That is dependent upon what protocol is being used in the TI chip and which XBee modules you have. If you are using the 802.15.4 version of the XBee modules and TI's code, it should be nothing more than setting the MM command on the XBee. If you are referring to a ZigBee stack on the TI chip. then you need to use the XBee ZB or SMT ZB modules for the XBee. You also then need to know if you are using the ZIgBee PRO stack, or 2006 stack. You will also need to know which profile you are using. If it is the Public profile for either the PRO or 2006 ZigBee standard, just set the ZS parameter.