Unknown Bytes in between two frames in XBee-Xbee link in API to API mode

HI,

My goal is to achieve the UART communication between XBee and Microcontreoller by sending data with another Xbee via XC-TU. I have configured both the modules in API firmware in Xbee Series 2.

I can sense the data in the microcontroller, if Xbee is in API Co-ordinator mode, which is connected to microcontroller. Second Xbee Router is in AT mode which is used to transmit data to Co-ordinator. Though, there are some unknown 16 bytes received in the starting of the reception and also in between two frames. I do not understand what it means?

When I change Router into API mode, I am able to access I/O on co-ordinator. But, microntroller connected to co-ordinator does not respond on the UART.

If anyone have a solution, please help me out.

Thanks

Vijay.

Vijay, what are the frames you are seeing?