# comparison of costs of fieldbuses

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#### Stefan Staudt

In my opinion is it nearly impossible to compare different fieldbuses in general. I think it depends of the special purpose. Is there another opinion and does anyone knows a comparison of the costs of different fieldbuses?

Thanks,

Stefan

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#### Chris Duwe

Hi there,

thank you for the links which allow a quick access to information on the various fieldbus systems. However, there is no trace of comparison as it has been requested in this newsgroup. And it is still difficult to really compare the fieldbuses by price, performance and so on.

To my opinion it is essential for an end user, where one can obtain the products matching to the particular application and where one will get the
necessary support.

Of course it is important for a user to understand which field bus may have a special advantage in a particular application. Some examples:

Building up a plant is usually done with Profibus or DeviceNet. GM e.g. uses both.

But inside the product that is manufactured you find normally CAN if there is a fieldbus applied, or LIN for some low end car applications beside CAN. This inlcudes many PLC controlled applications.

Embedded applications usually include CAN, examples: cars (I count these applications as embedded), ships, air planes, medical equipment, printing machinery.
All major medical equipment manufacturers use CAN inside their products,
All car manufacturers use (or start using) CAN inside their cars.
In both cases 'ALL' includes Europe, Asia and North America

But on the other hand, there are a lot of applications running, which use a mixture of various fieldbuses for some reason. I am especially aware of this since my company supplies gateways, e.g. Profibus to DeviceNet,
Profibus to CAN, DeviceNet to CAN.

Special applications use other fieldbuses such as hart, fieldbus foundation etc. Interbus and bitbus e.g. are outdated fieldbuses that are
hardly used for new applications.

Since it is so difficult to generate comparable cost and performance surveys it is the best to contact the belonging user groups and ask for
examples of applications similar to the own application. Again, the surveys that I am aware of have never been neutral or objective, it was always very important, how (who) this survey has been paid for.

Best regards,

Chris Duwe
esd electronics

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#### Rob Hulsebos Philips CFT

>the various fieldbus systems. However, there is no trace of comparison as
>it has been requested in this newsgroup. And it is still difficult to
>really compare the fieldbuses by price, performance and so on.

I think the information you want to have doesn't exist, because there is no "the price" of a
fieldbus. What exists is: the price of the implementation of a fieldbus.

Suppose I buy a controllerboard for a protocol X at a vendor Y for $500 and a controllerboard for the same protocol X at another vendor Z for$1500.
What is now 'the price' of a fieldbus X?

(I once encountered this situation where X=a well-known German Protocol and Z a well-known very large German PLC supplier. Of course I bought Y
and got better customer-support as well).

Same holds for savings; the cost per I/O module, meter wire, manhour etc. is not the same in every company.

Performance is a different story. Perhaps you can elaborate a little bit on the application you are building and its characteristics? The readers of this list may then give insight based upon their experience with a particular system.

Greetings,
Ron Hulsebos