In an effort for robustness we had installed a UPS on the safety system power supply last year to help ride through any minor power bumps.  This morning at 14:34 UTC the UPS failed and took down the lasers that are connected to it.   We probably would not have been down as long but I misinterpreted the error message.   It was a communication error the Term6-Term20.  I took this to mean term 20 which is the TCS CO2 laser interlock had failed.   Sure enough there were no link lights.  Swapped out the module but still not link lights.  So new interpretation is it was terminal through 20 not just 20.  Went to the chassis in the LVEAj and power was off.  The UPS that feeds the 24V power supply was off.  Bypassed the unit for now and the system has been restored.  Since we were down anyway rebooted the computer since it had been running for months.  Reset all the systems and turned on all the lasers that were off. Finishing with EY ALS.

Laser that went down.

TCS CO2-X

TCS CO2-Y

SQZ-

ALS X

ALS Y