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Semantic Error (SEM1276): Reading values of generic formal parameters is not allowed.

In an assignment statement in ST, the value of a single generic FB formal parameter is to be written to a variable. Read access to generic formal parameters (ANY* data types) is not allowed this way.

Error example

Although the variable a is of the data type INT, and the input BUF_INT of the BUF_TO_BYTE function block is of ANY_INT, the following read access is invalid.

a := BUF_TO_BYTE1.BUF_CNT;

Remedy

Double-clicking the error message opens the code and marks the incorrect code position. Delete the assignment of the generic FB formal parameter to the variable.