WP 11799. Patrick T., Ryan S. The PSL Beckhoff PLC has been updated to match the changes made at LLO to add a watchdog channel. This is the code from 'TwinCAT Projekt_LIGO_240124.zip' in https://dcc.ligo.org/E2100235. The now running version is in git at https://git.ligo.org/cds/ifo/beckhoff/lho-psl and commit 9b6ad86cb26660b136242b334bd4831a683f1c5b. It appears there was also a change to fix a bug where toggling the noise eater tripped the NPRO. Ryan verified that this now appears to be fixed. I also removed the ${IFO}.PSL.LASER.MAIN.SHUTTER alias of the bEnable_Shutter2 variable, which according to LLO is not being used. The channel was not being exported to EPICS. There were two minor issues. The first was that the version of a couple of the terminals found from a scan of the EtherCAT bus did not match what was in the IO configuration, and this appeared to be the cause of an INIT error for a couple of terminals (presumably those) when the system was put into run mode. This was fixed by changing the IO configured versions to match the scanned versions. The other was that I forgot to comment out the inversion of the signal from laser PD1, which was not realized until we started everything and were wondering why the power was reading as negative for that PD. I fixed that in a new commit and restarted the code again.
The new pump diode watchdog will trip off the system in the event any of the diodes drops below a set percentage, much like the already existing watchdogs on the output of the NPRO and both amplifiers. I've set this trip level at 80% and enabled the WD. I also added an indicator to the PSL overview medm screen showing the WD is enabled (H1:PSL-LASER_PDWD).