I tried to restart the standalone and controls pc after the electrical shutdown but could not get any signal in medm.

I found that the timing signal generator was also resetted.

I turned off the standalone PC, recovered the correct timing signal parameters(  as from elog 1537 ie square wave at 65536 Hz, level 2.5 V, offset 1.25 V) then turned on the timing signal once the standalone pc was on.

After that, I could get the usual readout in medm screen so I restored the snapshot that was saved just before the shutdown.