That is correct. All you need to do is to set the DL and or DH to the address of the coordinator. However you are using an 802.15.4 product and not a ZigBee product. ZigBee is a higher level protocol that runs on top of the 802.15.4 PHY and MAC layers which allows for routing of data. The radios you are using only perform Peer to peer, point to point and point to multi-point networks. (See http://www.digi.com/support/kbase/kbaseresultdetl.jsp?id=2187)