After an unlock, corrupted signals were sent by LSC to PR, BS, NI and WI (see figure) mirror DSPs on every relock try. We solved the issue by restarting LSC_Acl process. Relocking is now in progress.
The problem is more widespread, and it is related to the GPS issue some Acl servers have been suffering lately; the processes were stuck logging the same sequence each second (see attachment) and not receiving any command.
I restarted SSFS_Ctrl, ASC_Acl, SNEB_Photodiodes, SWEB_Photodiodes, SDB1_OMC, ISYS_Acl; after the restart the issue was not present anymore.
The ITF was locked again in LOW_NOISE_3.
Side notes:
- since before the beginning of the run the sidebands power SPRB_B4_112MHz_mag is much lower (~60%) than before (see figure), but the stability of the alignment loops is the same, so the other signals, so its seems just rescaled; this seems to have happened after a restart of the SPRB_Photodiodes process on Friday afternoon;
- i found that the dampers MIR_Z_ON are off on both the NI and WI mirrors, I don't remember if this is expected; the North Cavity in particular is moving quite a lot after an unlock.
