Hi List:

I am working in the conceptual engineering of an expansion project. At this stage we are interested to evaluate fiedbuses instead of using of 4-20 mA wiring.
I would like to know what is the experience in full integration of fieldbus technology including instrumentation, drives, relays, electric scada, PLC´s, DCS, etc.
Also which technology is more used: Foundation Fieldbus, Profibus, Lon Bus, etc.

With thanks,
H. Vega

 

While it does not have as much support as some of the other fieldbus standards, I love MACRO - a fiber optic based fieldbus which is used mainly for motion control - over 1 Mb bandwidth. Delta Tau ( http:\\www.deltatau.com ) makes most of the products for it, and Lutze makes a really nice I/O subsystem that resides on it, and MTS- Performance Controls has a great amp solution that resides directly on the MACRO ring - saves wiring costs and complexity big time. Fiber is of course noise free, and update times are sufficient to allow direct PWM control of the
drives acros the fiber. We are running machines of up to 8 axes plus all associated I/O across it, and latency across the ring is for most practical purposes nonexistent. See http:\\www.macro.org for more info.

Davis Gentry
Controls Project Engineer
Carpenter Company

 

Herman
As a starting point for the use of field buses, I would like to recommend that you carefully consider the features required by your process. An
example is, what happens to the process if the communications link is broken? In some cases, such as machine control you may find it preferable to shut down the entire plant, however if you have a large plant involving separate processes it may be preferable for the link to be self healing or the portions of the plant to continue operating without the communication
link tying them together. Also in larger plants a combination of communication link may be a positive solution. Included in this pre analysis you will also need to consider what the devices do if they loose communications. Let's say we have an I/O block mounted remotely communicating back over some for of field bus, do we want
it to fail with all I/O high, or all I/O low or just to remember last state and keep every thing constant.
These are just a couple of point I found helpful when considering the use of different field bus technologies, there are many other points worthy of careful consideration before a decision is made.
Regards
Phill O'Meley
[email protected]

 

Hi there,

I personally wouldn't rely much on vendor's figures how many of fieldbus projects they sold.
Number of projects that have been started up successfully is the key figure -- but it is not available from any vendor.

Select fieldbus that supported by majority of vendors, that is suitable by application and, of course, cost effective.

I would select Foundation Fieldbus (FF) for analog control (www.fieldbus.org), and AS-i (www.as-interface.com) for discrete on/off control. The only DCS that fully supports FF at controller level (not PCMCIA card in PC) today is Fisher-Rosemount's DeltaV (www.easydeltav.com). FF has been successfully tested at many sites around the world. We have implemented three projects with FF in our country with DeltaV
without any hassle.

DeltaV will support AS-I and Profibus interfaces at controller level within few months.

Best regards
Andrei Murashko, [email protected]
FR Russia

 

At 17:11 02.02.00 -0400, Vega M. Hernan M. wrote:
>
> I am working in the conceptual engineering of an expansion project.
>At this stage we are interested to evaluate fiedbuses instead of using of 4-20 mA wiring.
>

For the first steps it could be interesting for you to visit the 'Fieldbus Portal' at http://www.steinhoff.de/fb_comp.htm , it's an
overview. The links to the homepages of all listed fieldbuses are included.

> I would like to know what is the experience in full integration of
>fieldbus technology including instrumentation, drives, relays, electric
>scada, PLC's, DCS, etc.

Fieldbus based solutions are running very successfully in the field since more than 10 years ... IMHO Fieldbus technology is a very
mature technology.

> Also which technology is more used: Fundation Fieldbus, Profibus,
>Lon Bus, etc.

- FF is more used in the process industry
- PROFIBUS-DP is more used in the material flow, machine control and factory automation
- LON is more used in the building and vehicle automation

Best Regards

Armin Steinhoff

 

Good response, Armin. I would just like to add that it is now clear that one of the issues requiring forethought on the part of engineering
companies is SYSTEM STAGING. There was a post here or in the InTech list recently about staging and factory testing of systems. Also, I helped to publish an article that is in the InTech site (but no search engine in ISA site, so can't locate right now) about a system installed in Malaysia for a wastewater treatment plant.

Possibly, a set of standards for fieldbus factory staging guidelines is required for future reference. Meanwhile, I'll search out my notes
from a year ago and try to assemble a follow-up.

Matthew da Silva, Yamatake
http://www.ycv.com