The Omron CJ1W-SCU42 Programmable Logic Controller (PLC) Serial Communications Unit includes 4 serial ports compatible with RS-232C and RS-422A/485 interfaces. It supports host link, NT link, and serial gateway communication for Omron PLC networks. Manufactured by Omron, part of the Omron Programmable Logic Controller family, available under the Omron CJ1W Series.