Spatio-temporal constraints in fieldbus: Requirements and current solutions

Fieldbus are used to interconnect devices at the process level. At this level, temporal and spatial consistencies are of prime importance. The communication must provide ways to comply with these requirements.

In this paper, we explain the consistency requirements and show how they are supported in existing fieldbus proposals. This study shows that only FIP takes them into account, although partially, while the other proposals leave it to the application. Finally, we show how these requirements may be satisfied in a simple and efficient manner with minor modification and appropriate use of the FIP mechanisms.