V4002¶

Code: V4002
Message: Negative exponent in arithmetic operation

The program attempted to raise a value to a negative exponent using the EXPT function. IEC 61131-3 integer exponentiation does not support negative exponents.

Example¶

The following code will generate error V4002:

PROGRAM Main
VAR
    x : INT := 5;
    result : INT;
END_VAR
result := EXPT(x, -2);  (* Error: negative exponent *)
END_PROGRAM

The exponent -2 is negative, which is not supported for integer exponentiation.

To fix this error, ensure the exponent is non-negative:

Try it

Source

PROGRAM Main
VAR
    x : INT := 5;
    exp : INT := 2;
    result : INT;
END_VAR
IF exp >= 0 THEN
    result := EXPT(x, exp);
END_IF;
END_PROGRAM

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