This IEC operator is used for calling function blocks.
In IL, CAL calls the instance of a function block.
CAL <function block> (<input variable1> := <value>, <input variableN> := <value>)
Example
Call of the Inst instance of a function block with assignment of the input variables Par1 and Par2 with 0 or TRUE.
CAL Inst(Par1 := 0, Par2 := TRUE);