-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 110 www.windmill.co.uk September 2007 --------------------ISSN 1472-0221---------------------- Thanks for continuing to subscribe to Monitor. This month guide to the different types of wireless networks you could use for data acquisition. I hope you enjoy the newsletter but should you wish to cancel your subscription you can do so at https://www.windmill.co.uk/newsletter.html CONTENTS ======== * Windmill News: People counting help * Logging data wirelessly * Excel Corner: Adding several y axes to a chart * DAQ News Roundup ________________________________________________________ ________________________________________________________ Windmill News: People Counting Help ________________________________________________________ You can now download the latest Help file for our people counting software. Called VT Setup, the software improves the accuracy of counting people into and out of buildings. It lets you tailor the system to suit each individual doorway and can handle hundreds of entrances. To download the new Help file go to https://www.windmill.co.uk/help.html You need to unzip the files before you can use them. In Windows double-click the vtsetup.zip file and from the File menu choose Extract All. For more on counting people see http://www.retailsensing.com/ ________________________________________________________ ________________________________________________________ Logging data wirelessly ________________________________________________________ Monitoring instruments and sensors wirelessly is becoming more and more common. A wireless network saves cabling costs and installation time. It is useful in electrically noisy or hostile environments. It lets you move your measuring device from place to place and remotely monitor conditions. You can log data from your existing devices wirelessly by adding appropriate adaptors or routers. There are several different methods of wireless communication. The standards for many of these methods are still being developed. Bluetooth Bluetooth was designed as replacement for short-range cables. It allows up to seven devices to be monitored over short distances, typically about 10 meters. It is called a wireless Personal Area Network (PAN) and conforms to the IEEE 802.15 standard. It is suitable when devices are close to the computer and high bandwidth is not required. You can use Bluetooth to log data from RS232 instruments by plugging a Bluetooth radio adaptor into your PC's COM port and one into your instrument. You can then use software like Windmill's COMIML to collect data (https://www.windmillsoft.com/daqshop/rs232-modbus.html). Bluetooth is named after a Danish king who unified Denmark and Norway. Further reading: http://www.bluetooth.com/ Wibree (Ultra Low Power (ULP) Bluetooth) Wibree is a new interoperable radio technology for small devices like sports sensors. It was designed by Nokia for applications where ultra low power consumption, small size and low cost were the critical requirements. In June this year it was decided that Wibree would be included in the Bluetooth specifications and renamed Ultra Low Power (ULP) Bluetooth. Further reading: http://www.wibree.com/ WiFi Similar to a traditional Ethernet model, WiFi comprises a local area network (LAN). It uses the same radio frequency as Bluetooth, but with higher power consumption. WiFi is preferable to Bluetooth for operating medium-to- large networks because it allows for a faster connection speed, greater range, more devices to be monitored and higher security levels. For more on WiFi and data acquisition see Issue 82 of Monitor, https://www.windmill.co.uk/monitor82.html ZigBee ZigBee was designed specifically for remote monitoring and control. It comprises a personal area network based on the IEEE 8-2.15.4 standard. ZigBee can support thousands of nodes in a star or mesh network. In a star network all devices communicate with the controlling node, as is used by WiFi and Bluetooth. In a mesh network, messages can be passed from node to node such that if any of the nodes fail, the message can still reach the destination. Once associated with a network, a ZigBee node can wake up and communicate with other ZigBee devices then return to sleep. This and its low power means that a device's battery can last a very long time. Further reading: http://www.zigbee.org/ WirelessHART Passed earlier this month, the HART 7 specification includes the wireless protocol dubbed WirelessHART. This sets out to create a wireless version of the Wired HART protocol in order to ensure backward compatibility with wired devices. HART Communication is used to communicate between intelligent field instruments and host systems. Further reading: http://www.hartcomm.org/ WiMax WiMax, the Worldwide Interoperability for Microwave Access, aims to provide wireless data over long distances in a variety of ways. It is based on the IEEE 802.16 standard, which is also called WirelessMAN. Typically it has a range with a radius of 3 to 10 km. The WiMAX Forum expects the technology to allow city- wide wireless broadband access. In the data acquisition field, WiMax is envisaged as most useful for monitoring offshore facilities. Further reading: http://www.wimaxforum.org/ GPRS and GSM GSM (2G) networks are used for