The communication of MCU and Xbee(2)


I have tried to send the command(+++) to the Xbee from my MCU successfully. I think the Xbee does reply the “OK” since it the yellow LED blinks.
There are 2 questions confuse me…

  1. I spent lot of time in going through the code and hardware. Because my MCU can not get any byte from the Xbee. Do I need to do any configuration of the Xbee? Should I use null-modem for this case?
    If I need to do some configurations, what should I do for Xbee sending data back to MCU?

  2. How can I intend to get the OK?
    I mean…Should I set my program to receive as “O”,“K”,"
    " or “O”,“K”,“\r” or “O”,“K”,“0xD”??

Many thanks for any reply