First, use 

 D485C, D485A-based MCU with RS-232/RS-485/RS-422 converter for RS-232 to the microcontroller serial port (TTL level) into RS-485/422 level. D485A, D485C Serial port can be extended to 1200m or more communication distance (9600bps), the MCU can be used between the MCU and composition between the remote PC, multi-machine communications network. For the full-duplex half-duplex Universal D485C, D485A is half duplex. 

 Second, the hardware installation 

 D485A, D485C MCU RS-232/RS-485 converter with adapter box shape for the DB-9/DB-9 size, which DB-9 (socket) of a termination microcontroller serial port RS-232 (only to RXD, TXD, GND) and +5 V power supply. DB-9 pin holder to the converted RS-485 signals. D485A, D485C can RS-232/RS-485 SCM smart two-way conversion. All microcontroller connected to the converter common ground, requiring single chip ground interconnect between the voltage should be less than 1 volt. 

 Third, the software 

 The products do not need any initialization settings! Send and receive control signals without conversion! SCM is used only serial port RS-232 RXD (receive), TXD (fat), GND (ground) signal, with a unique zero-latency automatic send and receive internal conversion technology, to ensure that suitable for all software! Fourth, the performance that D485A, D485C MCU RS-232/RS-485 converter with an external 5V power supply, the highest rate of 115.2Kbps. External Power Requirements: Voltage 5V ± 0.5V, current> 10mA.