MD2020 BCU

The Branch Control Module (BCU) is a crucial component designed to facilitate communication between the MD2020 Control Panel and addressable devices connected via the Branch communication line. Its primary function is to provide power to and manage communication with up to 180 addressable devices, ensuring seamless integration within a fire detection and alarm system. The BCU serves as an interface, enabling data exchange between the MD2020 Control Panel and the connected devices through the RS485 serial line.

Comprising essential elements such as a microprocessor, internal power supply circuit, RS485 interface, insulation surveillance circuit, and specific components for interfacing with the Branch, the BCU plays a central role in maintaining the integrity and functionality of the communication network. The microprocessor within the BCU manages communication protocols, stores system configurations, and assigns unique addresses to individual BCUs through DIP-switches on the front panel.

The BCU operates in different modes, functioning as either a Master or a Reserve. In the Master mode, it actively queries all elements on the Branch, including the corresponding BCU Reserve module connected to the end of the branch. This interrogation helps verify the integrity of the electrical connection. The cyclic exchange between Master and Reserve modes ensures continuous system functionality and serves as a mechanism for checking the operational status of the Reserve module.

In the event of a Branch interruption, both BCUs transition to Master mode, allowing each to control its respective section of the Branch. This redundancy ensures that the fire detection and alarm system continues to operate seamlessly, even in the face of potential disruptions.

The BCU is equipped with LED indicators on the front panel, providing visual feedback on various operational states, such as communication status, isolation integrity, microprocessor health, collisions, Branch interruptions, and the current Master/Reserve mode. The modular and user-friendly design of the BCU facilitates straightforward installation on a DIN rail using the TBUS Phoenix Contact™ connection system, allowing for hot-swappable insertion without interrupting power.