-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 95 www.windmill.co.uk June 2006 --------------------ISSN 1472-0221---------------------- Welcome to the midsummer issue of Monitor (at least it is here in the Northern hemisphere). We hope you enjoy it, but should you wish to cancel your subscription you can do so at http://www.windmill.co.uk/newsletter.html CONTENTS ======== * Windmill News: Counting Passengers on Public Service Buses * Windmill Notes: Getting Started with the Windmill 6 Serial Package * Choosing the Right Range and Resolution * DAQ News Roundup ________________________________________________________ ________________________________________________________ Windmill News: Counting Passengers on Public Service Buses ________________________________________________________ 21st Century Crime Prevention Services Limited are using Windmill's VT Collect software to count passengers entering and leaving a vehicle. The information collected will be interfaced with fare revenue data from the ticketing machines. Eventually the system will automatically transmit an audit report back to the control centre as each bus returns to its depot. The company expects that the system will give greater control on revenue and reduced running costs for bus operators up and down the country. ________________________________________________________ ________________________________________________________ Windmill Notes: Getting Started with the Windmill 6 Serial Package ________________________________________________________ Lets imagine you've installed the Windmill 6 software to interface RS232, RS485 and Modbus devices to your PC. (https://www.windmillsoft.com/daqshop/rs232-modbus.html) What do you do next? 1. Run ComDebug. 2. Follow the steps in our Getting Started with COMIML section. (Or click the ComDebug Help button and go to the Getting Started section there.) 3. Run ConfIML and add the "COMIML Serial Instrument Handler". 4. Run SetupIML and give names to your data channels, set measurement units, signal ranges, etc. 5. Run Chart, Logger or one of the other Windmill programs and start to read and display data. 6. If you wish, transfer the readings to Excel. What about in future? 1. Skip steps 1 to 4 above and go straight to using the Windmill logging, charting, display and control programs. All the Windmill programs have Help files associated with them. You can download the latest versions of these Help files from http://www.windmill.co.uk/help.html For more on transferring data to Excel see http://www.windmill.co.uk/excel/ ________________________________________________________ ________________________________________________________ Choosing the Right Range and Resolution ________________________________________________________ Most analogue sensors produce a voltage, including thermocouples, strain gauge bridges and gas concentation probes. This is converted to a form the computer can understand by an analogue-to-digital (A-D) coverter. The input range (or gain range) of an A-D coverter refers to the maximum and minimum voltage that it can accept. An input range may be bipolar, covering a range from -50 mV to +50 mV for example; or unipolar, perhaps covering a range of 0 to 50 mV. Many A-D converters have an actual range of 0 to 10 V, so an input signal with a range of 0 to 50 mV needs to be amplified by a gain of 200 before it can be converted. Many systems offer a choice of ranges, and you can select the most appropriate using software like Windmill. You should always choose the smallest range that encompasses your signal, as this optimises the resolution. The resolution is the number of steps into which the input range is divided. The resolution is usually expressed as bits (n) and the number of steps is ((2 to the power n) - 1). This equates to (2 to the power n) values. A converter with 12-bit resolution, for instance, divides the range into 212, or 4096, values. In this case a 0-10 V range will be resolved to 2.5 mV, and a 0-100 mV range will be resolved to 0.025 mV. Although the resolution increases when you narrow the range, there is no point in trying to resolve signals below the noise level of the system: all you will get are unstable readings. Some A-D converters have a choice of resolutions (offering 12-, 13-, 14-, 15- and 16-bit for example). You can choose the most suitable for your application, balancing speed against accuracy. For more data accquisition tips and techniques, see the Windmill web site at http://www.windmill.co.uk/ ________________________________________________________ ________________________________________________________ DAQ News Roundup ________________________________________________________ Welcome to our roundup of the latest findings in data acquisition and control. If you would like to receive more timely DAQ news updates then grab our RSS newsfeed at https://www.windmillsoft.com/monitor.xml. Read http://www.windmill.co.uk/newsfeed.php for information how. Virbration Monitor provides Landslide early Warning A device that provides early warning of a landslide by monitoring vibrations in soil is being tested by UK researchers. The instrument comprises a steel pipe dropped into a borehole in a slope. The borehole is filled in with gravel around the pipe to help transmit high-frequency vibrations generated by particles within the slope. These vibrations pass up the tube and are picked up by a sensor on the surface. Software analyses the vibration signal to determine whether a landslide may be imminent. Source: New Scientist http://www.newscientisttech.com/ Temperature Sensitivity Identified in Circuit Boards Electrical circuits may act differently in cold climates than they do in warm - potentially affecting the performance of computers and other electronics. A new technique identifies and quantifies an important cause of this temperature sensitivity. Source: National Institute of Science and Technology https://www.nist.gov/ Substantial Growth Predicted for Wireless in Automation The world market for wireless communications in automation is forecast to grow at 28 percent per year over the next 5 years, according to IMS Research. Wireless communications is not widely used within the automation environment at present, but a proliferation of new products is being introduced currently. Source: IMS Research http://www.imsresearch.com/members/pr.asp?X=258 Extra-Sensitive Touch Sensor Developed An artificial touch sensor as sensitive as a human fingertip has been developed by US scientists. To make the sensor researchers deposited alternating layers of gold and cadmium sulphide nanoparticles, separated by insulating layers of polymer. They then applied a voltage across the film. As a result, when pressure is exerted on the material its layers squeeze together allowing current to flow. As the current flows through different regions of the material it causes the cadmium sulphide nanoparticles to emit light, creating an image that can be picked up by a digital camera. Source: New Scientist http://www.newscientisttech.com/ ________________________________________________________ ________________________________________________________ * Copyright Windmill Software Ltd * Reprinting permitted with this notice included * For more articles see http://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 http://www.windmill.co.uk/newsletter.html and an index of articles at http://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] http://www.windmill.co.uk/ https://www.windmillsoft.com/
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