Xbee end device changes channel?


I am doing one project with Xbee modules, and I have been testing Xbee network for several months. Recently, I had one strange “bug”, and I can’t figure out what is the problem.
I have XbeePro series2 (XBP24-B) set as ZNET 2.5 Coordinator API, and three Xbee S2 (XB24-B) set as ZNET 2.5 END DEVICE/ROUTER API.
Each module is controlled by a PIC microcontroller. After powering up, PIC sends “JV=1” AT command (enabling Channel Verification) to end devices, so end device will join specific channel only if there is a coordinator on that channel.
Few times I noticed that after some time, coordinator didn’t communicate with end devices properly. After some searching what went wrong, I noticed that two end devices changed channel, from channel 12 to channel 17. I don’t know how is this possible… Microcontroller is sending some log messages, and one of these messages is end device’s current channel, so I noticed that sometimes end device leaves its current channel, and returns that operating channel is 0.
Could you tell me few reasons, when could end device/router leave it’s operating channel?
I read section about leaving a network in digi’s document no. 90000976_G, but I don’t use none of the mentioned AT commands ( ID, SC, ZS, NR0, NR1).

Also, how it is possible that end device joins channel 17 if coordinator is working on channel 12?

Thank you!


After changing the channel, if the end devices are not in the same PAN ID, then following might be the reasons

•The ID command changes such that the current 64-bit PAN ID is invalid.
•The SC command changes such that the current operating channel (CH) is not included in the channel
•The ZS or any of the security command values change.
•The NR0 command is issued to cause the end device to leave.
•The NR1 command is issued to send a broadcast transmission, causing all devices in the network to leave
and migrate to a different channel.
•The commissioning button is pressed 4 times or the CB command is issued with a parameter of 4.
•The end device’s parent is powered down or the end device is moved out of range of the parent such that
the end device fails to receive poll acknowledgment messages.


I am doing one project xbee pro based.In my project i used 4 xbee pro module.how i communicate the four module if i select one module coordinator other router means how i am config xctu. plz tell me u have any link