USB to EIA-232—Interact with SEL relays and other devices by connecting the USB Standard-A plug to a 9-pin male (SEL-C662) or female (SEL-C663) serial port.
Add Serial Ports to Personal Computers
Use serial data rates up to 115,200 bps. Many devices communicate with EIA-232 serial ports, but many new computers do not have sufficient built-in serial ports. Apply SEL adapter cables to use a USB port to communicate with serial devices.