SA0105: Multiple instance calls

Function	Determines and reports instances of function blocks that are called more than once. To ensure that an error message for a repeatedly called function block instance is generated, the attribute {attribute 'analysis:report-multiple-instance-call'} must be added in the declaration part of the function block.
Reason	Some function blocks are designed such that they can only be called once in a cycle. This test checks whether a call is made at several points.
Importance	Low
PLCopen rule	CP16/CP20

Sample:

In the following sample the Static Analysis will issue an error for fb2, since the instance is called more than once, and the function block is declared with the required attribute.

Function block FB_Test1 without attribute:

FUNCTION_BLOCK FB_Test1

Function block FB_Test2 with attribute:

{attribute 'analysis:report-multiple-instance-calls'}
FUNCTION_BLOCK FB_Test2

MAIN program:

PROGRAM MAIN 
VAR
    fb1  : FB_Test1;
    fb2  : FB_Test2; 
END_VAR

fb1();
fb1();
fb2();                           // => SA0105 
fb2();                           // => SA0105