Problem: Beam operation in SASE2 is prohibited by SEPS / MPS
Origin of problem: HED-CRL3
(this was already an issue during the past weekend)

HED (Karen) today realigned CRL3 and brought the lenses into the safe OUT state, see entry https://in.xfel.eu/elog/OPERATION-2023/2
In karabo then everything seemed find, SEPS switches all green / OUT, see ATT#1.
Nevertheless, in DOOCS the signal safety_HED_CRL_OPT was still red, see ATT#2.

The MPS safety_HED_CRL_OPT signal from the Beckhoff HED PLC was missing.
Onsite investigation by EEE (Leandro and Bernard) revealed that the Beckhoff crate BKF000476 was offline (switched off).
Switching the crate ON fixed the missing signal problem.

Presumably crate BKF00476 was not powered back on since after the planned power-cut in December 2022,
and because it is not part of PLC EtherCAT loop, the Nagios system didn't inform EEE about the crate status.

Result: Problem solved, beam operation in SASE2 can resume normally.