Cannot pass array of constant size to a function as a reference

2024-01-09T13:10:46.760000Z

It will be a reference, because it's a VAR_IN_OUT.

it's a little weird debugging the array online. It just shows as a POINTER TO INT, and you can't actually see the array from the function side. But you can still work with it as a normal array, not a pointer.

Cannot pass array of constant size to a function as a reference

2024-01-09T05:00:37.198000Z

okay but will this pass the array by copying it or it will be a reference to original array only.

Cannot pass array of constant size to a function as a reference

2024-01-08T14:32:22.323000Z

maybe this would be a better approach, then you don't have to pass the constant at all.

FUNCTION fun : INT
VAR_IN_OUT
    arr:        ARRAY[*] OF INT;
END_VAR
VAR
    lower:      DINT;
    upper:      DINT;
END_VAR

lower:= LOWER_BOUND(arr, 1);
upper:= UPPER_BOUND(arr, 1);

see here as well
https://help.codesys.com/api-content/2/codesys/3.5.13.0/en/_cds_vartypes_var_in_out/#constant-input-and-output-variable

Cannot pass array of constant size to a function as a reference

2024-01-08T05:13:45.020000Z

Could not find the solution to this issue but I have side stepped this by creating a global variable MAX_SIZE.

Cannot pass array of constant size to a function as a reference

2024-01-07T09:54:22.555000Z

I have a Array of constant size defined like this
`
Var Constant
MAX_SIZE :UINT := 10;
End_var

VAR
array : ARRAY[0..MAX_SIZE] OF INT;
END_VAR
`

Now I want to pass this array to a function by reference,

Function fun : INT
VAR IN_OUT CONSTANT
MAX_SIZE : UINT;
END_VAR
VAR_INPUT
array : REFERENCE TO ARRAY[0..MAX_SIZE] OF INT;
END_VAR

but when I run this it gives strange Errors

Error : Cannot Convert type 'ARRAY [0..MAX_SIZE] OF INT to type 'ARRAY[0..MAX_SIZE] OF INT

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