I am trying to communicate between two uBoards. I am using 2 RF Modules XBee S2 ZB, one set as a Coordinator AT(called #1) and the second as an end device AT (called #2). The two uBoards exchange data. Board A with module 1 will accept data from board B and module 2 but will not transmit data to B. If I swap modules Board A with #2 will send data to board B with #1 but B will not send to A. If I change firmware so #2 is now a coordinator AT and #1 is the end device AT. The board with the revised coordinator module will not transmit data. Any suggestion as to what I have worn in my settings?