if there is a POU(PLC_PRG) is running on a controller, how to determine the cycle time of a POU? Some of the controllers has returned in the datasheet that about 1000 statement in 3ms. but i just want to know how much time has been taken for a cycle time in a POU? Please advise.

Function TIME() returns the CPU time stamp. Call it on POU entry, store the result in a local variable, then call it before exiting the POU again. The difference to first call ist the execution time of this POU:

VAR
  EntryTmStmp: TIME;
  ExecutionTime: TIME;
END_VAR
EntryTmStmp := TIME();
... (* the contents of your POU here *)
ExecutionTime := TIME() - EntryTmStmp;

In the same way you can check the task cycle.

Thank you for your valuable information. by the way what do you mean the task cycle? Do you mean I can check the task cycle of that particular POU in the codesys software?

Rolf_Geisler hat geschrieben:
Function TIME() returns the CPU time stamp. Call it on POU entry, store the result in a local variable, then call it before exiting the POU again. The difference to first call ist the execution time of this POU:

VAR
  EntryTmStmp: TIME;
  ExecutionTime: TIME;
END_VAR
EntryTmStmp := TIME();
... (* the contents of your POU here *)
ExecutionTime := TIME() - EntryTmStmp;

In the same way you can check the task cycle.

Thank you for your valuable information. by the way what do you mean the task cycle? Do you mean I can check the task cycle of that particular POU in the codesys software?

Hi,

the little exampe I gave shows how to find the execution time of a POU (i.ethe time between starting it's execution and it's end).

The "task cycle" is the time between two consecutive calls of a POU. Sometimes it is useful to know it, particularly in multitasking applications. The way to calculate is similar to the POU execution time:

VAR
  EntryTmStmp: TIME;
  ExecutionTime: TIME;
  TaskCycle: TIME;
END_VAR
TaskCycle := TIME() - EntryTimeStmp;
EntryTmStmp := TIME();
... (* the contents of your POU here *)
ExecutionTime := TIME() - EntryTmStmp;

Hope this makes it clear.

Regards