Features: 1.Working Principle: The converter can convert the TXD and RXD signals of the RS232 serial port into two wire balanced half duplex RS485 signals. 2.Simple Operation: no external power supply is required, you can directly steal power from pin 3 of the RS232 port, while requesting to send (RTS) on pin 7 and data terminal prepare (DTR) on pin 4 to supply auxiliary power to the converter. Resetup, hardware and installation are very simple to use. 3.Scope of Application: The converter of the bidirectional interface between RS232 and RS485 is used between the main control machines, and the main control machine and the microcontroller or peripherals form a point to point, point to multipoint remote multi machine communication net to achieve multi machine response communication. 4.Widely Used: widely used in industrial automation control system, one card, access control system, parking lot system, self service banking system, bus charging system, canteen sales system, company employee attendance management system, highway toll station system and so on. 5.ABS Material: Exquisite and compact, easy to operate and easy to carry. Made of high quality sturdy ABS material, wear resistant and durable. specification:Item Type: RS232 to RS485 Converter Material: ABS Serial Port The interface is compatible with EIA, TIA RS232C, RS485 standards Electrical interface: RS232C end DB9 female connector, RS485 end DBP pin connector, with terminal (three position connection) How it Works: Asynchronous Half Duplex Transmission Medium: Ordinary Wire, Twisted Pair or Shielded Wire Transmission Rate: 300 115200BPS Transmission Distance: Approx. 5meters (RS232 End) , Approx.1200meters (RS485 End) Communication Protocol: Transparent Signal: RS232: TXD, RXD, RTS, CTS, DTR, DSR, DCD, GND RS485: Date+, Date-, GND PackageList:1 x RS232 to RS485 Converter (Set of 2) 1 xChinese User Manual