By
Jim Montague, Executive Editor
IĀve been watching nature shows on TV since I was a little kid, starting with Mutual of OmahaĀs Wild Kingdom and Jacques Cousteau and right on through to the latest episode of Nature on PBS (pbs.org/wnet/nature). And, as those 40 years have gone by, IĀve started to ask if all of the tracking, studying, tagging and other research actually helps the animals and their environments?
Despite the obsessive studying, more species, wetlands, rainforests, coral reefs, migration routes and other irreplaceable resources keep dying and vanishing all the time. Perhaps we should just rope off a few sections of the planet, and leave the animals the hell alone. Less prodding. More preserving.
Why the tree hugging rant? Well, IĀve been covering industrial networks for about 10 years, and IĀve noticed a few similarities.
Hundreds of engineers, technical professionals, nonprofit trade organizations and suppliers have been earnestly developing, expanding and promoting ostensibly open standards for fieldbuses, Ethernet flavors and now wireless for many years. Most of these standards are based on formerly proprietary technologies that were donated by suppliers to these fieldbus organizations. Since then, these groups have helped draft standards, developed training and compliance testing methods and even sought greater cooperation and interoperability via more-inclusive standards.
But what good actually has been accomplished here? Certainly, many users are adopting fieldbuses and Ethernet successfully; twisted-pair networking finally is making substantial gains on traditional 4-20 mA hardwiring; and joint efforts on Electronic Device Description Language (EDDL), OPC-UA, Wireless HART, and related ISA-based standards promise easier networking in the future.
However, I seem to run across just as many end users experiencing crippling communication barriers and nonexistent interoperability. On the plant floor all the promises disappear, and theyĀre left with devices that are difficult to program, donĀt secure crucial data from I/O or field sensors, arenĀt protected from electrical noise, canĀt manage data scheduling conflicts and collisions or justĀ donĀt function well in their applications. They add that initial boasts of interoperability are too often just a Potemkin village that dissolves into subtle hints they really should standardize on one or a small group of technologies and replace prohibitively expensive sections of their existing networks. In addition, they say promoters who demonstrate interoperability with their own components at trade shows frequently canĀt work the same magic when asked to test their equipment on a plant floor running a half dozen different communication protocols.
Sure, these end users might be part of a bellyaching minority just looking for a way to justify not coming into the 21st Century and investing in networks that will do them the most good. However, my reporting usually turns up a representative cross-section of users, so I donĀt think all of them can be whining unjustifiably.
Similarly, while researching this issueĀs ĀCooperateĀ cover story, I found the usual helpful experts on interoperating within their own fieldbuses. Unfortunately, few have advice on how to network between these conceptual silos or specific examples of users successfully interoperating between DeviceNet, Profibus, Foundation fieldbus and other network protocols. For example, even mighty Ethernet is just a wiring specification that carries many languages, whichĀ still canĀt talk to each other without plenty of added programming and technical assistance.
Ironically, switches and gateways can provide bridges, but how truly open is your protocolĀs software if you still need a piece of hardware to translate for you? ItĀs lucky that hardware has no pride, or else the readout on the module the software was supposed to replace might read, ĀBite me.Ā In fact, some users tell me they now can put enough software-based intelligence out in their field devices that they can bypass PLCs and traditional networking entirely.
So, the question remains: Who really is helping end users and who is appearing to help but is actually part of the problem? Each of us must answer this question for ourselves. There are only two kinds of important people in this worldĀthose who are suffering and those who are helping them. The rest of us are just breathing, digesting and existing, sort of.
