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• Semantic Error (SEM1030): Recursive dependency found in program organization unit '...'.

Semantic Error (SEM1030): Recursive dependency found in program organization unit '...'.

According to the IEC 61131 standard, recursive POU calls are not allowed.

In your project, two POUs are calling each other mutually. Such recursive dependency is not allowed as it may result in an unstable or unintended application behavior. The error message is reported once for each involved POU.

Note After deleting the mutual call in the code worksheets, also the relating FB instance declarations must be removed from the 'Variables' tables involved. The error remains as long as the instance declarations indicate a recursive use.

The error is also reported if a function block contains an instance variable of itself as the IEC 61131 standard prohibits that a POU calls itself.