darkhan.tuyenbayev@LIGO.ORG - posted 15:58, Monday 06 June 2016 - last comment - 11:19, Tuesday 07 June 2016(27585)
Photon Calibrators after the power outage
Summary
On Friday, Pcals were turned off for the June 3-5 power outage (LHO alog 27558).
- Today it was verified that PcalX and PcalY settings were restored with the default values stored in the SDF system.
- The PcalX laser was turned on with a switch on the MEDM screen and the power was set to 5.0 V (nominal). Then we closed the OFS loop.
- The PcalY laser switch was also set to ON and laser power was set to 5.0 V (nominal), but the photodetectors' (TxPD, OFS PD and RxPD) readings indicated that the laser was not on. Currently we are investigating the problem, for now the PcalY laser switch was set to OFF.
Details
After finding out that PcalY PDs are not measuring any power I went to the End-Y and checked following:
- all of the power switches on a PcalY modules are set to ON,
- all of the cables are properly connected,
- +12 / -12 V is coming to Pcal laser power cable,
- +24 / -24 V is coming to AOM driver power cable,
- all other power indicator LEDs on the front panels of the modules were on,
- Pcal laser is not on,
- Shutter is not powered (the power indicator LED on the shutter is off).
From this limited information and under the assumption that nothing is broken in the Pcal system, one of possible sources of the issue might be that control signals are not reaching the Pcal Interface module through an EtherCAT connector. The laser on/off and power level (5.0 V) signals should come through this interface (the Pcal Interface Chassis back-side board circuit is given in D1400149).
The issue in currently under investigation.
Filed FRS 5651
Filiberto, Darkhan,
Summary
Details
As it was reported in the original report above, there was an issue with turning on the PcalY laser and operating the shutter. The issue was discovered yesterday around 11am. After that I came back to get breaker circuits to proceed with investigations, but I found out that it is not needed.
At End Y there were issues with Beckoff system that were discovered independent from Pcal work. The Beckoff system feeds control signals to Pcal through EtherCAT cable into Pcal Interface Module. In the afternoon Filiberto went to EndY and replaced couple interface boards of the Beckoff system (see LHO alog 27583). After he let me know about the replacement work, I went back to EndY to turn on PcalY (needed to switch shutter control back to "remote" and double-check power switches on Pcal modules). Now the issue is resolved and PcalY is operating in its nominal configuration.