How does a PLC count the turn-on time of a switch?
A counter that is cycled in OB38 is triggered after turning on. And can do cascade counter to count its expansion. And then multiplied on the line. And can be calculated directly out of the time.
Can be interrupted in the cpu cycle time statistics
But note that the preparation of the time must first clear the concept of the scan cycle, otherwise it is likely that you catch the value of 0 Oh
If you count the accuracy of the time is not very high, that is, the deviation does not matter in 0.1 seconds, then you can add a time relay inside the program, switch ON ON T start timing, switch OFF before a cycle of T The current accumulated value is stored in the other registers, which can be achieved, and can also be stored in different regions for each period of time for long-term observation.
