Wireless signals stronger

Wireless remains a "hot" topic at the moment, but how confident are process engineers when it comes to recommending a wireless transmitter as a viable answer for their next measurement challenge? Market watchers report that concerns over security and reliability persist, though there are also signs that confidence in - and openness about - the technology is increasing.

There has, for instance, been a steady increase in the volume of case studies and application stories issued by vendors - with the consent of their customers - over recent months. These include projects at; E.ON's Kingsnorth power station in the UK, BP's Wytch Farm on-shore oilfield, also in the UK; Total Petrochemicals' Carling site in France; StatoilHydro on the Grane offshore platform, near Bergen, Norway; Hexion Chemical's polymer plant and the Standic storage and distribution centre - both in The Netherlands.

Wireless installations on existing plants are apparently being justified on cost because of the difficulty of installing new cables on existing sites, or to overcome wiring problems. The systems generally provide low response rate monitoring signals, but the reliability is proving good, and some slow response control applications have been commissioned.

New site installations are incorporating further facilities, such as employee location, voice and video communication, to expand the capabilities offered. Possibly of more interest to existing plants, once a wireless network is available, further sensor systems to monitor corrosion, or vibration, or multiple sensors giving more detailed process information, are becoming available, to enable plant and process efficiency monitoring that was not previously justifiable.

Everything in the reports published to date indicates that there should be no hesitation in recommending wireless systems on process applications, particularly for retrofit installations and expansions on tank farms and monitoring systems - though, it should be asked, is anyone going to report on the systems that did not perform properly?

Nevertheless, in a recent supply-side report, US market analysts at Venture Development Capital Research suggested that wireless networking systems as a whole - as opposed to measurement sensors - have overcome the initial concerns of major user regarding security.

VDC forecasts the worldwide market for industrial infrastructure wireless networking products to increase at a compound annual growth rate of 25.4%, to reach $928 million by 2012 - despite prevailing economic conditions. The US firm also identifies the process sensor sector as the area likely to show the most growth over the next five years, exceeding 50% pa.

"Wireless has overcome many of the initial concerns regarding security and the perception is now that it offers ease of implementation, and lower maintenance and installation costs," stated Jim Taylor, director at VDC.

According to VDC, the majority of global wireless networking product shipments are for devices with wireless Ethernet (IEEE 802.11 standards) connectivity. Proprietary protocols account for the second largest share of shipments and in 2007 held 37% of the global infrastructure market for the products under study. A shift towards use of standard networks is expected, but shipments with proprietary networks are forecast to still account for over 29% of the market in 2012.

"Even though many suppliers suggest that security is an application concern not a technology concern, there is still a perceived notion that proprietary networks are more secure than standard types," explained Ladd Bodem, practice director at VDC.

Conversely, Frost & Sullivan believes that the rate of wireless adoption is still being hampered by concerns among end-users, namely "reliability, security and safety". It notes that the process industry in Germany is reported to be slower than other areas of the EU in adopting wireless systems, and notably slower than the UK.

In the factory automation arena, a recent report by IMS Research forecast an almost ten-fold growth in such device shipments over the next six years, an annual growth rate of 40%. The biggest obstacle to adoption by machine builders and factory automation end-users quoted is that of 'perceived reliability'.

With falling wireless price levels, IMS acknowledges that there are major process efficiency improvements possible on some plants by applying wireless technology and adding measurement sensors. These opportunities, it suggests, are found much more in larger process plants than in smaller manufacturing facilities also included in its definition of factory automation systems.

Confidence in wireless adoption also clearly depends on the nature of the application involved, adds Paul Lazor at Extronics, pointing to the limited impact of WLANs in certain industrial manufacturing environments. In particular, he said, take-up of such systems within hazardous environments where flammable gases, vapours or dusts are present has been very slow.

"One of the key reasons why WiFi has not been deployed in Ex areas has been the lack of practical user applications, as well as limited suitable handheld PDAs with good battery life and screens. The latest generation of such devices has addressed these issues," said Lazor.

According to the Extronics man, initial responses to WLANs has been greeted with many misconceptions based upon concerns about the use of radio frequencies within hazardous areas, security issues relating to malicious attack - although security has improved with the introduction of the WPA2 standard for user authentication - and effectiveness in densely populated steel-structured environments.

"It is only recently that limits for RF transmissions have been established and suitable explosion protection techniques ratified and put into the type approval standards. Advanced encryption techniques have been developed to increase security and optimise the performance of access points on plant," he noted.

On the other hand, Lazor believes that today's turbulent economic climate demands massive increases in efficiency and reduced operational costs. This will probably prove to be the most effective driver in delivering wireless applications to plants where high cabling costs are prohibitive to expansion.

"The scalability of a WLAN to embrace many applications from mustering to CCTV, voice, asset management and process control through data transfer will provide the metrics for value proposition to bring about a rapid uptake of this important technology sector," commented Lazor.

Another (supply-side) take comes from Hesh Kagan, of Invensys Process Systems, who believes that the adoption of wireless has followed the geographic spread of the enthusiasts and technology champions among the vendors. The suggestion here is that no process plant user will invest in the technology until visible and knowledgeable vendor support is available locally.

Kagan noted particular interest in new wireless condition monitoring sensors, which are being introduced for retrofit onto existing plant to improve asset management. Likewise, he said, the market is keen to apply the wireless corrosion sensors that are emerging for long-term monitoring of pipes and plant facilities.

The IPS expert, however, concluded that for wider acceptance of wireless to happen, more information on developments surrounding the technology, as well as case studies and application stories must be circulated by trade bodies, manufacturers and the press.