16 - Will Fieldbus replace DCS as we know it?
Yes. Some companies have a vested interest in saying that it wont, but with Fieldbus there is no need for analog and digital input cards (since communication is already digital) and there is no need for any controller "CPU" cards (since control is done in the field devices), nor is a "data high way" required to link the system together. All that will remain is the operator console. Ask yourself, is that a DCS as we know it?
The first DCS systems emerged more than twenty years ago. Though a major improvement at the time, this technology of yesteryear has many deficiencies. Fieldbus, jointly developed by Smar and many DCS manufacturers with combined expertise, has overcome these problems.
Established DCS manufacturers now offering their own PC based control software, or buying out PC software companies must be seen as the final nail in the coffin for DCS.
Many control software packages for PC today have all the bells and whistles of a DCS and are available for secure and stable operating systems. These are most likely to serve as operator consoles to make complete Fieldbus systems.
Lets look at what would happen if a shortsighted customer decided to go for the legacy DCS architecture of the 1970s, and then upgrade to Fieldbus a few years later. He would most likely have to replace the entire transmitter for all measurements (the Smar LD301 is one of few transmitters that surely can be upgraded to Fieldbus), wiring would have to be redone, power supplies, safety barriers and any interfaces would have to be replaced, input, output, CPU cards and "data-highway" (main and redundant) thrown away, and termination added - all that remains is the operator console. Upgradability to Fieldbus is an important consideration when choosing a control system.