I want my PC (master) talks with my rabbit 3000 card (slave). I want to use RS485 and Modbus RTU (slave)in my application. I use Realterm ...

what can I do it? I configure real term ..but I see nothing...Someone use rabbit card before???

 

Hi there,

Well, the PC´s comport uses RS232 and thus you will need a converter RS232 to RS485. There are several manufactures that make RS232 to RS485 converters, use google to find one that will fit your needs. westermo are known for their quality..

//Patrick

 

Make sure you use a RS232/RS485 converter that automatically handles the RS485 KEY UP/DOWN. Otherwise you will need to send a sacrificial character at the end of every Host poll AFTER you detect Tx Empty etc etc....a royal pain.

 

The DGH DIN-191 RS232/RS485 serial converter will automatically control the RS485 driver keyup/keydown. It's +5V powered, DIN mount, 300-115.2K baud.

http://www.dghcorp.com/din/din190.htm