Windmill Software Ltd
Data Acquisition Intelligence

Serial Communications Software
September 2001

The Newsletter for PC-Based Data Acquisition and Control
Issue 38      September 2001
--------------------ISSN 1472-0221----------------------

Welcome to Issue 38 of Monitor. We hope you enjoy it but 
should you wish to cancel your free subscription please 

* Windmill News:  New Version of Trouble-Shooting 
  Software for Serial Communications
* Data Acquisition News: Emissions Trading
* Excel Corner

Windmill News: New Version of Trouble-Shooting 
Software for Serial Communications

A new version of ComDebug, the serial communications 
software for RS232, RS422, RS485 and Modbus devices, is 
now available free to our readers.

The new version integrates more seamlessly into a 
Windmill system and corrects the mixing up of the odd 
and even parity. With ComDebug you can control the 
majority of serial instruments, including those from 
Bruel and Kjaer, Mettler Toledo, Microchip, Motorola, Molytek, 
Omron, Parallax, Sartorius, Siemens and Texas 

For more details, and to download your free copy, visit

Data Acquisition News: Emissions Trading

Last month the British Government launched the world's 
first greenhouse gas trading scheme. Briefly, companies 
can volunteer for the scheme by agreeing an emissions 
reduction in return for a financial incentive. This is 
good news for data acquisition companies like ourselves, 
who produce emission and energy monitoring software.

The government has promised 215m pounds, over 5 years 
from 2003, for the incentive payments. They plan to set 
the targets and incentives through a bidding process in 
January. Those failing to reach their emission reduction 
targets will have to pay back the incentive money with 
interest, and will face tougher targets in future years 
to make up the shortfall.

Although this scheme is heralded as the first for 
greenhouse gas trading, the United States already 
operates a similar system to control sulphur dioxide and 
nitrogen oxide. Other initiatives are being considered 
in France, Canada, Australia and Germany. It is likely 
that the UK scheme will ultimately be merged into a 
European Union trading plan, a pilot of which is due to 
begin in 2005.

More Information:
More details of the UK scheme.
Issue 6 of Monitor discussed emission monitoring.

Excel Corner: Calculating Average Values and Standard 
Deviation for Live Data

We were recently asked how to get running averages and 
standard deviations for live data. Here's the answer.

1. You need an Excel macro to acquire live data, where 
   each set of readings is placed in the next empty row. 
   For an example of such a macro see our web site

2. Edit the macro so that instead of the first set of 
   data being placed in the first row, it is placed in the 
   third row.
   In our example macro change:
   "NoOfRows = 1" to "NoOfRows = "3" and
   "While NoOfRows < NoOfSamples + 1" to 
   "While NoOfRows < NoOfSamples + 3" 

3. Each channel's data (temperature, strain or humidity 
   for instance) is stored in a column. Enter the Average 
   formula for the data in Row 1 and the Standard 
   Deviation formula in Row 2. If you were collecting 
   20 data readings for one channel, for example, you'd 
   have AVERAGE(A3:A23) and STDEV(A3:A23).

4. Start Windmill DDE Panel.

5. Run the Excel macro. You will be asked how many 
   samples (sets of data) you want to collect. Twenty in 
   our example. You will also be asked the interval between 
   samples. Excel will then read data from all your 
   channels. As each row of data is added, the average and 
   standard deviation for each channel is updated


Indicating Alarms when Average Levels are Exceeded

You can tell Excel to indicate whether the current 
averages are outside test limits. Simply use an IF 
statement. For example
Here A2 contains the average calculation and 30 is the 
test limit. If A2 is over 30 Excel shows "Alarm", 
otherwise it shows "OK".

This is fine if you are looking at the Excel screen. 
However, if you are collecting a large number of 
samples, or over a long time scale, you may prefer to 
have a permanent record of alarm conditions. Our 
Windmill Blackboard program lets you send your averages, 
standard deviations and any other calculated values back 
to the Windmill system, where they can be logged 
alongside the raw data.

For more details contact Windmill Software, 
[email protected]

* 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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