as the radios can't pass the data
Wireless together with RS-422 is nonsense. RS-422 is based on current, which requires a pair of wires.
RS422 and it's half duplex brother (or sister) RS485 are based on differential voltage.
Officially, the RS-422 standard's title is Electrical Characteristics of Balanced Voltage Digital InterfaceCircuits, and is published by the ANSI Telecommunication Industry Association/Electronic IndustriesAssociation (TIA/EIA).