ISA TR50.02, PART 9

INTRODUCTION

FIELD BUS PROCESS CONTROL USER LAYER TECHNICAL REPORT

The User Layer Technical Report is written as a functional design document for a hypothetical process control system. As such it is very complete in its description of data base structures and algorithmic implementation. The experience of the committee creating the User Layer was more easily focused on a document in this form. From the fixed structure and language in this Technical Report, the User Layer Standard could be formed by determining which parts of the "design" were the hard requirements and which reflected a model of an implementation. The completeness of the definition was also more easily tested using a model complete design, although the testing was primarily a "desk check".

The Technical Report can thus be considered to be a model of an implementation. That model is assumed to also form the base for the later effort of preparing a conformance test suite. Any implementation of a Field Bus device that responds to the conformance test in the same way as the model will be completely acceptable.