ZIGBEE PAIR MASTER 4DI 4DO COMMUNICATES ON ZIGBEE CUSTOM WIRELESS LINK 2.4GHZ UP TO 700M WIRELESS RANGE DIN RAIL MOUNT NEED ZT-2550 OR ZT-2570 TO CONNECT TO PC PAIR MASTER WITH ZT-2060 INPUTS ON 1 MODULE ARE LINKED TO OUTPUTS ON ANOTHER MODULE WITH NO PC INVOLVED