Understanding the RS-422 Interface

RS-422 Interface

RS422 interface RS422 interface. This interface is similar to RS485 interface.

The RS-422 interface is designed for multi-drop configurations, supporting up to 10 devices simultaneously.

It operates in balanced differential mode. It supports data rates ranging from 100 kbps to approximately 10 Mbps. The figure (not provided, but imagine one here) depicts a typical RS-422 pin configuration for a 9-pin connector.

RS422 Technical Specifications

The following table outlines the technical specifications of the RS422 interface:

SpecificationsRS422
Mode of operationDifferential
Number of drivers/receivers on one line1 driver, 10 receivers
Maximum cable length4000 feet
Maximum data rate10 Mbps
Maximum driver output voltage-0.25V to +6V
Maximum driver current in high impedance state (power off)+/-100 µA
Receiver input voltage range-10V to +10V
Receiver input sensitivity+/-200mV
Driver load impedance100 Ohms
Receiver Input Resistance4K min.