I sent Gautam instructions to first try stopping the modbus service, power cycling the Acromag chassis, then restarting the service. I've seen the Acromags go into an unresponsive state after a strong electrical transient or shorted signal wires, and the unit has to be power cycled to be reset.
If this doesn't resolve it, I'll come in tomorrow to help with the Acromag replacement. We have plenty of spares.
One of the XT1111 units (XT1111a) in the new vacuum system has malfunctioned. So all valves are closed, PSL shutter is also closed, until this is resolved.