Use periodic sampling, set IR on the end devices to some non zero value and provide the destination address on the end nodes as SH and SL of the Coordinator(ConnectPort X4 gateway).
Only devices running API firmware can send IO data samples out their UART. Devices running AT firmware will discard received IO data samples. A sleeping end device will transmit periodic IO samples at the IR rate until the ST timer expires and the device can resume sleeping.
Progamming Option -
To receive the IO samples on the X4, You would bind on the socket ("", 0xe8, 0xc105, 0x92) to receive all incoming 'IS' responses and decode them per the XBee documentation. Latest Documents can be found in Digi website under Support http://www.digi.com/support/
Aug 08, 2017