This is RS232 and RS485 two way converter, widely used in industrial automation environment: card read system, door surveillance system, parking lot system, ATM system, public transportation payment system, restaurant system, company attendance system, high way payment system, etc.
The convert will convert TXD and RXD signal of RS232 to two line balance semiduplex RS-485 singal. No need to connect power, power will be supplied from pin 3 of RS-232, and send request signal from pin 7 RTS, pin4 will prepare alternative power for converter, auto data flow is no need to reset, very easy setup.
Automatically detect the RS232 or RS485 and data way, so you can easily connect in either direction.
Compact size, long range transmission, high speed.
Compatible ETA/TIA RS-232C standard and RS-485 standard.
Interface: DB9 connect for RS232, and RS485, including one extra DB9 to screw terminal board.
Data speed 300~115-21BDS
Working mode: Asynchronous half-duplex
Transfer distance: 5 meters for RS-232 end, and 1200 meters for RS-485 end.
RS-232: TXD, RXD, RTS, CTS, DTR, DSR, DCD, GND
RS-485: Data+, Data-, GND
Convert signal from RS232 to RS485
On the end for RS485, you can connect up to 32 RS485 devices, need mach resistor 120ohm 1/4w to prevent interference.