Rarely a device may seize because of a power surge or a firmware issue that will cause a communication failure. After attempting to restart communications using the restart communications guide the device still will show a failed state. In this even you will need to manually reset this device.

First you will need to have access to the Win Sentinel Device Key. 

Locate the device in question, and unlock the device using the device key.

When you unlock the device you should be able to open the box which will display the intricate wiring and circuitry. We will not be moving and touching that stuff, so don't worry. 

On the board itself, we will be pushing and holding for 10 seconds a tiny reset button shown on the diagram below. 

DaVinci Keypad:

3200i Keypad:

After Resetting this device, you should restart communications on Win Sentinel Software Console

All Devices should register OK, If this still did not resolve the issue. Please open a support ticket and a trained technician will assist in resolving this issue.