Yes, you can use NP1L-RS1/RS4/RS5 for RS-422 devices. RS-485 is upper compatible with RS-422. There are two connection types for RS-422 devices: 2-wire connection and 4-wire connection. 1) When the other device uses 2-wire connection method, perform external wiring as described in '6-2-1 When RS-485 is used (2-wire)' in the user's manual FEH225. In addition, in the parameter setting (PARA array) of a communication FB (e.g. '_C_frp2'), select '1: 2-wire' for the parameter No.12 'RS-485 mode.' 2) When the other device uses 4-wire connection method, perform external wiring as described in '6-2-2 When RS-485 is used (4-wire)' in the user's manual FEH225. In addition, in the parameter setting (PARA array) of a communication FB (e.g. '_C_frp2'), select '0: 4-wire' for the parameter No.12 'RS-485 mode.'