ElliK, NutsineeK, RickS

Looking at the CDS snapshots of PSL screens from home this morning, we realized that the laser had shut down.

As-found control room screens are shown in the snapshot below.

Epics channel trends indicate that the Beckhoff interlock (IL) transitioned about 6 hours ago, but none of the recorded inputs (including the chiller flow inputs) triggered (see trend plot below).

The External Shutter had not tripped on the PSL_laser.adl screen, and the chillers were still running.

In the Diode Room, the Status screen showed ony the "Interlock OK" field red, everything else under interlock green.

Because we had no indication that the source of the fault was the Diode Chiller Flow, I decided not to swap the Diode and Crystal chiller interlock cables.

We had some issues getting the system back on-line, apparently due to accidentally closing a screen on the Beckhoff computer.  Eventually, we rebooted the computer and restarted the PSL software.