The H232B achieves the isolation of RS-232 TX, RX, GND 3wires signals. It is port-powered that no need external power supply. It’s also plus-and-play supported.
Standard DB9 male and female connector
Special port-powered technique, no need external power supply
TX,RX,GND 3wires signals isolation
Sheer transfers and baud rate auto-fitting, no need to change user’s protocol
15Kv static protecting and 600W/ms lightning protecting
Protecting the device from loop voltage, surge
RS-232 Isolator 
