A PLC is used to count the number of cans traveling by on a conveyor belt in a fish canning factory. An optical proximity switch detects the passage of each can, sending a discrete (on/off) signal to one of the PLC's input channels. The PLC then counts the number of pulses to determine the number of cans that have passed by: 120 VAC Power supply 24 VDC L1 L2/N Gnd TB-23 10 20 39 Processor Input 00 Gm Red Blu Org DC sourcing INO >>> IN1 IN2 IN3 INA IN5 ING INT- Counter reset COM COM Input DC sinking INO >> IN1 IN2 IN3 IN4 INS ING IN7 COM COM TB-20 10 20 30 Output DC sinking VDC OUTO OUT1 OUT2 OUT3 OUT4 OUTS OUT6 OUT7 COM Cable 45 TB-31 O NO Bik Om O |0|||0|||0|||0| Wht DC sinking Red One day the canning line operator tells you the PLC has stopped counting even though cans continue to run past the proximity switch as the conveyor belt moves. Identify what you would do to begin diagnosing this problem, justifying each step you would take.