This book in the field of distributed control system (DCS) and software architecture addresses key issues like hardware and software modularity and platform dependency. The hardware and software complexity in DCS increases with the number of devices and the types of communication standards and interfaces used. Hence, to minimize the complexity in the design of DCS, there is a need for modular hardware architecture. Similarly, to minimize software complexity, there is a need for modular software architecture. Also, there is a need to accommodate and integrate various types of hardware devices that can support different applications, as most DCS are platform-dependent and application-specific. Therefore, to resolve these issues, this book aims to explain different software architecture styles for distributed control systems. The specified architecture suggests modularity in the design to find similar attributes, reducing design time, cost, and risk of errors. To conclude, the Layered Software Architecture for HDCS is introduced and described in brief.