I have the three XBee Series 2C modules configured as DigiMesh 2.4 TH. One is a coordinator, (Indirect Msg Coordinator , API Mode Without Escapes. The other 2 are Standard Routers and Transparent Mode. All have DH set to 0000 and DL set to FFFF. I'm using an Arduino type device to communicate with the coordinator over the rx/tx lines. I am able to get IO and A/D data from the routers using either IS, IR or IC Remote AT Command Requests . I have tried the same with the coordinator setting the IR and IC values with no luck using both AT Commands  and Remote AT Command Requests . The IS command works using the AT Command only. If I try to use the Remote AT Command, I get one correct response but no more after that. I have to power cycle the XBee to get it to work again.
My main question is can I use the coordinator in IC mode to send a response to the Arduino in response to an IO pin change or the IR mode to continuously send samples? So far I have written all my own code and have not tried any canned libraries.