-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 62 www.windmill.co.uk September 2003 --------------------ISSN 1472-0221---------------------- Hello, and welcome to the September issue of Monitor - the newsletter for PC-based data acquisition and control. We only send Monitor to people who have subscribed - should you wish to cancel your subscription please do so at http://www.windmill.co.uk/newsletter.html CONTENTS ======== * Windmill News: Improved Crash Testing for Cars * Excel Corner: Automatically Updating a Chart ________________________________________________________ ________________________________________________________ WINDMILL NEWS: IMPROVED CRASH TESTING FOR CARS ________________________________________________________ Crash testing is essential to ensure passenger safety. The Britax Excelsior crash testing facility at Andover (UK) has two tracks which it uses to test its car and aircraft seats. Recently Britax has conducted a major upgrade to its facility and Windmill Software has been closely involved in this. In order to provide calibration and online viewing of the output from accelerometers, Windmill produced a driver for the Microlink 580 transient capture card that Britax was already using. This meant engineers could now view readings in the Windmill DDE panel. Windmill also modified their Brake Testing application to provide a front end software package that allows the operator to select a particular type of test and dummies to be used. These are associated with particular sensors so that calibration data for each sensor is automatically passed to the analysis program (FAMOS). FAMOS can then give accurate readings of acceleration in g (grav). The setup of the test, data collection during the crash, and analysis according to the test selected are all processed through the Windmill front end software. This maintains records of each test carried out, together with storage of raw data files for later re-analysis if required. FAMOS sequences have been produced that extract the crash test waveforms, filter these according to the international standards, and compare maximum accelerations in 3 axes for head and chest accelerometers, with additional rotational accelerations recorded for neck sensors. FAMOS Sequences have also been provided to calculate the Head Injury Criteria (HIC) which finds the maximum of integrated head acceleration during the crash. For more information contact Windmill Software at [email protected] For more on Microlink Measurement and Control systems see http://www.microlink.co.uk/ ________________________________________________________ ________________________________________________________ EXCEL CORNER: AUTOMATICALLY UPDATING A CHART ________________________________________________________ When using Excel to display data from Windmill in real- time, you may find it useful to also automatically update a chart in Excel. Suppose you wanted to plot data in column A against the data in column B. You could simply insert a chart with the range =$A:$B As the data arrives from Windmill DDE Panel, the chart will automatically update. However, if the rows of data exceed the original size of the worksheet, the chart will stop. You can get round this by using Excel's CountA and Offset functions. CountA gives you the number of non- blank cells in a column. With Windmill data this equates to the number of rows of data (and headings). Offset returns a cell reference according to your settings. Using CountA as the height of the column gives a reference to the bottom row. This reference will automatically update when new data arrives. For example, this is the syntax of Offset: OFFSET(reference, rows, cols, height, width) which becomes: OFFSET(Sheet1!$A$1,0,0,COUNTA(Sheet1!$A:$A)) (assuming your data is in a worksheet called "Sheet1"). To implement this, using our previous example of plotting column A against column B. 1. Create 2 named ranges called ColA and ColB (for example). For Column A, from the Insert menu choose Name then Define. In the names box type ColA and in the Refers to box type =OFFSET(Sheet1!$A$1,0,0,COUNTA(Sheet1!$A:$A)) Press Add For Column B, in the names box type ColB and in the Refers to box type =OFFSET(Sheet1!$B$1,0,0,COUNTA(Sheet1!$B:$B)) Press Add and close the dialogue box. 2. Insert a chart plotting Column A against Column B. 3. We now need to edit the chart so it automatically updates. Select the chart, right-click the plotted data series and select Source Data. Replace the current X Values with =Sheet1!ColA Replace the Y values with =Sheet1!ColB (In the in the formula bar this will look like: =SERIES(,Sheet1!ColA,Sheet1!ColB,1) 3. Click off the chart and start importing data into Excel. The chart will continually update no matter how many rows of data you collect. For details of getting live data from Windmill into Excel, see http://www.windmill.co.uk/excel/ For more on charting with Excel see http://www.windmill.co.uk/excel/excel-charting.html ________________________________________________________ * 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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