The EY +24VDC power supply which powers the two SUS IO Chassis went offline. The SWWD in turn tripped the SEI DAC drives.

Fil recovered the IO Chassis and we rebooted h1susey and h1susauxey frontends. All came back with no problems and I untripped the SWWD.

Note that h1omcpi, which receives a 16k IPC channel from h1susetmy, started showing a low receive error rate on its h1ioplsc0 64k receivers. Error rate of 1-6 errors per second, occuring every 5 seconds or so.