Gautam and Steve,
The medm monitor & vac control screens were totally blank since ~ May 24, 2017 Experienced vacuum knowledge is required for this job.
IDENTIFY valve configuration:
How to confirm valve configuration when all vac mons are blank? Each valve has a manual-mechanical position indicator. Look at pressure readings and turbo pump controllers. VAC NORMAL configuration was confirmed based on these information.
Preparation: disconnect valves ( disconnect meaning: valve closes and stays paralized ) in this sequence VC2, VC1 power, VA6, V5, V4 & V1 power, at ifo pressure 7.3E-6 Torr-it ( it = InstruTech cold cathode gauge )
This gauge is independent from all other rack mounted instrumentation and it is still not logged.
Switching to this valve configuration with disconnected valves will insure NOT venting of the vacuum envelope by accidental glitching voltage drop or computer malfunction.
RESET v1Vac1 .........in 2-3 minutes........ ( v1Vac1 - 2 ) the vac control screen started reading pressures & position
Connected cables to valves (meaning: valve will open if it was open before it was disconnected and it will be control able from computer ) in the following order: V4, V1 power, V5, VA6, VC2 & VC1 power, at ifo 2E-5 Torr-it.....
....vac configuration is reading VAC NORMAL,
ifo 7.4E-6 Torr-it
We have to hook up the it-cold cathode gauge to be monitored - logged ! this should be the substitute for the out of order CC1 pressure gauge. |