[FUN] Selling the new Fieldbus Paradigm

[Stephen Mitschke]

Dear All,I'm curious how many have thought about this.Fieldbus is a technology that blurs the traditional "lines" that many of ushave between "systems" people and "instrument" people. In any organization,when one or the other of these groups is "sold" on using fieldbus, I'mguessing there's a high likelihood of resistance from the other. One or theother ends up traipsing on his/her counterparts' "turf".The net result is that progress is slow. (?)Seems like our suppliers have done little to address this . . . many remaindivided between people who sell systems and people who sell devices. Thepeople selling devices rarely talk to the customer's systems engineers, andthe systems guys rarely if ever talk to the customer's instrumentspecialists.It's different (maybe) with big projects, where it's more likely a singleindividual is making both the systems & devices decisions. And suppliers aremore likely to trot out a blended team of both systems and device people.I remember before DCS's became prevalent, the "craft lines" ( a term I hopeis familiar to those in non-union environments) didn't seem to be there. The"instrument engineer" did things like loop tuning, & he/she "configured" the"operator interface". But 25+ years of DCS have installed our currentgeneration of specialists, now each guarding their own turf.Anyhow, does it bother anyone else, the degree to which these "discipline"divisions (on both customer & supplier sides) might be hindering morewidespread or rapid adoption of fieldbus? Especially, when it comes toissues like "PID in field devices". Will we be waiting for a "generation" toturn over our ranks, before these "craft lines" become a non-issue?Is it a non-issue where you're at? Do suppliers see it as a non-issue?John RezabekBP

[Stephen Mitschke]

In my travels as fieldbus instructor, I have been to many a site where thedemarcation lines are concrete walls segregating these departments. I knowI'm generalizing when I say this but there are many instrumentationtechnologists that think the IT guys will never "get it" and the IT guyslove to baffle with BS using their favorite TLA (three letter acronym).Instrument Tech's feel that IT guys are better left to handle e-mail andplay with their "Nintendo Game Boy" while Information Tech's behave likethey're guarding the crown jewels when someone wants to check networksettings. John, I had this discussion at a facility two and a half years ago. (Andmany times since, for that matter) Once we opened up Pandora's box with bothparties in the same room, the best tack was to treat the problem as a thirdparty infringement... i.e. "Yeah, those vendors don't have both instrumentpeople and IT people on the same team... so we need to pull together to makesure we'll be ok." And so the rhetoric went. It was interesting how quicklythe walls came down when someone could facilitate the discussion betweenthese two parties. To this day the vendor still has isolation betweendivisions but the end-user is reportedly chugging along nicely. I'm noticing, though, that other vendors are still segregated as well. Allthe pressure that can be brought to bear against this would surely havefuture benefit, but the inertia that is inherent in some of these largervendor companies almost guarantees a "generation turnover". I recentlyvisited a particular vendor to learn that the integration of these twodepartments is genuinely complete. It's too bad that they aren't marketingvery strongly to promote such a boon.I think you have taken an appropriate approach... bring the issue to theforefront and have everyone become aware that it is a problem. This willfoster an element of business process re-engineering for the more alertorganizations. It may become the demise of the docile. If more of us draw attention to the need for harmonizing the two sectors,who knows, it may become the norm rather than the exception.Glad to have a forum to rant...Mike ClarkSouthern Alberta Institute of Technology

[Stephen Mitschke]

This is a serious issue that we are facing for some time as a manufacturer.With FF, the devices are powered with function blocks and becoming in factcontrollers, but still being field instruments. And when we have to talkabout a true distributed control system, you face problems where the systemguys are not interested in the devices, or they cannot select the devicessince it belongs to another department, and the intrumentation guys are notinterested on the control capability of the devices.As a manufacture, we had the same segregation on our sales force andtechnical people, where we have instrument sales people and system salespeople. We have spent a lot of time and effort to bring both concepts insidethe whole company without segregation, because when talking about a FFcontrol system, you have to talk about everything: Controllers,Workstations, devices and systems. And on the customer side, as pointed byMike, we have usually to put both parties together to evaluate the system,and sometimes, complete systems are misevaluated because each part (Systemand Devices) is evaluated separately.Best Regards, Claudio Fayad Smar

[Stephen Mitschke]

> I agree that too much division between instrument and control systems> people is harmful. For reasons that focus obsessively on human> limitations, some people have a hard time accepting that many individuals> can handle both at the same time. Of course, this anal reasoning has> everything to do with protecting turf. > > However, there are departments in companies where this form of segregation> is minimized, if not totally eliminated. These departments manage to do> more with less and hang on to their employees because you do not have team> polarization, where some can prance around like prima donnas and others> are told to be happy with the field work. Slowly but surely, companies> will come to realize the benefits of integration. This affects a lot more> than the future of fieldbus.> > Peter Mannistu> Staff Engineer - Controls (Syncrude Canada)

[Stephen Mitschke]

John Rezabek raises an excellent issue, not new but valid. I guess I am oneof those instrument people going back to pneumatic instruments andcontrollers. I gravitated to the computer camp after that, but I have neverleft my control engineering background behind. In the early meetings of SP50in 1986-1990 several of us felt that computer control and DCS was atemporary aberration until field instruments could get smarter. In theProcess Control Working Group of SP50, we always joked about the "microCray"that would be necessary to do full floating point feedback loop control infield instruments and especially in the control valve positioner. Fieldbuswas designed to handle the inter-instrument communications necessary toenable multilevel cascade control in field instruments -- just in case themicroCray ever became possible.Guess what? Embedded microprocessors running at low power with excellentperformance (microCray) are now available and have been designed intoFoundation Fieldbus instruments and control valve positioners. They cannotdo multilevel cascade control without Fieldbus. I guess we did it right, butonly because there were many talented control engineers laying thefoundation for Fieldbus.From the beginning, as soon as we started discussing control in fielddevices, the larger DCS companies began to sandbag the committee. Naturally,the DCS was their cash cow, and they did not want to see it subsumed bycontrol in the field instruments. It was only because of dedicated end usersfrom Exxon, Union Carbide, and Chevron, among others, that kept the effortfrom dying. Fieldbus was designed from the beginning to take over the lowestlevels of feedback loop control from the DCS so that all of thetime-critical control would be done in the instrumentation, not in somecomputer software.We focused on the advantages of Field Control as long ago as 1987 as wediscussed the PID function block location in the control valve positioner.We could see that having direct access to control valve stem position andbeing able to directly compensate for control valve friction was notpossible without local control. So far, this advantage has yet to berealized because of the gap between the control valve suppliers and theinstrument companies. It remains the primary source of benefit for Fieldbusinstruments -- vast improvements in control loop stability enabling tighterloop tuning and setpoint optimization. If you don't understand this, contactme.Dick Caro============================================Ri chard H. Caro, CEOCMC Associates