Regarding configuration to be made for XBee communication

I recently bought two XBee series 2 modules one is with XB24 - Coordinator firmware and the other is with XB24-End node firmware. when i am trying to send data from co-ordinator to end node communication it is working properly. when i try to send data from end node to co-ordinator, I am facing issues data is not being sent. Is there any configuration changes to be made for getting this done?

Thanks in advance…

By default an End device sleeps, are you using CTS flow control to know when the module is awake and can receive data on the UART?

Thanks for your quick reply. I am trying to establish communication between XBee modules using Arduino. How can i know wether my End device is in Sleeping mode?. when i send data from co-ordinator module it is receving it. I am facing this issue only when i am trying to send data from end node to co-ordinator.

Try connecting and monitoring /CTS flow control the radio.

I am new to XBee. can you please provide procedure for monitoring CTS flow control? How can i set my end node to non sleep mode?

You set it as a Router instead of an End device. You see in the Zigbee world, end devices are intended to sleep. Where as Routers are always on parent devices that can also send and receive data via their UART as well.