Issue
A MicroSmart controller is not communicating and the red watchdog timer (WDT) LED is on solid.
Environment
DMS
Cause
Possible hardware issue or power issue
Resolution
Things to try:
- Power cycle the controller
- Verify it has a good earth ground and 24 Vac
- Hardware clear the controller
- Replace the line driver and disconnect the communications trunk
- If it is a MSC-MPC, remove all modules. If the WDT LED begins flashing normally, re-connect the modules one at a time until the WDT LED goes solid
On-board hardware issue. Replace with another controller
