P4097¶

Code: P4097
Message: Subscripted variable is not an array

This error occurs when a subscript list (x[1]) is written on a variable that is not an array. Only an array has elements for a subscript to select. The variables this rejects include:

an elementary value, such as a DINT, a WORD or a BOOL
a STRING or a WSTRING
a structure or a function block instance, and a field of one when the field is not itself an array
an element of an array that is not itself an array, such as values[1][2] on a one-dimensional values
a reference to something that is not an array, with or without ^

A subscript of a reference to an array selects an element of the array it refers to, so p[1] on a REF_TO ARRAY[1..3] OF DINT is accepted.

Example¶

The following code will generate error P4097 twice:

Try it

Source

TYPE
  Reading : STRUCT
    level : DINT;
  END_STRUCT;
END_TYPE

PROGRAM main
  VAR
    count : DINT;
    sensor : Reading;
  END_VAR
  count[1] := 5;             (* Error: count is a DINT *)
  count := sensor.level[1];  (* Error: the field level is a DINT *)
END_PROGRAM

count and the field level each hold one value, so there is no element for a subscript to select.

To fix this error, declare the variable or the field as an array, or remove the subscript:

Try it

Source

TYPE
  Reading : STRUCT
    level : ARRAY[1..4] OF DINT;
  END_STRUCT;
END_TYPE

PROGRAM main
  VAR
    counts : ARRAY[1..4] OF DINT;
    sensor : Reading;
  END_VAR
  counts[1] := 5;
  counts[2] := sensor.level[1];
END_PROGRAM

P4097¶

Example¶

See Also¶