8-Port RS-232/485 Serial Communications Interface
DNx-508-892
4-port, RS-232/422/485 serial communications board
DNx-SL-501
4-port, synchronous serial communications, HDLC, and SDLC protocol support
DNx-SL-504
4-port, RS-232/422/485 serial communications board
DNx-SL-501-804