This paper describes the software architecture design of a real-time monitoring system. The system has different configurations to produce a set of medium to high-end monitoring systems. The system was designed to meet the product line quality objectives of configurability, extensibility, and portability within the constraints of an embedded real-time system. These objectives were achieved using global analysis and the principle of separation of concerns to organize the architecture into multiple views. The major design artifacts in each of the views were: (1) a publish-subscribe communication protocol among software entities that allowed requirements to be isolated to a component; (2) a layered design that provided encapsulation of common services; (3) and a task structure that facilitated flexible process allocation.