Attention

IronPLC supports IEC 61131-3 Structured Text excluding I/O mapping.

V4003

Code

V4003

Message

Task exceeded its watchdog time limit

A task exceeded the configured watchdog time limit (max_scan_time). This typically indicates an infinite loop or unexpectedly long computation.

Example

The following code may generate error V4003:

PROGRAM Main
VAR
    i : INT := 0;
END_VAR
WHILE i < 10 DO
    (* Error: i is never incremented, loop never terminates *)
END_WHILE;
END_PROGRAM

The WHILE loop never terminates because i is never incremented, causing the task to exceed the watchdog time limit.

To fix this error, check loop termination conditions and ensure the loop variable is updated: