PCT: Component-based Process Control Testbed

In the last years industrial control systems have increased their complexity, using a great variety of hardware and software elements of all kinds. In larger systems a big number of different protocols, communication networks and architectures can be found. System components are not centralized but distributed over the plant and they communicate with each other through several channels. Industrial control systems are usually organized in layers, and information used within/among them needs to be integrated. The general trend is to develop heterogeneous and distributed control systems, where system integration is a hard issue. CORBA is an open standard that provides a flexible middleware capable of integrating complex applications in heterogeneous environments, and could be a good choice when developing a control system. Nevertheless, CORBA has some limitations regarding to hard real-time applications, so it is only suitable for developing soft real-time systems. This paper describes the Process Control Testbed (PCT) of the IST Hard Real-time CORBA project (HRTC), which has been used to analyze and evaluate CORBA advantages and disadvantages in distributed real-time control systems development. The PCT system has been designed and implemented using CORBA and RTCORBA. A new version is being implemented using CCM Technology in the IST COMPARE project.