17 - What happens to data base configuration in a Fieldbus system?

Fieldbus is using the concept of a completely distributed database. Device and control loop information is encapsulated in the field device itself, ranges, tuning, wetted materials data etc. Any MMI that desires to display that information may access it. This way there are no duplicate inconsistent databases. In DCS synchronisation between the console and device database was not guaranteed.

There was always a risk that the device was calibrated for one flow range, but the console for another giving a wrong indication. In Fieldbus only one database exists, in the field device, and the MMI gets it scaling data from there. A hand-held configuration device accesses the same device data as the operator console.