Compiler error C0140

Message: Reference assign is only allowed to variables of Reference type

Possible error cause: An attempt is made to assign a reference value to a variable not defined as a reference type.

Error correction: Define the variable as a reference type.

Example of the error:

PROGRAM PLC_PRG
VAR
	i : INT;
	I_r : INT;
END_VAR

I_r REF= i;

--> C0140: Reference assign is only allowed to variables of Reference type

Error correction:

Example:
I_r : REFERENCE TO INT;