PID_FIXCYCLE

Llibrary The library UTIL.Library\ \ provides the following PID_FIXCYCLE controller:

PID_FIXCYCLE in FBD

This function block functionally corresponds to the PID controller with the exception that the cycle time is not measured automatically by an internal function but is set by input CYCLE (in seconds).

Attention

For fast and fix tasks it is recommended to use PID_FIXCYCLE instead of PID, because the cycle time is defined accurately, whereas PID only can measure the cycle time with a maximum accuracy of milliseconds. In case of very short cycles (1ms) this might lead to a rough run (see PID).

Attention

It is not necessary to readjust the controller parameters (KP, TN, TV) if the cycle time changes.