RS485 interface

Practically all of today's computer systems are equipped with an RS232 interface. That trusty and widely known serial interface enables a full-duplex link to be set up between two devices. Unfortunately, the applications of the RS232 interface remain limited to just that function. Sy contrast, the RS485 standard creates many more, and more advanced, possibilities. This article describes the operation of the RS485 bus, and how existing MCS51 microcontroller cards can be upgraded for small networking applications.