The MSR MAC-CPU-1 is the central processing unit and controller card designed for MSR-Electronic’s modular gas alarm systems, such as the PolyGard®2 series. As the core component of the system, this CPU card is responsible for processing signals from connected gas sensors, managing alarm thresholds, and activating relays for external warning devices or ventilation systems. It ensures reliable and continuous monitoring by overseeing all system functions, handling data logging, and facilitating communication between various system modules via its integrated RS-485 interface. The MAC-CPU-1 is essential for the configuration, operation, and overall performance of the gas detection and warning system.