FB_BA_ATrigCOV

The function block monitors the value xValue for changes (Change of Value).

The monitored value is independent of the data type (ANY). For reasons of performance, however, only data types smaller than or equal to 4 bytes are supported!

VAR_INPUT

xValue      : ANY;
bForce      : BOOL;

xValue: Value to be monitored.

bForce: Forces a positive comparison ("bQ=TRUE").

VAR_OUTPUT

bReady     : BOOL;
bQ         : BOOL;

bReady: Indicates operability:

If xValue is valid.
Correct value assignment and observance of the permissible data type size.

Memory is initialized.
The comparison can be made at the earliest after one cycle, as the internal memory first has to be initialized with the value xValue.

bQ: Result of the last comparison (TRUE if the value has changed).

Requirements