Sitting in the control room I heard something about a lock loss. I looked at the monitor that displays various cavity
transmissions and noticed that the laser had tripped. I went into the diode room. The Beckhoff computer indicated
that the laser switched off due to the power watchdog being kicked.
The power watchdog performed as it should.
However we should make it routine to reset the power watchdog every maintenance day. Something we have mentioned
but perhaps were not as diligent about it as we should be.
All the PSL related servos were up by the time I returned to the control room.
Attached is a plot of the laser power since the last time (I believe) the watchdog was reset back on
Sept. 1st.
Images attached to this comment
nutsinee.kijbunchoo@LIGO.ORG - 11:52, Monday 28 September 2015 (22025)
Locked again at NOMINAL_LOW_NOISE. RF45 MODE reduced to 22.2 dB after it was reset to 23.2 by Guardian after the lockloss. Currently not Observing due to Praxxair (a really big truck) on site.
peter.king@LIGO.ORG - 13:08, Monday 28 September 2015 (22029)
When the laser was restarted the main screen indicated that the laser power was 34.7 W. Instead of turning
on the watchdog there and then I decided to wait and let the power stabilise out before setting the dog loose.
Turned on the watchdog at ~13:05 UTC, the power indicated on the screen was 34.1 W.
Sitting in the control room I heard something about a lock loss. I looked at the monitor that displays various cavity transmissions and noticed that the laser had tripped. I went into the diode room. The Beckhoff computer indicated that the laser switched off due to the power watchdog being kicked. The power watchdog performed as it should. However we should make it routine to reset the power watchdog every maintenance day. Something we have mentioned but perhaps were not as diligent about it as we should be. All the PSL related servos were up by the time I returned to the control room. Attached is a plot of the laser power since the last time (I believe) the watchdog was reset back on Sept. 1st.Locked again at NOMINAL_LOW_NOISE. RF45 MODE reduced to 22.2 dB after it was reset to 23.2 by Guardian after the lockloss. Currently not Observing due to Praxxair (a really big truck) on site.