The 28A11A0 is an RS232 to RS485 / RS422 Converter with an RS232 DB9 Female Connector input and RS485/RS422 screw terminal output. It has a communication speed of upto 230Kbps and auto direction control for RS485-2W data transmission. The 28A11A0 has galvanic isolation of 1.5kV for RS232/RS485. This unit requires an external supply voltage of 9 to 26.4Vdc.