The ABB M2301 is a mini‑system controller and power supply module designed for ABB Welcome™ door entry and intercom systems. It serves as the central controller for small door‑communication systems, managing communication between outdoor stations, indoor stations, guard units, and other system components. In addition, it provides a BUS power supply to connected devices. The controller includes protection functions such as overheat, overcurrent, and lightning protection to guard against electrical stresses.