Sheila, Stefan We lost the interferometer a couple of times in TR_CARM, but where able to track it down to a test point data access error (through hcdu.avg). (We used this to zero the offsets for the arms.) For some unexplained reason the test point for LSC-TR_X_QPD_B_SUM_IN1 was returning zero instead of the actual arm power numbers. We verified this with data viewer - but just after we convinced ourself that this problem was real, the data started to flow again. Sure enough the script worked again...