Copy from TI E2E Community.

question:

 My problem is that in the system we are building, there will be typically one coordinator, and one end device.

If multiple of these systems are deployed in the same area, and the end device is powered down and back up, it needs to remember which coordinator it was last connected to, and reconnect to that one. Its not possible to run it all under one coordinator, as the coordinators are not owned by the same user.

Currently, as far as I can tell, the PANID is ignored by the end device – it will connect to a coordinator that is configured to a different PAN id as itself.

The end device needs to get a list of coordinators available, and then select the appropriate one.

Also, the coordinator should ideally be able to check to see if the PANID it would use is in use, and pick a different one if it is.

answer:

If you have a device join a network and you would like that device to be able to sleep or be turned off, come back up and remain a member of the same network (not go through the discovery and joining process again) then you can use the NV_RESTORE feature which saves the state of the device to Non-Volatile memory and refreshes the status of the device on the network when it is powered back up.  Please check the developer's guide for more information on NV_RESTORE.