This IEC operator is used as a multiplexer.

‎OUT := MUX(K, IN0,...,INn)‎

Means: ‎OUT = IN_K‎

Permitted data type for ‎K‎: ‎BYTE‎, ‎WORD‎, ‎DWORD‎, ‎LWORD‎, ‎SINT‎, ‎USINT‎, ‎INT‎, ‎UINT‎, ‎DINT‎, ‎LINT‎, ‎ULINT‎, o‎UDINT‎.

‎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).

NOTICE

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

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