3. Overall Architecture

A complex system like the GMT has many parts and behaviors that require control. The overall architecture of the GMT Software and Controls System (SWCS) has to capture many essential aspects of the observatory as a whole: from the system organization, physical and behavioral properties of the systems and subsystems, their control hierarchy, communication and interaction of the subcomponents under control, runtime operations, to how human operators would use the telescope. Together, they provide a coherent yet still schematic narrative of the overall system. They further filter down and are refined into technical and operational requirements that become the basis around which detailed designs of the control software may begin. The software architecture is a process that captures decisions to best meet the requirements at the system level, while optimizing over parameters to meet the General Principles and Guidelines, in particular, performance, reliability, maintainability, and cost. The discussion below gives a summary of the overall SWCS architecture from several different top-level perspectives, i.e. from the standpoint of the SWCS organization, the global SWCS domains, software development layers, software deployment layers, control hierarchy, system health and supervision, software frameworks, and the subsystem modules.

• 3.1. Organization
• 3.2. Domains of Control
• 3.3. Software Development
• 3.4. Software Deployment
• 3.5. Controls Hierarchy
• 3.6. Health and Supervision
• 3.7. Frameworks
• 3.8. Modules: Subsystem, Packages, Components
• 3.9. Instrument Software and Controls Integration