Wasn’t fieldbus communication expected to replace supposedly obsolete solutions? Do away with remote I/O systems? And get rid of conventional 4–20mA technology?
At least that’s what fieldbus evangelists have been telling us would happen. So farit has not. And it won’tnot any time soon anyway. In many casesthere is unfortunately still no simple answer to the question what bus is best for a given application.
Howeverthat is not to say the fieldbus concept as such is a passing fad. All three technologies coexistand all will continue to thrive. Thusfor end usersthere are good reasons to make a decision either wayand even better reasons to go for mixed implementations. After allconnecting a multitude of very basic digital signals in one of the more classic ways is not just a technologically sound choicebut likely the more economic one as well. Then againfor complex measuring transducerspositioners etcyou will want a fieldbus set-up nonetheless. So the best your manufacturer can do is integrate all available technologies into a comfortable solution that ensures maximum customer benefit – a field station serving all the best of the busload in a single unit.
R STAHL Schaltgeräte GmbH is based in WaldenburgGermany. www.stahl.de"