voice calls from mobile (cell) phones. They are limited when it comes to sending or receiving data as it can take up to 30 seconds to make a connection to the network. GPRS is a method of enhancing GSM. GPRS (General Packet Radio Service) devices can transfer data immediately and at higher speeds. GPRS uses the existing GSM network to transmit and receive TCP/IP based data to and from GPRS mobile devices. GPRS devices are always on, as opposed to dial-up modems. You can connect Ethernet devices to a GPRS network by adding a suitable GPRS router. More Wireless Resources: IEEE Wireless Standards Zone The IEEE is developing open, consensus standards for wireless networks. http://standards.ieee.org/wireless/index.html ISA-SP100 The ISA-SP100 group formed in 2004 with the charter to establish standards and recommended practices for implementing wireless systems in the automation and control environment, with a focus on the field level. https://www.isa.org/ ISA: Users fear wireless networks for control https://www.isa.org/ ________________________________________________________ ________________________________________________________ Excel Corner: Adding several y axes to a chart ________________________________________________________ We were asked this month how to plot 3 variables on an Excel chart, each with a different y axis. Excel doesn't offer an option to do this, but there are work-arounds to achieve it. On way relies on using a dummy chart series to add a third axis. This was pioneered by Jon Peltier. He describes the method at http://peltiertech.com/Excel/Charts/TertiaryAxis.html The second method is to display traces separately, like the Windmill Chart program doesThis is also known as a panel chart, a trellis chart, a stacked line chart or a multi-plot chart. Details of how to achieve this in Excel are given at Jon Peltier's site at http://peltiertech.com/Excel/Charts/StackedCharts.html For more on data acquisition and control using Excel see https://www.windmill.co.uk/excel/ https://www.windmill.co.uk/excel/excel-charting.html ________________________________________________________ ________________________________________________________ DAQ News Roundup ________________________________________________________ Welcome to our roundup of the data acquisition and control news. If you would like to receive more timely DAQ news updates then grab our RSS newsfeed at https://www.windmillsoft.com/monitor.xml. Read https://www.windmill.co.uk/newsfeed.php for notes on how to display the news on your own web site, read it via e-mail, mobile phone or a newsfeed viewer. Ear-sensor helps athletes A new body sensor, the size of a hearing aid, monitors the performance of an athlete while training. The sensor fits behind the ear and gathers data about posture, stride length, acceleration and response to shock waves travelling through the body. A computer inside the earpiece and transmits data to a laptop for real-time monitoring of athletic performance. Source: Imperial College http://www1.ic.ac.uk/medicine/news/p71309/ NIST measures challenges for wireless in factories Heavy industrial plants are challenging environments for wireless systems. They can be highly reflective, scattering radio waves erratically, and interfering with or blocking wireless transmissions. NIST have identified a number of steps to take minimise radio interference on the factory floor. Source: National Institute of Standards and Technology https://www.nist.gov/public_affairs/techbeat/ Smart homes could track your electrical noise Your computer could one day track your movements around the house by monitoring the electrical noise made by household appliances as you switch them on and off. Such a system could be cheaper and simpler to operate than the suite of sensors that researchers currently envisage for "smart homes". Source: New Scientist https://www.newscientist.com/ Beyond Batteries: Storing Power in a Sheet of Paper Researchers at Rensselaer Polytechnic Institute, New York, have developed a new energy storage device that easily could be mistaken for a simple sheet of black paper. The battery is lightweight, ultra thin, completely flexible, and geared toward meeting the trickiest design and energy requirements of tomorrow's devices. Source: Rensselaer Polytechnic Institute http://news.rpi.edu/update.do?artcenterkey=2280 ________________________________________________________ ________________________________________________________ * Copyright Windmill Software Ltd * Reprinting permitted with this notice included * For more articles see https://www.windmill.co.uk We are happy for you to copy and distribute this newsletter, and use extracts from it on your own web site or publication, providing the above notice is included and a link back to our website is in place. An archive of previous issues is at https://www.windmill.co.uk/newsletter.html and an index of articles at https://www.windmill.co.uk/newsletter.html Windmill Software Ltd, PO Box 58, North District Office, Manchester, M8 8QR, UK Telephone: +44 (0)161 833 2782 Facsimile: +44 (0)161 833 2190 E-mail: [email protected] https://www.windmill.co.uk/ https://www.windmillsoft.com/ Do you have a question, comment or suggestion on this newsletter? 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September 2007
