Stored-Program Controllers: Quick Diagnostics Avoids Expensive Down Times.

Despite continuously advancing automation, troubles and failures in operational processes cannot be fully excluded even today. As the economic efficiency of a system depends on its availability, down times must be avoided. Practical experience has shown that over 98% of all troubles occur at the interface of the electronic and mechanical systems and not in the control system itself. Due to the ever increasing capability of the stored program controllers (SPC), the requirement for a convenient and intelligent process monitoring system and for an automatic diagnosis is given increasing attention. Malfunctions must be detected, localized and displayed in a quick and safe way. A newly developed diagnostical subassembly for an existing process control system is described.