J Kissel, N. Lecoeuche
While glancing at the PCAL END station overview screens, we noticed that the PCALX screen words "STATUS" and "Pcal modules are not powered" were blinking rapidly. The channels that this status indicator are measuring are:
"Pcal modules are not powered"
H1:CAL-PCALX_LASERENABLE
H1:CAL-PCALX_LASERPOWERCONTROL
H1:CAL-PCALX_SHUTTERSTATUS
H1:CAL-PCALX_LASERDIODECURRENT
"STATUS"
H1:CAL-PCALX_TRANSMITTERMODULETEMPERATURE
H1:CAL-PCALX_RECEIVERMODULETEMPERATURE
While the "Pcal modules are not powered" channels are flat and unchanging -- and the same as PCALY -- we found that the "STATUS" channels, i.e. the temperature sensor channels, were reporting a wildly oscillating temperature from 0 to 20 deg Celsius, with a ~1 sec period.
This junk has apparently been happening since Sunday Nov 11 2018 (~a month ago) at 23:38:56 UTC (Nov 11 2018 15:38:56 PST).
Attached are screenshots of when the failure happened, and how the sensor outputs currently look.
Opened FRS-11921
This is a known issue. The parts have been ordered to fix this. I will mark FRS as duplicate. It is in the chassis not the readback chain.
https://services.ligo-la.caltech.edu/FRS/show_bug.cgi?id=10987