A machine stops running. The HMI shows no faults. The tech connects a laptop to the PLC and sees the main sequencer rung is false because a proximity switch input is flickering rapidly. What is the mechanical cause?
Answers
AThe HMI has lost communication
BThe proximity switch is mounted too far from the target or is vibrating loose
CThe PLC scan time is too fast
DThe power supply is outputting 120VAC instead of 24VDC
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