-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 64 www.windmill.co.uk November 2003 --------------------ISSN 1472-0221---------------------- Welcome to Issue 64 of Monitor. Today we are pleased to use Monitor to launch a major new version of Windmill: Windmill 6. We hope you find the newsletter useful, but should you wish to cancel your subscription please do so at http://www.windmill.co.uk/newsletter.html CONTENTS ======== * Windmill News: Windmill 6 Launched Today! * When to Isolate Data Acquisition Equipment * Excel Corner: Reducing the Size of Spreadsheets ________________________________________________________ ________________________________________________________ WINDMILL NEWS: WINDMILL 6 LAUNCHED TODAY! ________________________________________________________ We are delighted to announce an improved version of Windmill, the data acquisition software suite. Windmill collects data from a vast range of sensors and equipment, including thermocouples, pressure transducers, flow meters, GPS receivers, laboratory instruments, USB and modbus devices. It comprises series of programs, all performing a specific task such as data logging. With the new Windmill, you now have four choices of how to trigger data logging. - Start logging when your equipment sends new data - Start logging when readings cross one of your alarm thresholds - Start logging when you press the space bar on the keyboard - Start logging when you press the software Start button The first option lets your equipment determine when Windmill takes readings. It is useful, for example, if you are using a balance and don't want to record the weight of the same item twice. Windmill monitors the balance, and only saves new readings. Even if two items weigh the same, Windmill knows that a change has occurred and logs the second reading. With Windmill you can set warning and critical alarms on each channel of data. If you wish you can now only log data when an alarm level is crossed. You can also set the duration of logging. Say a temperature reading rose above a set point for 5 minutes. Windmill would log data throughout this time. When the temperature returned to normal, Windmill would continue logging for your chosen duration. It would then stop until another alarm occurred. At regular intervals Windmill can automatically close the data file and open a new one. Rather than having all data saved in one file, this results in a new file for each hour's, each day's or each week's data. To save disk space you can opt to overwrite older files. You can choose to keep one day's, one month's or one year's data, or to keep all files indefinitely. Other improved programs include the COMIML serial driver. The new version makes it even easier to interface to a PC, almost any instrument communicating through ASCII messages over RS232, RS485, RS422 or Modbus. Windmill 6 runs under all flavours of Windows. All programs are ready-to-run and no programming is required - saving you time. Being modular though, flexibility isn't compromised. For more details of the new Windmill see http://www.windmill.co.uk/windmill.html Windmill still costs just 145 GB pounds (210 Euros or 250 US dollars). To purchase the new package visit https://www.windmillsoft.com/daqshop/software.html Upgrading from Version 5 is no problem - all your existing Windmill settings are retained. To upgrade contact [email protected] ________________________________________________________ ________________________________________________________ WHEN TO ISOLATE DATA ACQUISITION EQUIPMENT ________________________________________________________ Two circuits are isolated when there is no direct electrical connection between them. In a computerised measurement and control system, a high transient voltage at one input may damage not only the input circuit, but the rest of the data acquisition hardware and, by propagating through the signal conditioning and analogue-to-digital circuits, eventually damage the computer system as well. You can prevent this type of damage by isolating the input from the earth of the data acquisition and computer hardware. A transient at one input can also propagate across to other input circuits and then cause damage to other equipment connected to those inputs. This is prevented by providing isolation between inputs. Another case where you may need isolation is when you have very large ground loops. These may occur when the computer and DAQ equipment are widely separated. For more on ground loops see Issue 11 of Monitor - http://www.windmill.co.uk/differential.html Isolation is a special case of input protection. Inputs may be protected using components to limit the voltage at an input circuit. Electrical equipment that may be subject to switching transients, component failure, mis-wiring and so on should only be connected to isolated inputs. So a system used to test electrical equipment following manufacture would be a prime candidate for isolation. ________________________________________________________ ________________________________________________________ EXCEL CORNER: REDUCING THE SIZE OF SPREADSHEETS ________________________________________________________ When you reduce the number of columns or rows in a spreadsheet, you might not reduce its actual size in Kilobytes. To check whether your spreadsheet is overblown in this way, press the Ctrl and End keys on the keyboard. The cursor will jump to the last cell in the spreadsheet. If you have empty rows or columns select them and then choose Delete on Excel's Edit menu. The size of your file is now reduced. For more tips on Excel see http://www.windmill.co.uk/excel/ ________________________________________________________ * 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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