An ATS (Automatic Transfer Switch) controller is a device designed to monitor power sources and automatically switch between them to ensure a continuous power supply to critical loads. These controllers are commonly used in situations where a loss of power could have significant consequences, such as in hospitals, data centers, and industrial facilities.ATS controllers typically monitor two power sources:A primary source, which is usually the main utility grid power.A secondary or alternate source, which can be a backup generator, a second utility feed, or another reliable power source.