sir...i am beginner in xbee..can u please tell me how to enable csma-ca algorithm in xbee

sir…i am beginner in xbee…can u please tell me how to enable csma-ca algorithm in xbee.
what are all the commands to enable the csma-ca protocol in a star topolopy

The CSMA function is enabled by default. You don’t need to do anything to enable it.

As for the Addressing, that depends on which XBee module you are using. In most of the Non Zigbee enabled products, it is as simple as setting the DL and DH of the transmitter side to the SL and SH of the receivers side. Then send your data just like you would a cable.

Thankyou very much sir,
I have 4 xbee s2c and I want to implent a star network in which 1 will be coordinator and other 3 will be routers connected with sensors like temperature, pir, gas along with arduino.
once coding has done using Arduinos all will start transmitting their respected values to coordinator. Now my question is that ‘is dat enough to code the Arduino in receiver side to receive all data as u said csma-ca is already enabled…?’
please help me in this issue.

sir, in my star network using 3 as routers and 1 as coordinator, whether all xbee I have to give same channel or different channel

In order to form a network, they must all have the same channel and PAN ID.