ISPSoft User Manual 12.1.2 Calling a Function Block The important points about calling a function block on an instruction list are listed below. CAL, the function block instance and the left parenthesis must be in the same line while the other parts can be in different lines. The input/output pins of the function block and the corresponding operands must be put in parentheses. A pin and the corresponding operand form a group. The groups are separated by commas. The data types of the operands are specified in the function block definition.
The function block after CAL is a function block instance rather than a function block definition, that is, the symbol after CAL is a symbol whose data type is a function block. Please refer to chapter 7 for more information about function block definitions and function block instances. The assignment mark for an input pin is := , and the assignment mark for an output pin is => . The pins and the operands are arranged according to the definition of the function block. The arrangement can not be changed. The En pin and the Eno pin are excluded. The input pins are listed above all the output pins. A pin of the VAR_IN_OUT class is an input pin.
Please refer to the ladder diagram and the instruction list below for more information. The state of the En pin of the function block is not specified in the instruction CAL. When the instruction is be enabled. executed, the result of the logical operation before the instruction determines whether the function block will 12-4