RS485 (terminal block) to RS232 (db9 female) converter
The 485SD9TB is a port-powered two-channel RS-232 to RS-485 converter. It converts the TD and RD RS-232 lines to balanced half-duplex RS-485 signals. The unit is powered from the RS-232 data and handshake lines whether the lines are high or low. An external power supply can be connected to two terminals on the RS-485 connector if no handshake lines are available. The 485SD9TB has a DB-9 female connector on the RS-232 side and a terminal block connector on the RS-485 side.
Brand name(s) : B&B Electronics

Not backwards compatible with RS422 (4 wire).
For an RS422 / 485 compatible converter (with DIP switch) see 4WSD9TB

Also known as "485", "RS485", & "RS-485"
For a compatible "low capacitance" cable , see 9842

Manufacturer datasheet - 485SD9TB (Adobe Reader required to read datasheet)