Lenze PLC Designer PLC Designer (R3-1) Uživatelský manuál stáhnout pdf (Strana 72)

L-force | PLC Designer

Concepts and Base Components

70 DMS 4.1 EN 03/2011 TD29 

Function call:

The call of a function in ST can appear as an operand in expressions.

In IL a function call only can be positioned within actions of a step or within a

transition.

Functions (in contrast to a program or function block) contain no internal state

information, that is, invocation of a function with the same arguments (input

parameters) always will yield the same values (output). For that reason functions may

not contain global variables and addresses.

Examples of function calls:

in IL:

in ST:

result := fct1(5, 3, 22);

in FBD:

Note: In contrast to »PLC Designer« V2.3 in function calls it is no longer possible to

mix explicit parameter assignment with implicit ones.

This allows to change the order of parameter input assignments.

Example:

fun(formal1 := actual1, actual2); // -> error message

fun(formal2 := actual2, formal1 := actual1); // same semantics as the following:

fun(formal1 := actual1, formal2 := actual2);

However you have to notice the different parameter assignment when using V2.3

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Lenze PLC Designer PLC Designer (R3-1) Uživatelský manuál Strana 72