camilla.compton@LIGO.ORG - posted 09:47, Wednesday 08 May 2024 - last comment - 10:22, Wednesday 08 May 2024(77711)
Continued troubleshooting awg issues in ITM in-lock charge measurements
Erik, TJ, Camilla. 16:00UTC to 16:45UTC
Continued troubleshooting awg issues in ITM in-lock charge measurements 77059. Erik had new code to monitor awg and we took ESD_EXC_ITMX to COMPLETE with amplitude of excitation 1000 smaller (so it will not effect SQZ data taking).
First time the excitation didn't come though, Erik suggested restarting the GRD code 'guardctrl restart ESD_EXC_ITMX'. After this, it worked fine. Tested with both the production awg (tested on ITMY) and Erik's awg version (tested on ITMX).
Unsure why we didn't have this issue on ETMs. Had to take the nodes back to manged when complete by taking SUS_CHARGE though INIT. Reverted amplitudes to nominal values.
h1susitmx and itmy were restarted on April 9 because of a Dolphin crash see https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=77040
h1susetmy and h1susetmx didn't need to be restarted, so have been running since March 12. I think if a Guardian node opens an excitation on a model that's been restarted, the node must also be restarted.
There's one bit of confusing evidence: Last tuesday the excitation status bit for h1susitmx was set during the charge measurement and cleared after, even though excitation output was zero (see attached image). This is inconsistent with a guardian node merely needing a restart, in which case the excitation bit isn't set. Camilla pointed out that there were other excitations sent during the charge measurement that could explain the status bit.