Passing I/O into a procedure

Hi, I want to be able to pass I/O into a procedure. The closest I have come is (see below) but “signaldi” is not a value. Is there a way to do this?

PROC ProcIO (signaldi blah1, signaldo blah2)
SetDO blah2,1;
WaitDI blah1, 1;
ENDPROC

Hello,

If I remember well you need to add VAR to your routine declaration:

PROC ProcIO (VAR signaldi blah1,VAR signaldo blah2)

BR

Peter