elenna.capote@LIGO.ORG - posted 21:02, Tuesday 03 June 2025 (84782)
False WFS DC railed Warning
Oli, Elenna
Oli and I were just baffled as we were stuck in the DRMI acquisition with ISC_DRMI throwing a warning that "WFS DC centering railed", but of course, nothing looked railed at all. We eventually lost lock just sitting there.
I found that ISC_DRMI runs:
DRMI_WFS_CENTERING = ISC_GEN_STATES.gen_WFS_DC_CENTERING('DRMI','REFL_AS_POP')which checks
WFS_DC_centering_servos_OK(port)and the check is:
for py in ['P', 'Y']:
for servo in servos:
if (abs(ezca['ASC-DC%s_%s_OUTPUT' % (servo, py)]) >= ezca['ASC-DC%s_%s_LIMIT' % (servo, py)]):
okayFlag = False
but then I checked DC6 and the limit is zero, so of course this function will report that the centering is railed even when it is not. It appears that the DC 1 and 2 centering loops have limits of 555, and since PM1 the same suspension type as the RMs, I have updated DC6 to have these same limits.
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