Though there is still apprehension among users about the security and safety of wireless connected sensor and control components, these issues have long been addressed and the technology does now have an awful lot to offer. Many of the old limitations and complexities of point-to-point, mechanically interconnected instrumentation systems no longer apply. Users can now choose wireless devices for a host of applications and gain a freedom and flexibility of system design and installation that was not previously possible. One company that has embraced wireless technology with enthusiasm is Manchester based Omega Engineering (http://www.omega.co.uk/), which now boasts an extensive product range, from which the user can pick and choose in order to build a complete system. The process is simple and you don’t have to be a wireless expert to get your system up and running. Complementary Ethernet and Internet servers are also available to combine with Omega’s sensors, making it possible to connect, monitor and control any process parameter from anywhere in the world. A good starting point is to take a look at the company’s ‘New horizons in wireless communications’ book, a 65-page publication featuring wireless enabled transmitters, receivers, loggers, recorders, controllers, systems and sensors. And if you do need it, there’s full technical support and application assistance available from the in-house engineering team. The book is free to download from http://www.omega.co.uk/ or simply email your details to firstname.lastname@example.org A good example of how wireless connectivity can be applied to an existing wired HVAC controls installation, is to be found at the head office of the Bedford Pilgrims Housing Association in Bedford. The new installation, completed by Northampton-based systems integrator AES Control Systems using wireless sensing technology from Sontay (http://www.sontay.com/) will help improve energy efficiency, reducing carbon emissions for the housing association, and also bring greater building use flexibility for many years to come.Temperature regulation, in particular, had been a huge issue for the facilities manager, who needed to improve efficiency while minimising installation cost and disruption to the day-to-day operations of the Association. AES Control Systems identified the wireless option as the best means of overcoming any problems, and specified Sontay’s SonNet wireless sensor system as the least disruptive solution.Following a site survey to prove that the equipment would work correctly, prior to installation, the installation went ahead. One SonNet receiver runs a network of sensors alongside one router on each floor of the building. These sensors measure internal temperature and solar gain of the building, helping to regulate the HVAC services for optimum efficiency. The need for structured cabling to these devices was completely eliminatedAs the sensors operate wirelessly, they can be easily and cost-effectively re-located, or new sensors added, should office layouts and the requirement for temperature measurement change over time.The SonNet radio receiver is available with 20 channels, as standard, and up to 40 with the addition of an optional 20-way daughter board. For maximum reliability, operation and battery life, the sensors run a self-healing tree application, so it is effectively a ‘fit and forget’ communications installation. The sensors offer a battery lifetime of up to five years and are available in a number of variants, catering for space, immersion, duct and outside air monitoring.Most of us are aware of the big analogue to digital TV switchover, which is being rolled out across the UK and is due to complete this year. Well, the project has release a substantial radio spectrum – the so-called TV white space spectrum – which is being picked up for various commercial uses. One company that has been fast off the block is Neul (http://www.neul.com/), which recently launched the world’s first production white space radio system delivering up to 16Mbps over distances of up to 10km.NeulNET promises to revolutionise machine-to-machine (M2M) communications, local broadband delivery, smart meter communications and the ‘Internet of everything’. There is up to 150MHz of high quality white space spectrum available. To put this into perspective, typical nationwide 3G networks operate with a mere 30MHz of spectrum, and while 3G spectrum costs literally billions of pounds to licence, white space spectrum will be available free of charge.To use white space, however, systems must meet very stringent technical specifications to prevent interference with television equipment and wireless microphones. NeulNET is the first wireless system to meet these conditions, including the FCC’s challenging adjacent channel power specification.M2M communicationThere are already over 200 million M2M devices and this number is rising with a 23% compound annual growth rate. But the M2M market is set to explode, with applications such as in-car navigation, telematics, retail electronic point-of-sale and others. The number of connected devices is expected to reach 50 billion by 2020 – a network often referred to as ‘the Internet of everything’.In-Stat research director and keen observer of M2M and white space trends, Allen Nogee says modems using cellular (2G and 3G) technology are too expensive for many M2M applications, as well as consuming too much power. “Neul’s very novel M2M solution, using available white space spectrum, is perfect for those applications requiring a low-cost, ultra-reliable connection that consumes very little power and supports very high device densities and capacities,” he adds.NeulNET is based on a new wireless standard called ‘Weightless’ and Neul is working with industry leaders to develop Weightless into an open, royalty-free standard. The specification will ultimately become available to companies interested in developing M2M products through membership of the Weightless Special Interest Group (SIG).The ZigBee wireless standard, meanwhile, goes from strength to strength. Derby based IDC (http://www.zig-bee.co.uk/), which specialises in logistics, product tracking systems and manufacturing control, has expanded its ZigBee low-power wireless network products, in terms of range, network size and security, with the introduction of the new ZB109 router.Designed for operation with IEEE 802.15.4/ZigBee wireless sensor networks, the ZB109 provides redundancy in the event of a router failure. Up to 100 of the devices can be deployed in a wireless network using a single IDC ZB103/4 Gateway, the routers providing a range of up to 100m line-of-sight with a 2.1dBi antenna, or much increased distances up to 250m with an optional 8.5dBi antenna. It extends the range and strength of 802.15.4 wireless mesh networks, at the same time creating additional network paths to improve network reliability.It works for inspection too!For some time Flir Systems’ (http://www.flir.com/) customers have been able to extend the scope and depth of thermal imaging inspection with features based on wireless technology. Users have reported efficiency gains, error reduction and time savings through WiFi compatibility and the use of Meterlink technology (a technology that enables the transfer, via Bluetooth, of data acquired by an Extech clamp meter and embedding it in the thermal image).Now the company is applying these features to even more of its cameras, enabling them to transfer radiometric images via WiFi to an iPad or iPhone as a standard feature. This capability allows data to be shared with colleagues, who not only see the images, but are also able to analyse them directly on their iPad or iPhone thanks to the downloadable Flir Viewer app.Now what do you do if you want to combine a new wireless network with an existing wired installation; in particular, one that is connected over a conventional fieldbus? Buckinghamshire based Deeter Group (http://www.deeter.co.uk/) has one solution in the form of its new wireless Modbus gateway. Users of Modbus communication protocols can apply the new gateway between a Deeter wireless sensor network and a Modbus system to monitor physical or environmental conditions, such as liquid levels, temperature, humidity, vibration, pressure and proximity. The unit communicates with the Modbus network via a RS485 port in slave mode. It co-ordinates the wireless sensor network and manages data acquisition from the sensors using the IEEE 802.15.4™ wireless protocol in the 2.4GHz ISM frequency band. It can be installed as a component of a new control or measurement system or as an extension to an existing wired sensor system in order to add wireless connected sensors.As Deeter’s Alan Marsh, comments, Modbus has become one of the most popular standard communications protocols used in process control and is now amongst the most commonly available means of connecting industrial electronic devices. “Our new Modbus Gateway will allow customers to integrate Deeter Wireless Sensor products into existing or new control systems in locations where wireless has cost, safety and convenience advantages over conventional cable connected systems,” he says.Deeter wireless products may be used indoors or outside and all are rated to IP64, have an operating temperature range of -20ºC to +70ºC and are compliant with FCC part 15. The wireless sensor networks are very versatile and can range from a simple single sensor measurement to complex multi-sensor and multi-vendor systems with mixed sensor inputs, plus routers to extend wireless range, and offer self-healing mesh networks.
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