B+B SmartWorx RS-232 to RS-485 Converter - 1 x 25-pin DB-25 RS-232 Serial Female - 1 x 25-pin DB-25 RS-485 Serial Male

The RS-232 to RS-485 Converter converts unbalanced, full-duplex RS-232 signals to balanced full-duplex (4-wire), or half-duplex (2-wire) RS-485 signals. RS-485 is an enhanced version of the RS-422 balanced line standard.

The RS-232 port has a female DB25S type of connector with pins 2 (TD input) and 3(RD output) supported. Protective Ground (pin 1) and Signal Ground (pin 7) are also passed through. Pins 4(RTS) and 5(CTS) are tied together. Also pins 6(DSR), 8(CD), and 20(DTR) are tied together, but not passed through the converter. The RS-485 port has a male DB25P type of connector with the Send Data outputs on pins 2 and 14, and Receive Data inputs on pins 3 and 16 or 5 and 17.