PurposeThis paper sets out to highlight the problem associated with the development of fieldbus diagnostics in a multi‐vendor environment and to propose a solution based on diagnostic function blocks (FB).Design/methodology/approachThe work focuses on the “master‐slave” communication model in a PROFIBUS fieldbus system, where three different vendor solutions are investigated.FindingsAlthough the fieldbus standards specify the type and format of the diagnostics data, the extent, location and sequence of diagnostics data within a controller are entirely vendor‐dependent. The outcome from this work defines a framework for representing the diagnostics data in the context of a special function block.Originality/valueThis research work defines a novel unified framework for representing the fieldbus diagnostics data using FB for multi‐vendor solutions in a PROFIBUS environment.

Increasingly fieldbuses are used in a variety of applications as the end users make large investments on fieldbus installations. Therefore the availability of these fieldbuses is of paramount importance in smooth plant operation. Although the fieldbus standards specify the type and format of the diagnostics data, the extent, location and sequence of diagnostics data within a controller is entirely vendor dependent. As the number of differing controller makes increase in an installation, so does the problem of accessing fieldbus diagnostics data.