MMS implementation based on a real-time operating system kernel

MMS (Manufacturing Message Specification) is an international standard that concerns integration of shop-floor devices such as numerically controlled (NC) machine tools, robots, programmable logic controllers (PLCs), and control computer systems. MMS introduces the concept of a Virtual Manufacturing Device (VMD) providing a common view of all physical devices. Wide spread use of MMS in industrial plants depends heavily on real-time support. This paper presents an approach to the implementation of an MMS server for shop-floor devices that takes into account real-time requirements. Our MMS server has a dynamically reconfigurable software architecture of a Real-Time Control Operating System (RTCOS). It is based on Microware's OS-9 real-time multitasking operating system kernel. In our framework, multiple reconfigurable control sub-systems represent multiple Virtual Manufacturing Devices (VMD). The sub-systems can be developed independently of target driver devices. This paper focus on the software architecture of our Real-time Control Operating system MMS Server called RCOMS and discusses the advantages of our approach compared to other MMS implementations.