Operator: MUX

The IEC operator is used as a multiplexer.

OUT := MUX(K, IN0,...,INn)

That means: OUT = IN_K

Permitted data types for K: BYTE, WORD, DWORD, LWORD, SINT, USINT, INT, UINT, DINT, LINT, ULINT UDINT

IN0, …, INn and OUT: any identical data type

Make sure that variables of the identical type are used at all three positions, especially when using user-defined data types. The compiler checks for type identity and returns any compile errors. The assignment of function block instances to interface variables is specifically not supported.

MUX selects the K-th value from a set of values. The first value is K=0. If K is greater than the number of other inputs (n), then CODESYS passes on the last value (INn).

Important

For runtime optimization, CODESYS computes only the expression which precedes IN_K. However, in simulation mode, CODESYS computes all branches.

Example 127. Examples

Result in Var1: 30

Var1 := MUX(0,30,40,50,60,70,80);