The title of this article ends with a question mark. Does this mean that, in light of the ongoing development of overarching concepts and system solutions, the very relevance of sector solutions designed to take account of specific process automation needs and circumstances is in doubt?
Although standardisation certainly has its advantages, for example from a financial point of view, such doubts are not necessarily justified, even given the clear evidence around today of the positive effects of the trend towards universal system concepts in measurement, automation and control engineering. Various aspects of this issue are explored in the following.
Sector-specific user market
Sector-specific solutions for process automation have a crucial part to play in meeting user requirements. It is true that the corporate goals of different sectors, when viewed as a whole, reveal a common interest in economy, safety, ecology, technology, information and quality. But despite this, the user, with his specialist process expertise and, in many cases, years of practical experience in using dedicated systems, expects customised automation solutions for his sector. And today, more than ever, he has good cause to expect solutions tailored to specific needs. That is because the market has been utterly transformed from a producer market to a user market. Of all the manufacturers vying for the user's business, it will be the one who is most familiar with the special needs of the user who will win the contract. Only sector knowledge can enable a manufacturer to provide the functionality the user needs to get the right results. The manufacturers who do best are those who can offer the best compromise between broad-based solutions and specific application needs.
However, this certainly does not mean developers, manufacturers and planners of automation systems have to devise new systems, devices and solutions from scratch for each sector. The current cross-sector trends in hardware and software and in the engineering process open up ideal opportunities for standardisation - as the following paragraphs demonstrate. Special solutions can be developed with little additional effort and therefore at reasonable cost which, even when produced in relatively small numbers, perfectly meet sector-specific requirements.
Hardware
PC-based solutions play an important role in hardware standardisation as far as the information processing aspect of automation systems, rather than the measurement or actuation side, is concerned. The PC mass market is a driving force in this, bringing increased performance along with lower prices. The winners are, among others, users of soft-PLCs who benefit not only from the standard hardware platform (PCs), but also from the open standards prevailing among soft-PLCs. Criticisms concerning the increased use of PCs in industrial automation are gradually being resolved now that the reliability, realtime capability and performance of PC systems are being improved. Although the cost advantages of PC technology have to be weighed up against their potentially shorter life expectancy than normal PLCs, the worldwide availability of spare parts, low training costs and uniform standards in the case of scada and visualisation systems already made for PCs are all plus factors associated with PC use.
Obviously, hardware standardisation as illustrated here with reference to PC-based systems does not inhibit the development of sector-specific solutions. On the contrary, this openness has been behind the high level of success in meeting specific requirements.
Software
In control engineering, open, object-oriented standards such as OLE (object linking and embedding) and CORBA (common object request broker architecture) are facilitating the development of modular-type software solutions. Direct interaction with typical office software is guaranteed, and company-wide data consistency and data availability are made possible. It is important for component software, which is making its mark in the automation sector too, to be reusable, distributable and easy to replace. OPC (OLE for Process Control) software technology makes exchanging data as easy as using the Windows clipboard. Special drivers for swapping data between different programs and applications are no longer required.
As in the case of hardware, the shift towards operating systems like Windows NT, Windows CE and Embedded NT illustrates the key influence of unofficial standards in general computer engineering on automation engineering. The same applies with regard to the advance of Internet/intranet and www-driven technologies like browsers and applets, destined to play a major role in the operating and monitoring of automated processes in different sectors in the future.
The IEC 61131-3 standard (Programmable Controllers Part 3: Programming Languages), as a standardised programming model for industrial control systems, offers users considerable savings potential, as it enables source code for control systems from different manufacturers to be exchanged. This standard has also been instrumental in enabling PLC and PC-based systems to be interlinked. Frequently recurring control system functions can be collected in sector-specific libraries built up according to information system data models. So-called function block models are proving particularly popular in automation engineering right across industry. Fieldbus and IEC standardisation activities are underway in this context. So control system programming now extends to the configuration of function block networks.
Even these few examples from the software field show how general, overreaching trends in automation engineering can create a potentially successful, conceptually unified platform for the development of sector-specific solutions.
Industrial communications systems
The years of struggle towards fieldbus standardisation are an indication of the difficulty of reconciling the requirements and interests of different user sectors and groups of automation systems manufacturers. Manufacturers' requirements aside, there remains the problem of differing technical, sector-specific demands with regard to data transmission at field level. The differing demands vis-à-vis realtime behaviour, bridgeable distances, synchronisation, reliability, safety, explosion protection - to name just a few examples - warrant the coexistence of several fieldbus standards. The drawing up of sector profiles, as practised for various fieldbus systems, creates the necessary basis to enable the required coupling of intelligent field devices - going beyond physical data transmission - to take place and to enable individual fieldbus systems to be engineered. In some user sectors (eg electricity, gas and water distribution), remote control systems have been set up which have a certain degree of autonomy and are only gradually being replaced by other, standardised data transmission solutions.
On the other hand, the trend towards using Ethernet data transmission based on TCP/IP in the hierarchical communications structures of automation systems is evident across the board. Only time will tell how the roles will be divided between fieldbuses and Ethernet in the future.
Engineering
The modelling and description of the components and data of an automation system are of vital importance in the engineering process. In plant engineering, for example, the procurement of automation system components is made much simpler and ordering is streamlined when standardised product descriptions can be used. Even now, it is still often necessary to enter product data several times simply to make it accessible through different software systems and for different purposes (eg asset management), but this is becoming increasingly infeasible for reasons of time and cost. That is why standards like STEP (Standard for the Exchange of Product Model Data, ISO 10 300) for the exchange of product descriptions are attracting growing interest. The STEP standard mentioned by way of an example has already come into use, to varying degrees, in certain sectors. The motor industry is leading the way as far as this is concerned, while in process engineering, the standard is only just emerging on the scene.
Man/process communications
Whatever the sector, responsibility for correct operation of a production process ultimately rests with human beings. The most pressing objectives are ensuring optimal involvement of people in production activities, operational controllability in all situations, maximum up time for production equipment, achieving the desired product properties and ensuring that plants are constructed and run in a cost-effective manner. As a result, as far as the plant-oriented man-machine interface is specifically concerned, process-oriented man-process communications systems are being developed whose central task is to provide structured, relevant information for all people involved with the production process.
As all process information - even in semantic form and with non-metric scaling - is meant to be used in creating man-process communications, it is essential to take a differentiated approach for each process or sectors. Process expertise and information structuring are considered more valuable than individual and, perhaps, random use of the general visualisation facilities of modern process management systems. Furthermore, there needs to be much more of an effort to integrate operator experience as regards process and sector-specific operations into the operating and monitoring concepts.
The performance capability of modern object-oriented visualisation tools can be just as helpful, if not more so, for process-oriented functions, as for a highly detailed representation of the production facilities. The same applies to the use of the rapidly unfolding opportunities offered by man-computer interfaces such as virtual and augmented reality systems, recognition of the gestures, head and eye movements of the operator or haptic feedback in the case of input devices, eg by power feedback or transmission of vibrations.
Conclusion
As this by no means comprehensive survey of different aspects of 'Sector-specific solutions for process automation' has shown, the question cannot be answered with a clear-cut YES or NO. A trend towards standardisation is emerging in certain sectors and is already well advanced in some cases, driven by economic imperatives. On the other hand, it is precisely the process-oriented, and consequently the sector-oriented features which ultimately determine the success of a solution. For this, technical, sector-specific and company-specific requirements all have to be taken into account.
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