# Xbee Series 2 Problems **URL:** \ **Category:** XBee - Zigbee\ **Created:** [November 25, 2008, 10:45am UTC](https://forums.digi.com/t/xbee-series-2-problems/2217 "2008-11-25T10:45:53Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Saxy](https://avatars.discourse-cdn.com/v4/letter/s/dfb087/32.png) [@Saxy](https://forums.digi.com/u/Saxy)\ **Post date:** [November 25, 2008, 10:45am UTC](https://forums.digi.com/t/xbee-series-2-problems/2217/1 "2008-11-25T10:45:53Z")
Hi to everybody, I’m a student of Electronics Engineering and I’m making my thesis about wireless communications improvement, using the zigbee technology. I’ve tried to learn the xbee specs by myself but I’m facing some problems I can’t solve, so I hope you can help me. I need to make my coordinator communicate with several xbee routers, by assembling modbus packets. At now I’m using the X-Ctu software (last release) and different xbee modules as routers (first and second series). My main problem is how to set the channel of communcation. The most routers were already installed here so I needed not to change their configuration. My coordinator has a Znet Coord AT (series 2 pro) firmware (last version), and its channel is not settable from the modem configuration. The existing routers channel is 10, while the coord one is 14 at now, and so it is not able to discover them. If I set the JV (channel verification) the coordinator can discover that router, but I can’t change all the existing routers configuration. (What’s the DD, Device Type Identifier, function? is it important that all the devices has the same identifier?) By the way I noticed that I can’t successfully assemble modbus commands if the channel is not matched (the router doesn’t send the answer and the command has no effect). Please tell me how can I change the Coordinator channel or how can I make it match with the routers one and what have I do to succesfully assemble my modbus commands, it’s really important!!! Thanks to everyone, Andrew ---
**Author:** ![Saxy](https://avatars.discourse-cdn.com/v4/letter/s/dfb087/32.png) [@Saxy](https://forums.digi.com/u/Saxy)\ **Post date:** [November 27, 2008, 9:43am UTC](https://forums.digi.com/t/xbee-series-2-problems/2217/2 "2008-11-27T09:43:06Z")
No one can help me??? ---
**Author:** ![fordcf2000](https://avatars.discourse-cdn.com/v4/letter/f/82dd89/32.png) [@fordcf2000](https://forums.digi.com/u/fordcf2000)\ **Post date:** [November 27, 2008, 3:57pm UTC](https://forums.digi.com/t/xbee-series-2-problems/2217/3 "2008-11-27T15:57:47Z")
To change the channel, change the scan channels “SC” option. The parameter is set as Hex but the channel is is determined bitwise. Example: To determine what channel you need you must look in the manual. To set the coordinator to channel 10 change the “SC” parameter to 20. If you look in the manual it says that it says that bit 5 is channel 10. Thus 0x20 = 100000. ---
**Author:** ![Saxy](https://avatars.discourse-cdn.com/v4/letter/s/dfb087/32.png) [@Saxy](https://forums.digi.com/u/Saxy)\ **Post date:** [November 27, 2008, 11:30pm UTC](https://forums.digi.com/t/xbee-series-2-problems/2217/4 "2008-11-27T23:30:44Z")
which manual are you refering to? the Xctu one or the xbee one? Thanks for your reply though! ---
**Author:** ![fordcf2000](https://avatars.discourse-cdn.com/v4/letter/f/82dd89/32.png) [@fordcf2000](https://forums.digi.com/u/fordcf2000)\ **Post date:** [November 27, 2008, 11:35pm UTC](https://forums.digi.com/t/xbee-series-2-problems/2217/5 "2008-11-27T23:35:29Z")
Look in the Xbee manual in the AT Command Reference table for the SC parameter. The manual tells you which bit corrensponds to which channel.