What is 485 bus?

The 485 bus is a type of communication bus used in digital communication systems. It is a standard-based bus designed to provide a simple, low-cost, and reliable interface between different devices. It is often used in industrial applications, such as process control systems, where multiple devices need to communicate with each other over a single cable.

The 485 bus is a half-duplex bus, which means that communication can occur in both directions over a single wire pair, but not at the same time. It uses differential signaling to provide robust and noise-resistant communication, which makes it suitable for use in harsh industrial environments.

The 485 bus is also known as RS-485, and it is a standard developed by the Electronic Industries Alliance (EIA) in the 1980s. It is widely adopted in the industrial automation and control systems industry, and it is used in a variety of applications, including building automation, HVAC systems, and manufacturing.