B&B 4WSD9R - serial adapter

The 4WSD9R Universal Converter is a port-powered or externally powered two-channel RS-232 to RS-422/RS-485 converter. It converts TD and RD RS-232 lines to balanced RS-422 or RS-485 signals. RS-485 is an enhanced version of the RS-422 standard, allowing multiple drivers and receivers on a two-wire system. The unit is powered from the RS- 232 data and handshake lines whether the lines are high or low. Or, if there is not enough power on the port, it can be powered by an external +12VDC 100mA supply. The 4WSD9R has DB-9 female connectors on both the RS-232 side and the RS-485 side. The RS-232 connector is configured as DCE (like a modem).