-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 75 www.windmill.co.uk October 2004 --------------------ISSN 1472-0221---------------------- Welcome to the 75th issue of Monitor. We hope you enjoy it, but should you wish to cancel your subscription you can do so at https://www.windmill.co.uk/newsletter.html CONTENTS ======== * Windmill News: Windmill Helps Locate Oil Contamination * Windmill Notes: Creating a User Interface with Windmill Graphics * Excel Corner: Showing Only Recent Data in a Chart ________________________________________________________ ________________________________________________________ Windmill News: Windmill Helps Locate Oil Contamination ________________________________________________________ When underground water is contaminated by oil, environmental agencies need to find the source and extent of the pollution. Traditionally this has been difficult to establish, but researchers at the University of Waterloo (Canada) are working on an answer. The scientists inject a solution of bromide and other tracer chemicals into the water. When these tracers hit the contamination, some are delayed more than others. Downstream, the team continuously pump up the water and monitor the tracer chemicals. The differences in breakthrough times of each tracer lets them estimate the total mass and distribution of the subsurface oil pools. To accurately measure the breakthrough of bromide they use Windmill Software and an Orion 290 A+ meter equipped with a bromide selective electrode. Dr Niels Hartog, one of the scientists involved in the project, commented... "With Windmill reading the serial output of the meter, I was easily able to continuously log bromide concentrations in the extraction wells." Windmill stores the data in a text file which can later be imported into almost any Windows analysis software, such as Excel. The handheld Orion meter, for performing pH and concentration measurements, is just one of the many devices which can be handled by the Windmill data acquisition software. To use Windmill for this type of application you need its serial driver. Details of the latest version of this, COMIML, are at https://www.windmill.co.uk/https://www.windmillsoft.com/daqshop/rs232-modbus.html. Alternatively, as a subscriber to this newsletter you can download an older version (LabIML) for free. To quickly configure the software for use with the Orion meter go to https://www.windmill.co.uk/serial_driver.html and download the set-up files. For more on Windmill software see https://www.windmill.co.uk/windmill.html ________________________________________________________ ________________________________________________________ Windmill Notes: Creating a User Interface with Windmill Graphics ________________________________________________________ You can create your own display and control windows with the Windmill Graphics program. Graphics customises the Windmill software suite, making a versatile system that is unique to your application. The window continuously reflects the state of the system in the real world. Once you've created a window you can protect it from further editing. You can make the display a simple front end, or show enough detail to keep the even the most data hungry happy. Virtual instruments, process mimics, annunciator panels, wiring diagrams... it's entirely up to you. To use Windmill Graphics you just: 1. Create a background in any painting package supporting bitmaps, Windows Paint for example. 2. Open the bitmap in Windmill Graphics and double-click the mouse where you want live text or graphics to appear. 3. Choose the type of live item and set its options. 4. Switch to protected run mode and see the window come to life, continuously updating with real-world data. Eight types of live item are available: - Analogue meters - Moving bars - Changing icons (eg open and closed valves) - Data readings with colour-coded alarms - Time and date labels - Analogue control buttons - Digital control buttons - Program control buttons Tips on Creating a Background Image =================================== 1. Start by using your painting package to set the size of your background. (Graphics always displays the background the same size as it was created.) Make sure you do not create an image that exceed the resolution of your screen, as Graphics cannot scroll images. Remember that Graphics will need additional room for a title bar. 2. You may find it useful to write down the co-ordinates of where you later intend to add dynamic items to the image. 3. In areas where you intend to add dynamically changing icons, draw the icon in the off state - for example a closed valve. You can then copy the valve, edit it to be an open valve and save it in its own file. This ensures that both the on and off versions of the icon are the correct size and colour. When you have created a background you are ready to use Graphics, and drop the dynamic items into their places. Further Reading =============== Tutorial on designing the user interface: process mimics, HMIs, etc... https://www.windmill.co.uk/interface.html More on Windmill Graphics https://www.windmill.co.uk/graphics.html ________________________________________________________ ________________________________________________________ Excel Corner: Showing Only Recent Data in a Chart ________________________________________________________ One of our readers asked if it were possible to create a chart that only showed recent data and automatically refreshed itself as new data arrives. We discussed how to create an automatically refreshing chart in issue 62 of Monitor, which is available at https://www.windmill.co.uk/monitor62.html You can adapt this method to only show the most recent data, the last hour's or week's for example. To do this: 1. In the first cell of an empty column of the spreadsheet, enter the number of rows of data you want to chart. For example, if you are logging data every minute and want to show the last hour's readings: enter 60. 2. When defining the range "ColB", enter =OFFSET(Sheet1!$B$1,COUNTA(Sheet1!$B:$B)- Sheet1!$G$1,0,Sheet1!$G$1) Where, Sheet1 is the name of your worksheet $G$1 is the cell containing the number of rows of data to be charted. Further Reading =============== For more on using Excel with Windmill see https://www.windmill.co.uk/excel/ For more on charting with Excel see https://www.windmill.co.uk/excel/excel-charting.html ________________________________________________________ ________________________________________________________ * 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)161 834 6688 Facsimile: +44 (0)161 833 2190 E-mail: monitor@windmillsoft.com https://www.windmill.co.uk/ https://www.windmillsoft.com/
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