Difference Between RS485, RS422, RS423 and RS232


#1

Line Drivers and receivers are usually used when there is a data exchange between 2 or more devices in a network. What is the difference between each transmission protocols (RS485, RS422, RS423 and RS232) in data communication?

Below comparsion table between RS485, RS422, RS423 and RS232 can help.

Specification RS485 RS422 RS423 RS232
Line Configuration Differential Differential Single-ended Single-ended
Total number of Tx and Rx on one line 32Tx 32Rx 1Tx 10Rx 1Tx 10Rx 1Tx 1Rx
Maximum Cable Distance (at 1000kbps) ~4000 feet ~4000 feet ~4000 feet ~50 feet
Maximum Data Rate (for 50 feet) 10Mbps 10Mbps 100kbps 20kbps
Typical logic levels ±1.5V~±6V ±2V~±6V ±3.6V~±6V ±5V~±25V
Tx load impedance 54Ω 100Ω >=450Ω 3k - 7kΩ
Maximum Rx input resistance 12kΩ 4kΩ 4kΩ 3~7kΩ
Receiver input sensitivity ± 200mV ± 200mV ± 200mV ± 3V