This year's Hannover Fair was again a huge and impressive event for industry. As such, it does not focus on control and instrumentation as does Interkama, but exhibits factory automation, micro-technology, energy technology, and R&D among other technologies, and provides numerous topical conference presentations. In this broad industrial showcase, one sees how widely technologies often more associated with process instrumentation are used in mechanical systems.
In some areas, the mechanical applications may drive developments in control and instrumentation; for example in sensors, and in the proven adoption of PC concepts in PLC design, with integration into such microcontrollers of various buses, Ethernet, web-accessibility, both standalone and built into machinery. Manufacturing machines are using bus concepts more, facilitating transportability of machines as plug-together modules, and also enabling more extensive advanced diagnostics. As with IT, scada systems can be seen everywhere (and growing in demand according to new vendors on show) as it becomes more accessible and affordable in smaller machine automation applications. And, hidden within, are modern non-linear control engineering designs, which result in faster cycle times and more accurate control.
The Hannover Fair emphasises the remarkable convergence of advancing technologies, and the cross-pollination between disciplines. Control and instrumentation practitioners have always been positioned in a multidisciplinary mix, that's nothing new. But what is new, is the higher rate of development and the breadth of converging fields; and it again raises the question of whether we are adequately equipping our trainee control and instrumentation mechanicians, technicians, technologists and engineers with the appropriate skills. And are facilities sufficient for the renewal of skills of the 'old school'? (Who have very limited time for training.)
The SAIMC's Education group will continue to address the skills issues, and we support training bodies with time, experience, equipment and funding, with your vital support. I will report back on how we progress this year.
Fieldbus was a topic addressed at the recent Process Exhibition at Kyalami, with one presentation given on Foundation Fieldbus and one on Profibus.
Question from the audience:
"Why don't the industry and suppliers sit together and decide on a single standard?" Good question.
It is not easy, and has been attempted since the 1980s, which at least led to the creation of a limited number of standards. But the diversity and number of suppliers (for example, compare the number today of DCS and PLC manufacturers with 10 years ago), the leap-frogging of technology, and need for backward compatibility, made this a highly complex issue.
The number of fieldbuses increased rapidly nevertheless, and today we have approximately 18 major names. In around 1990, four standards bodies, American (ISA), European (IEC), German (Profibus) and French (FIP) formed a committee to create open standards both for the interfaces of field devices and for a new communication protocol, IEC/ISA SP50. Then, basically in line with this protocol, two groups representing most of the industry's major stakeholders (ISP, and World FIP) formed in 1992, and in 1994 they merged to become the Fieldbus Foundation (FF), still with the aim of an open standard. Since then FF has gained credibility and momentum, as seen in the agreement this April with Honeywell and Emerson (Fisher-Rosemount), giving FF access to certain technology and patent rights. So perhaps this is leading to an answer to the question from the audience, but do not hold your breath, for in the list of the 29 worldwide manufacturers of instrumentation to FF spec, there are still some glaring absentees.
My visit to the Process Exhibition was worthwhile, and I was interested to see how flow measurement is advancing in accuracy, ease of use and 'total cost of ownership'. One example was in the chemical industry where we used to measure custody transfer of liquid ammonia by a high-precision special standards-calibrated turbine meter. But readings were occasionally erratic (due to minute temperature changes, and maybe flashing and turbulence); the 'owners' on each side realised the huge value implications of inaccuracy, even when as low as 0,05 to 0,1%. So, in went another, second hi-spec turbine meter (in today's money costing about R90K installed), and longer straight lengths of pipework (more cost). But, guess what, the two meters disagreed, of course, and the two 'owners' became more irate, each concerned that he was being short-changed. So, what better to do than install a third meter! This temptation we resisted, and an average of two readings won the day, providing they were consistent. And we rotated the two installed meters, with a spare to have them recalibrated overseas, at intervals. This is a pretty high total cost of ownership!
Now we see at the exhibition a multiple-sensor ultrasonic meter, used in fuel transfer, which compensates for changing flow/velocity profile and is claimed to achieve 0,05% and better. It must make life somewhat easier and less costly!
Also interesting were the newer zero-leakage steel-to-steel sealed rotary valves, built-in acoustic leak detection in valves, and smarter positioners. On the show was a South African-built gas-detection, networking and scada system for mines, which has a sizeable installed base locally and is adding to mine safety.
Lastly, one more 'plug', the SAIMC branch activities around the country include presentations on technology subjects, both informative and entertaining in a relaxed environment. If you are not an SAIMC member then do consider joining as this is one our way of keeping in touch with developments, learning from other's applications experience, contributing to our industry and meeting interesting colleagues.
Until next month!
Richard Teagle (SAIMC President)
(011) 971 5500
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