Compiler error C0222

Message: Outputs can't be of type 'REFERENCE TO'

Possible error cause: An attempt is made to define ‎REFERNCE TO‎ as an output parameter.

Error correction: Do not use ‎REFERENCE TO‎ as an output parameter.

Example of the error:

PROGRAM PLC_PRG 
VAR
	inst : FB;
END_VAR

FUNCTION_BLOCK FB
VAR_OUTPUT
	re : REFERENCE TO INT;
END_VAR

--> C0222: Outputs can't be of type 'REFERENCE TO'