The D_REA function block is used for reaction Diagnostics.

Once the expected reaction has occurred in the Action diagnostics, the reaction diagnostics are checked to ascertain whether the process contains the status.

The process reaction, defined as a term or a signal, is checked through the reaction diagnostics to determine whether the status is stable. During technical processes it can occur that the reactions change momentarily (e.g. hitting limit switches). In order for the reaction diagnostics not to activate the error message ERR directly in such a case, a tolerance time DTIME can be defined. An error signal occurs if this time is exceeded. The error signal becomes inactive when the reaction returns to the setpoint status or when the stop condition is met.

The stop condition terminates reaction diagnostics.

Monitoring is carried out cyclically. The activation of the diagnostics and thereby the distribution of the cycle load can be achieved through the enable signal ED.

EN and ENO can be configured as additional parameters.

CAL D_REA_Instance (ED:=EnableDiagnosis,
    DTIME:=ToleranceTime, REACT:=ReactionSignal,
    STOP:=StopSignal, ERR=>ErrorFlag)

D_REA_Instance (ED:=EnableDiagnosis,
    DTIME:=ToleranceTime, REACT:=ReactionSignal,
    STOP:=StopSignal, ERR=>ErrorFlag) ;