X-CTU / Xbee: unable to communicate with modem

In X-CTU, when I push on “test/query” I get this error message half the time: "unable to communicate with modem
I am using Xbee S2
Thanks for your help.


Do you know if the XBee module is configured in AT mode or in API mode? Is it a router or an sleeping device?

If you don’t know how is it configured check the Enable API setting and configure the baud rate to 9600. Then follow these steps:

  1. The XBee module could be sleeping, press the Reset button of the XBee Interface Board device and try to establish communication again.
  2. Change the Baud setting with a different value (usually it should be 9600 or 115200) and retry the process repeating the previous step until you get a communication success message.
  3. Your XBee module could be configured in AT mode. Uncheck the Enable API setting and retry again repeating steps 1 and 2.

Hope that helps.


Error messages in XCTU are frequent when your baud rate and/or API setting don’t match the Xbee. As Diego says, you should try to match XCTU as closely to your XBee as possible.

So if you baud rate is 19200 with API, but XCTU is 9600 no-API, then yes XCTU will rarely fund the XBee. If you see errors only half the time, you are lucky.

Hello Diegoe, I had the same problem and I’ve just done what you said. I don’t have an Xbee adapter (I’m using an Xbee Serie 1 connected to an Arduino UNO) so I’ve checked the “Enable API” box and changed the baud rate to “115200” and the communication with the modem was OK. It shows the ID but not the firmware.

Now I went on Modem configuration tab and I click on “Read” but nothing happens, it failed to enter in command mode.

Thanks for helping…

Happy Saturday.