What is the difference between a RS422 and a RS485 signal?

Issue

Transmitting device is RS485, receiving device is RS422 or vice versa.

Product Line

Pelco Cameras, Pelco Matrix, Pelco Transmission & Power

Environment

All transmitting and receiving devices.

Cause

Confusion on compatibility using these media types.

Resolution

RS-485 is very similar to RS-422. So much so that it often causes confusion. Both are multi-drop, and both can communicate via very long distances.

RS-485 can have multiple Transmitting Devices and multiple Receiving Devices on the same bus, RS-422 can have only one Transmitting Device and multiple Receiving Devices.

If a system is compatible with RS422 than most of the time it will work with RS485.