Let me clarify the action taken this afternoon: while we were diagnosing the problem we found that MF4 and 5 were somehow creating the problem, and decided to take them out of the remote control loop. Mainframes 1-3 (beam-beam) and 6 TOFCAL can still be addressed thru BRAHVO. Let me repeat what Flemming said; do not cycle the ac power of mainframes 4 and 5. Another problem appeared around 23:00 and it must have been reported in the shift report; T3 I had a general trip. Anodes trip even with 50 volts. Looks like a short somewhere in that module. While trying to diagnose that problem I was faced again with the fact that BRAHVO cannot reset tripped channels. Is there a procedure to do that? Ramiro On Thu, 20 Sep 2001, it was written: > The Lecroy 4032 system that maintains HV for BB counters, Tiles and the TPC gating grids i.e. all in all > essential parts of the exp. HV went into the mode where it could not be controlled.The L1458 for TPCs, DC and RICH > are all operational. > Bob Scheetz and Ramiro had a controlled access around 6.00pm and decied to put the main frames on local > after Voltages were set to proper value. This mean they cannot be controlled, nor checked by the Brahvo program. > The best we can hope for is that no power surge will appear and bring the PS down. > The task of the shift crew (person) is to check that the detectors respond properly by checking the monitor plots > carefully. Should a drop-out occur we will have to request a controlled access and reset the voltages, until we can > attempt a diagnostic and repair phase. Unfortunately this looks like an intermittent effect, and it may well be that the systems > are back to normal when restored to remote. > DO NOT attempt to cycle power- this will loose settings for sure. > contact Ramiro Debbe/F.Videbaek if system goes back in day-evening hours. At night just stand-by and note failure. > > > > > ------------------------------------------------------ > Flemming Videbaek > Physics Department > Brookhaven National Laboratory > > tlf: 631-344-4106 > fax 631-344-1334 > e-mail: videbaek@bnl.gov >
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