I have used rs-485 communications to communicate with point of sale terminals and access control terminal from PCs. Normally using an rs-485 card or an USB dongle.From the PC it appears as a virtual serial port, it depends on the driver that you have been provided.
Maybe with the idea i told u about still not sure, If i connected two PCs using MAX485 and tired to send from pc to the other i guess it should work, Just need to approve it before getting the converters.
I guess you would hook 2 chips up as specified in the datasheet and test bit error rates at various bit rates and lengths of twisted pair cable. RS-485 is specified up to 1200m of cable and data rates up to 10 Mb/s although not as the same time. You may also need to test over the temperature range specified in the datasheet. You might get by with using one computer with 2 ports in a loop configuration.
If you are using two USB to RS485 convertors, then you wouldn't need the MAX485 IC unless you wanted to add a third node such as an Arduino onto the bus, in which case you would attach the DI and RO pins to the Arduino's serial GPIO pins. You also need to connect the DE and RE enable pins to a GPIO port to be able to toggle the MAX485 driver between transmit and receive states.
Alternatively, you could use one USB to RS485 convertor connected to the PC and a MAX485 connected to an Arduino and send data from the SSCOM terminal application to the Arduino.
