Chapter 11 Function Block Diagram 11.2.4 Inverse Logic Users can insert inverse logic into a Boolean position in a function block diagram, e.g. an input node which represents a Boolean device or a symbol whose data type is BOOL, an output node which represents a Boolean device or a symbol whose data type is BOOL, the En pin of a function block, or the En pint of an applied instruction. However, users have to notice that they are not allowed to insert inverse logic into the pins of a function block/an applied instruction to which operands are assigned. Graphical representation Example Example 1: The state of M0 is inverted, and the inversion result is sent to M1.
Likewise, the coil M1 will be driven if the normally-closed M0 is OFF. Example 2: The inverse logic inserted into the output node indicates that the result of the operation is inverted. The inversion result is sent to M3. 11-15