The industrial automation business is extremely fragmented, with very few products that literally sell in the millions. Silicon chips used in industrial controls typically cannot support volumes beyond a few hundreds of thousands, and hence silicon designed specifically for industrial products cannot achieve a pricing level that compares with consumer products.
Therefore, the best alternative for designers of industrial controls is to `piggyback’ on chips that are already used in high volume in other markets.
Echelon’s LONworks technology was initially a contender for low-level industrial networking, though it has made more headway in building-automation markets rather than industrial applications. The LON chip is manufactured by Toshiba and is available in high quantity at a price of about $5. Profibus chips are available primarily under license from Siemens, and similarly, ControlNet chips are available only from Rockwell (Allen-Bradley).
The CAN chip – Control Area Network – was developed originally by Bosch in Europe and is used extensively in the automobile business to eliminate wire-harnesses. CAN-chips are manufactured by Motorola, Intel, and several others, with volume already yielding cost at about $3 in reasonable quantities.
At the Fieldbus level, although silicon is available, the chip-prices and complexity of implementation are still indicative of early stages of development. Recognising that `higher-level’ Fieldbus is significantly more complex, with the added burden of the politics of committee-cooperation, it is unlikely that final silicon will be available at anywhere near the cost which justifies general application in `low level’ industrial networking.
This limitation also inhibits increase of volume. In any case, under the best of circumstances, total worldwide unit volume is unlikely to exceed a few million, which is a relatively small quantity in the silicon production environment. Also, the chip (at least initially) will be relatively large in size, which keeps the price relatively high (perhaps $25). For these reasons, Fieldbus is still relegated to amorphous `higher level’ applications, the realm of proprietary vendor/user partnerships rather than multi-vendor interoperability.