Applicable Systems
DVP
AH500
AS300
C2000
MS300
Symptoms
The watchdog timer has timed out. The PLC stopped executing the program to prevent uncontrolled operation.
Possible Causes
- Program scan time exceeds the watchdog timeout setting
- Infinite loop or very long subroutine blocking the scan cycle
Troubleshooting Steps
- Step 1: Check the scan time in the programming software
Scan time exceeds the watchdog limit - Step 2: Optimize the program to reduce scan time or increase watchdog setting
Scan time is within watchdog limit
How to Reset
To reset: Fix the scan time issue or adjust the watchdog timer, then restart the PLC.
Source: Delta DVP PLC Programming Manual, Delta Electronics
Category: PLC & VFD