Windmill Software Ltd
Windows Engineering Software

November 2003

The Newsletter for PC-Based Data Acquisition and Control
Issue 64       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

* Windmill News: Windmill 6 Launched Today!
* When to Isolate Data Acquisition Equipment
* Excel Corner: Reducing the Size of Spreadsheets


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 
- Start logging when you press the space bar on the 
- 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 

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

Windmill still costs just 145 GB pounds (210 Euros or 
250 US dollars). To purchase the new package visit

Upgrading from Version 5 is no problem - all your 
existing Windmill settings are retained.  To upgrade 
contact [email protected]


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 -

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.


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

* Copyright Windmill Software Ltd
* Reprinting permitted with this notice included
* For more articles see

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
and an index of articles at

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]


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