how to distinguish between two zigbee wireless relays and 802.15.4 modems

I have two :
ZR220HP , zigbee wireless relay controllers
XBP24-AUI-EXT_ZIGMO , USB 802.15.4 Modem

They will be used to control a light. I am able to communicate with them using vb6. For example:

MSComm1.Output = Chr$(254)  'Turn Off Relay 1, RED OFF
MSComm1.Output = Chr$(0)

MSComm1.Output = Chr$(254)  'Turn On Relay 1, RED ON
MSComm1.Output = Chr$(1)

How can I distinguish between the two relays? Right now, one modem is controlling both relays.

In this case the radio is only acting as a wireless cable between the PC and the controller. How you control which relay is determined by the processor on the relay board and not the radio.