"The keynote address noted how everything around us is benefiting greatly from a transformation from analog to digital such as television, telephony, and music. The latest developments in fieldbus deliver on the promise of digital networking. Fieldbus since years ago reduces wiring and the number of I/O cards. Now, with fieldbus power integrated into the interface card, the marshalling panel can also be eliminated, further reducing system footprint. It is well known that fieldbus takes the place of 4-20 mA, but fieldbus also takes the place of on/off signals. For instance, fieldbus on/off valves eliminate three wires per valve, provide feedback, and diagnostics. Similarly, for electric actuators / motor operated valves (MOV) more than a dozen wires per valve can be eliminated. In a fieldbus design an on/off valve can easily be changed to a control valve or MOV without redesigning wiring, barriers, or I/O cards because they have one and the same electrical connection. All the signals are marshaled from software, known as virtual marshalling or soft-wiring, which gives great flexibility to accommodate changes late in projects.
Multi-input temperature transmitters take the place of eight single input transmitters and associated wiring, ideal for temperature profiling applications on reactors. FOUNDATION fieldbus is taking the place of proprietary protocols for networked MOVs. Similarly, a fieldbus-based tank gauging system uses only a single pair of wires to connect all sensors on the tank and is intrinsically safe. This reduces wiring and eliminates need for flameproof installation methods. Diagnostics for all sensors is provided. A field mounted gas chromatograph eliminates the need for analyzer shelter and long sampling lines, instead using fieldbus as an "electronic sampling line". Gas chromatographs and other analyzers can be digitally integrated with the rest of the system.
The main part of the seminar gave an update on the project benefits of fieldbus at the various stages of a project including FEED, detail design, and installation & commissioning in view of the many enhancements to the fieldbus technology and fieldbus products and systems over the past several years. The second part covered life-cycle operational excellence and maintenance benefits.
Seminar in Perth
An end-user presentation was given by Ambrose Hargan of CSBP, who has reaped the real benefits of fieldbus for several years and has already deployed three systems. As an early adopter of FOUNDATION fieldbus, they found that the technology has matured and their experience grown. Using fieldbus and its associated tools and practices is now much easier. Recommendations included training on fieldbus and working with contractors experienced in fieldbus.
Closing remarks Many large projects in Australia are currently implementing FOUNDATION Fieldbus, particularly in the area of LNG. A key take away from the seminars was that a little fieldbus training goes a long way to ensure a successful project, and to fully exploit the potential of closed loop digital control and intelligent device management. The future is digital, don't build your plant on old technology. "