Black Box Async RS232 to RS422/485 Interface Converter - DB9 to Terminal Block

Enables you to select RS-485 2-wire half-duplex or RS-485 4-wire full-duplex operation. Selectable RS-422 operation with transmit and receive always enabled. Automatic RS-485 driver control, so it works without any special programming for handshaking signals. Also enables transmitter from RS-232 TD signal and receiver when not transmitting. Built-in bridging switches for 2- or 4-wire operation with no external jumpers to set. Set operating mode with four switches. Converts using either port power or power from an external 120-VAC/12-VDC power supply (sold separately). No external power is required if two RS-232 output handshake lines are available.