Issues reported with the ALS and PCAL lasers at EX, alog 71257. Found the TwinSAFE EL2904 terminal flashing with an error code (10 flashes, Error in output circuit). Online Beckhoff documentation states to power cycle terminal to clear error. Safety chassis power cycled. Error code on terminal did not clear. Unit replaced.
Once terminal was replaced, we noted that we had no communication link lights from the corner station. Network LED on coupler EK1501-0010 was on but very dim. This caused communication errors. Power cycled chassis, no improvement. Coupler was replaced.
Recovery of the access system was delayed due to an outdated MEDM screen, see alog 71271 for details. System recovered and lasers powered back on.
Safety System Controls Chassis - D1600176
Serial Number: S1610447
F. Clara, F. Mera, R. McCarthy, O. Patane, T. Shaffer, and P. Thomas
Total Observing time that was lost was 8 hours, from 17:25 to 01:04 UTC (next day in UTC, 18:04PDT). Five of those hours were troubleshooting and correcting the issue (17:25 - 22:30), while the last three hours were locking the detector, where we lost lock on our way up three different times and needed to run an initial alignment before arriving at NLN at 1:04. Updated the FRS