Wireless communications have well and truly arrived in the industrial arena and considerable effort is now being put into integration and the writing of Standards. Paul Gay, independent journalist, considers the many benefits and a few drawbacks of this cost effective technology.
Wireless communication in the industrial environment has become a reality. The technology now offers practical solutions to industrial automation connectivity with the key benefits of cost-saving installation, minimal operating costs and, perhaps most important to the end user, reliability.
Wireless communications are cheaper to install than traditional hard-wired systems because, quite simply, there are no cables. When there's no cable then there are no conduit, wiring racks or digging of underground cable runs – all costly items, especially when the installation is within an existing plant or factory.
Operating costs and maintenance are also considerably reduced as there are no cables to be replaced because of accidental damage or overload. Cables can be destroyed by lightning strikes, power spikes or contact with plant vehicles, such as diggers and lift trucks cutting into them. When control signals are being transmitted on radio signals, none of these physical issues come into play.
Once a wireless network is installed, the cost of adding devices is minimal, making the installation very flexible. The user may require an extra sensor or actuator at the other side of plant. To connect to a traditional hard-wired system would involve running several hundred of metres of cable. With wireless, costs are dramatically reduced.
As with any new technology, there are downsides. The techniques are new to the industrial environment and, therefore, not well understood in many sectors. There are always risks in implementing systems where there is a lack of experience among end users. Perhaps the biggest worry over wireless installation is conflicting standards, because not only are there several quite different technologies available, there are also different organisations working on the Standards that will eventually implement the necessary integration.
The IEC (International Electrotechnical Commission) TC (technical committee) responsible for wireless Standards is TC65: Industrial-process measurement, control and automation. This TC was established in 1968 and writes basic Standards for industrial automation and specific Standards for industry. With its SCs (subcommittees), in particular SC 65C: Industrial networks, and its WGs (working groups), TC65 prepares international Standards for systems and elements used for industrial process measurement and control concerning continuous and batch processes and the integration of elements into such systems.
SC 65C prepares international Standards on wired, optical and wireless industrial networks for industrial-process measurement, control and manufacturing automation, as well as for instrumentation systems used for research, development and testing purposes. The scope of this SC includes cabling, interoperability, coexistence and, most important, performance evaluation.
Continuing expansion of the global market for industrial automation equipment demands further international harmonisation of safety and security aspects, as well as interoperability and easier systems and device integration in multi-vendor environments. Interfaces and generic models are becoming the most important subjects for standardization due to the increased adoption of widely used IT (information technology) solutions and de-facto standards within automation applications. A shift from proprietary to open automation interfaces has the worldwide support of both large and small vendors.
Industrial automation users and suppliers are faced with extremely rapid innovation and high market competition for which the traditional overall consensus-related harmonisation process is often too slow. This is complicated by the long lifetime expected for automation equipment, requiring coexistence of several generations of equipment.
IEC international Standards issued by TC65 and its SCs are used by automation system and device manufacturers, system integrators, and end-user manufacturers. To attract end users for active participation in the standardisation work is a basic difficulty. The publications are widely used at the regional and national levels, but there is still an ongoing risk of overlapping standardisation efforts between the IEC and ISO (International Organization for Standardization) TCs dealing with industrial automation aspects in general.
Today's automation technology also takes into account such issues as protection of the environment and saving of energy and resources in addition to the original aims of controlling production processes in the most economic way and with the highest regard to both safety and quality. Those requirements are addressed by TC65 and its SCs.
The Standards are further complicated by the plethora of protocols that exist to operate the hardware and allow communication over the radio waves.
A future issue of e-tech will look in further detail at the numerous solutions being developed around the world. Simply looking at the impressive list of experts who make up IEC SC65C gives an idea of the extent of their technical knowledge. SC65C calls on over 100 experts in 19 different countries: Austria, Belgium, Canada, China, Denmark, Finland, France, Germany, Italy, Japan, Republic of Korea, The Netherlands, Norway, Russian Federation, South Africa, Sweden, Switzerland, United Kingdom, and the United States of America. In addition, it liaises with some fifteen different institutions.
Reproduced from an article by Paul Gay in IEC e-tech, September 2009.
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