E0016: a call that does not fit what it calls

A function is called with its inputs either all by name or all in order (Ed.3 6.6.1.4); a function block is called through an instance, not by its type name; := passes an input or in-out, => takes an output; every name must be one of the callee’s parameters. Every in-out is given a variable (Ed.3 6.6.1.4 rule 2): at each call of a function, and in a resource’s connections for a program, which bind it to a global.

VAR t : TON; END_VAR
TON(IN := x, PT := T#1s);     (* E0016: call an instance: t(...) *)
t(IN := x, Q := y);           (* E0016: Q is an output: Q => y *)
PROGRAM p WITH fast : counter;  (* E0016: counter's VAR_IN_OUT n is not
                                   connected: counter(n := g) *)

A program’s connection names what Ed.3 6.8.2’s grammar lets it (Prog_Data_Source, Data_Sink, Global_Var_Access): an input a constant, an enumerated value, a global variable or one field of one, or an address; an output a global variable, one field of one, or an address. An array’s element, an expression or a field of a field is none of them:

PROGRAM p WITH fast : counter(
    n := g,                     (* fine *)
    step := gp.x,               (* fine: one field of a global *)
    limit := ga[2],             (* E0016: an element *)
    start := g + 1);            (* E0016: an expression *)