Program Generators for Process Control Applications

Abstract

Programming of process control applications still represents a hard job. Reasons for this are mainly the following facts:•computer based process control systems contain mixed hardware as well as dedicated hardware,•man/machine as well as process/machine communication are decisive parts of the whole system, and•dedicated real-time operating systems or rather real-time executives are often necessary instead of general purpose real-time operating systems.Another crucial problem is the availability of the (very expensive) computer scientists during the maintenance phase who developed the application software. Therefore it is of interest to enable the end-user to “describe” as well as to maintain his application himself. Obviously an end-user must have at his disposal a great amount of detailed basic knowledge in the area of computer science.For many applications the only way out of this situation is the interactive use of program generators which produce object programs from fill -in-the-blanks type source “programs”. However, this method up to now is not widely known, although employed by numerous users. A reason for this is that basic concepts of fill -in-the-blanks type languages and program generators are only incompletely published. In most cases the language was developed starting with an analysis of the application and the design of a fill-in-the-blanks language. Afterwards the same or another team worked on its implementation. Very often the outcome of such projects - know-how, tools and modules -are ignored in daughter projects.The paper surveys the basic principles of program generators with respect to its usage for process control systems.