Summary 
  In order to communicate between various standard series ports of computers, external equipments, or intelligent instruments, we must covert these signals first. This converter is compatible with RS-232C and RS-485 standard. It is able to covert RS-232 signal to RS-485 balanced differential signal and extend the communication distance to 1.2km. It is passive and doesnt require external power. It uses a particular pump to gain  power from RS-232 sognals (RTS, DTR, TXD) without initializing the RS-232 series interface.

FEATUREs
1.Compatibility: EIA/TIA RS232C standard and RS485 standard
2.Interface RS232 side: DB9 female connector.
3.Interface RS485 side: DB9 male connector with optional (included) terminal board.
4.Transmission rate: 300 - 115200bps
5.Transmission distance: RS485 max. 1200m, RS232 side max. 5m
6.Working mode: asynchronous, half-duplex, differential transmission.
7.Working environment: 0 ~ 70°C, relative humidity 5% - 95%
8.Mechanical dimensions: 95mm x 33mm x 17mm