Port Powered RS-232/422 Converter – DB9F & DB9F
These port-powered, two-channel converters change TD and RD RS-232 lines to balanced RS-422 signals extending communication distances up to 1.2 km (4000 ft). With port-powering, a power supply is not required. Power comes from the DTR and RTS RS-232 handshake control lines. At least one handshake line must be present, in either the positive or negative voltage state. This permits use in applications without worrying about software control of the handshake lines.