reboot a computer that has a TCP/IP connection to the power supply (for LabView monitoring), this connection will not be stopped properly. To avoid this, stop the connection by opening the HV OPC Server Configurator (Start -> Programs -> CAEN -> HV OPC Server Configurator) and removing the entry trt-barrel-ps. After the reboot you have to add the entry (trt-barrel-ps, TCP/IP, IP address 137.138.179.97) again before you can run the LabView monitoring.
I had to do the following:
1- disconnect the CAEN OPC connection 2- reboot the computer 3- reconnect the CAEN OPC connection (see HV manual in documentation) 4- restart HVmon
sort all files in Tripmon directory by date to find out where the output of tripmon may have been written by mistake. We do not understand why this happens, seemingly even after saving the new file name....
I found all computers running HVmon with a Labview error #6: Error 6 occurred at +write file etc. This is because we have run out of disk space on the trtbar account. 0- click on "stop" in the error dialog box 1- move old data files into the "HV data archives" directory: a shortcut is now on all computers. 2- call the helpdesk 78888 and ask for more disk space on the trtbar account. 3- resume all the HVmon programs
If the power supply needs to be rebooted, do the following in the order given below:
1- stop HVmon on all computers (4 HV stations + 2 HV conditioning) 2- stop the running of Tripmon-9-top and Tripmon-9-bottom 3- turn off the voltage on all modules (HV test stations and conditioning)with the PS interface 4- reboot the power supply by turning off the power (turn off the key) then back on after 15 seconds. 5- re-apply the HV on all modules in test station and conditioning 6- restart all HVmon programs and Tripmon-9-bottom and Tripmon-9-top everywhere