In order to be a part of a ZigBee network, all nodes should have a common PAN ID, as well as 16-bit Operating PAN ID. The PAN ID is required to be manually provided to each ZigBee node, while Operational Pan ID is determined by the Coordinator node, and is then provided to all joining Routers and End Devices over-the-air.
If the Operational Pan ID of the Coordinator changes however but the PAN ID remains the same (due to firmware re-write or other reason), the Router and End Device nodes of the network will not be auto updated with the new Operational Pan ID. To prevent this situation, we recommend you implement one of the following solutions:
Solution 1 : Issue a Force Disassociation command.
You can issue AT command 'ATDA', which will force a Router/End Device to disconnect from the Coordinator immediately, then try to rejoin. By doing so, Router/End Device get the current Operational Pan ID on joining the Coordinator. Among the solutions listed, Routers will consume the least amount of time rejoining if done in this manner. Just don't forget to enable the Join parameter of you Coordinator (NJ=255) so the nodes can re-join!
Solution 2 : Enable Channel Verification
You can enable the Channel Verification parameter on Routers and End Devices, using AT command ATJV=1, followed by ATWR (or pressing the Apply button, if sending from a ConnectPort X gateway) to store the change. From then on, whenever the RESET button of a device is pressed or the Router/End Device powers up, it will verify the Coordinator is on its operating channel. If the Coordinator is no longer present, the device will leave its current network, then attempt to find a network to join (provided it finds a Coordinator with Joining enabled).
Solution 3 : Enable Network Watchdog
This seems to be the best solution of the three, as it requires zero user intervention. If Network Watchdog timeout is enabled using AT command 'ATNW', then the Routers/End Devices on the network will monitor communication with the Coordinator (or data collector), and will leave the network if communication with the Coordinator fails for a 3*NW period. The Network Watchdog timer is reset each time data is exchanged in either direction with the Coordinator (or if a Many-to-One Route broadcast is received.
Aug 23, 2017