Windmill Software Ltd
Windows Engineering Software

April 2003

The Newsletter for PC-Based Data Acquisition and Control
Issue 57 April 2003
--------------------ISSN 1472-0221----------------------

Welcome to April edition of Monitor, the newsletter for 
data acquisition and control. We only send Monitor to 
people who have subscribed - should you wish to cancel 
your free subscription please do so at

* Windmill News: Accurately measure resistance via USB
* Excel Corner
* Data Acquisition Exhibitions and Conferences

Windmill News: Accurately Measure Resistance via USB

Now available from our on-line catalogue: the Microlink 
752 Resistance unit. Not only does it measure 
resistance, it also allows you to control voltage and 
current outputs, count up to 65535 and monitor analogue 
and digital voltage signals. 

The compact unit, measuring 180 x 120 x 40 mm, plugs 
into the PC's USB socket. Quick and easy to install, it 
is supplied with our Windmill software suite of Windows 
logging, charting, display and control applications. 
Also included in the package is free technical support 
for life.

The Microlink 752 has been designed for accurate 
resistance measurement and you can use it with 4-wire 
cabling. This arrangement negates the resistance in 
the leads which otherwise would lead to errors in the 
readings. You could also use 2-, 3- or 
4-wire compensated wiring.

Measuring the change in resistance is used, for example, 
to acquire temperature, displacement or light level 

The Microlink 752 resistance package costs 795 GB pounds 
(around 1155 Euros or 1255 US dollars). For more 
information see
or contact [email protected]

For more on measuring resistance see Issue 1 of Monitor

Excel Corner

After last month's discussion on logging data only when 
readings changed, we were asked how to use Excel's 
SetLinkOnData method to do so from all instrument 

To do this
1. In Windmill DDE Panel select the Copy to Clipboard 
button and copy data from All Channels.
2. From Excel's Edit menu choose Paste Special and 
"Paste as Links" into the first row of a worksheet 
called "Sheet1".
3. Create the macro given below and run MonitorDDE.

The MonitorDDE routine monitors a worksheet which is 
being updated via DDE. When values change, it calls the 
LogData procedure which progressively writes the 
readings into new rows in the worksheet.

Dim NoOfRows As Integer

Sub MonitorDDE()
NoOfRows = 1
' Monitors the DDE links for updates
' When data is updated runs the subroutine LogData
ActiveWorkbook.SetLinkOnData "WINDMILL|Data!AllChannels", "LogData"
End Sub

Sub LogData()

NoOfRows = NoOfRows + 1

ddechan = DDEInitiate("WINDMILL", "Data")

' Requests readings from all the channels shown in the 
' Windmill DDE Panel program and stores them in an array 
' called mydata.
mydata = DDERequest(ddechan, "AllChannels")

' Ignores any warnings generated
On Error Resume Next

' Finds the lower & upper boundaries of array, to 
' determine the number of columns needed to store 
' the data.
Lower = LBound(mydata, 1)
Upper = UBound(mydata, 1)

' Inserts data from the array into a row of cells in a 
' worksheet called Sheet1.
For Column = Lower To Upper
Sheets("Sheet1").Cells(NoOfRows, Column).Value = mydata(Column)
Next Column

DDETerminate (ddechan)

End Sub


For more tips on using Excel with Windmill see
For more on the SetLinkOnData method see Monitor 
issue 56
or the Microsoft site

Data Acquisition Exhibitions and Conferences

Continuing our bi-monthly listing of exhibitions and 
conferences related to data acquisition and control.

ISA Ireland
29 April
Cork. Ireland
The Instrumentation, Systems, and Automation Society 
exhibition and seminar

Manufacturing Excellence
29 April - 1 May
Yarm Teedside UK
Presentations and papers on instrumentation, energy 
efficiency, pharmaceuticals, safety, etc.

Sensor 2003
13-15 May
Nuremberg Exhibition Centre Germany
Features sensors plus measuring and control technology.

27-30 May
Budapest Fair Centre Hungary
International trade fair featuring electronic measuring 
instruments, control engineering, automation, data 
collection, energy management, etc.


* 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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