RS485 is serial communication protocol which uses differential signals to transmit binary data.
It uses positive and negative 5V to create differential voltage.
RS485 is widely used as the communication in older EAC systems. It is a typeof serial communication that runs on differential balanced line over twistedpairs.
The data communication speed varies by the distance it travels.
Thedata speed can speed up to 35 Mbit/s (within 10 meters) or up to 100 kbit/s(1200 meters).
RS-485 is used as the physical layer underlying many standard and proprietary automation protocols used to implement industrial control systems, including the most common versions of Modbus and Profibus.
Newest Ultrasonic Level Sensor with RS485.
Advantages of RS485:
1.Communication is faster. Short response time between reader and software when less than 32 readers or controllers on the same data line.
2.The signal level interface is low.
3.Data transmission speed is maximum.
4.Support long cables up to 1200 meters but speed of communication drops from 35Mbit/s to 100kbit/s.
5.Good noise immunity.
6.Due to the balanced transmission line, it supports multiple slaves and a single master.
7. Reliable communication method if no 3rd party system sharing the data line.