1. Select RS422 or RS485 Mode

The JP1 is used to select RS422 or RS485 for port 1 and the JP3 is used to select RS422 or RS485 for port 2. To short pin 1,2 means select RS422 mode, otherwise to short pin 2,3 means select RS485 mode. 

 2. Select Receive Mode

 The JP2 and JP4 are used to select receive mode. To short 1,2 means select receive always enable, and short 2,3 means select RTS to enable receive. The JP2 is used to select receive mode for port 1 and the JP4 is used to select receive mode for port 2. 

 3. Select High Speed or Normal Speed Mode

 The JP5 and JP6 are used to select high speed mode or normal speed mode; the clock is 7.3728MHZ for high-speed mode, and 1.8432MHZ for normal speed mode. For high-speed mode, the baud rate speed up to 460K. The JP5 is used to select speed for port 1 and the JP6 is used to select speed for port 2.