RS232 to RS485 converter :

                    RS-485 is a standard defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear. It helps in converting RS-485 communication to serial RS-232 communication, visa versa. This device can be easily connect to any microcontroller as well as PC. 

Specification & Features :

•     Compatibility: EIA/TIA RS232C standard and RS485 standard    
•     Interface RS232 side: DB9 female connector.    
•     Interface RS485 side: DB9 male connector with optional (included) terminal board.    
•     Transmission rate: 300 - 115200bps    
•     Transmission distance: RS485 max. 1200m, RS232 side max. 5m    
•     Working mode: asynchronous, half-duplex, differential transmission.    
•     Operating Voltage - 5volts DC