What are the differences between RS-422 and RS-485?
Briefly, the main difference is that an RS-422 bus can have only one driver, but up to 10 receivers (denoted as multi-drop). An RS-485 bus is a true “multi-point” network in that there can be multiple drivers on the bus, and any combination of 32 drivers and receivers. Because multiple drivers can share a bus, RS-485 drivers must also be able to survive bus contention without sustaining damage. RS-485 is the more restrictive spec, so RS-485 devices are also RS-422 compliant.
