If a PLC has a total scan time of 10 ms and has to monitor a signal that _____ then the controller may not detect this change.
A)changes state once in 20 ms
B)is fast
C)is constantly changing
D)changes state twice in 5 ms

Question

Quizplus · Accepted Answer

The PLC with a scan time of 10 ms may not detect changes that occur more frequently than its scan cycle. A signal that changes state twice in 5 ms has a change period of 2.5 ms, which is faster than the PLC's ability to detect, given its 10 ms scan time.

If a PLC Has a Total Scan Time of 10