Issue
Enclosure Shutter barcode reader 1 or 2 indicate a communication fault in the Alarm log or on the Altitude Status page.
Background
Altitude position is sensed by 2 barcode readers / position encoders.
56WCS1
57WCS2
Wiring details are shown on Enclosure drawings, Cabinet 509, sheets 56, 57
Both encoders are powered through circuit breaker 20QF4 in Cabinet 509
Encoder output is Ethernet connected to network switch 55SU1
Cabinet 304: 10.2.9.173
Cabinet 305: 10.2.9.174
Occasionally either barcode reader communication will stop.
A faulted module will have a slightly different flash sequence.
Connection:
Corrective Action
Cycle power to the modules: Open then close circuit breaker 20QF4
Wait for the modules to power up and begin communicating.
Longer term:
Add a reset relay connected to a PLC output
Connect the relay to circuit breaker m20QF4