Windmill Software Ltd
Data Acquisition Intelligence

August 2010

The Newsletter for PC-Based Data Acquisition and Control
Issue 145        August 2010
--------------------ISSN 1472-0221----------------------

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* Windmill Notes: Finding Data in Serial Messages
* Excel Corner: Charting Tips
* DAQ News Roundup

Windmill Notes: Finding Data in Serial Messages

When you collect data from instruments that communicate 
over RS232, RS485 or Modbus, you need to extract the 
readings from the rest of the message. You need to "parse" 
the message to extract just the data items in which you 
are interested.

Windmill has two divers to collect data from serial 
instruments. COMIML handles Modbus, RS485, RS422 and 
RS232 devices. More information is at

LabIML is less versatile but is free to Monitor 
subscribers. It handles RS232 devices.

Using Windmill you have three methods of locating your 
data item:
1. Search for specific characters in the message string.
2. Ignore characters until one of the ones you want appears.
3. Ignore a number of characters in the message string. 

At first glance methods one and two seem to do the same 
job, but there are differences.

1. When you search for characters the next action occurs 
   AFTER the search term. When you ignore characters the 
   next action occurs ON the specified character.  So if 
   you searched for a + sign you would not be able to 
   extract it, but if you ignored all characters until 
   the + sign you would. 

2. A search will look for the entire string specified 
  (eg "abc"), whilst ignoring characters will stop at any 
   of the characters specified (eg "a" or "b" or "c").

Excel Corner: Charting Tips

We gave some tips for choosing an appropriate Excel chart 
type in issues 30 and 60 of Monitor, archived at and

The US Energy Information Administration's "Guidelines 
for Graphs" gives pointers on annotating and organising 
charts like these.  For example.

Layout and Scale
1. Avoid clutter that does not add necessary information 
   for interpreting the graph (e.g., too many arrows, 
   bubble boxes, grid lines, extra tick marks and other 
   non-data features). 

2. When possible, order values from highest to lowest or 
   from lowest to highest if the data are not a 
   time series. 

3. Use the same scale whenever appropriate, so that the 
   related graphs can be compared using a common scale.

Dual axis graphs
1. Labelling is important when using a dual axis graph. 
   Different scales are permitted on a dual axis graph. 

2. Different chart types may be used for the variables, 
   such as bars for volumes and lines for prices. 

3. Use different colors for each variable and associate 
   the variable's color with the axis label to help users 
   determine which y-axis to use. 

4. Stacked bar graphs and cumulative line graphs are not 
   permitted in dual axis graphs.

Three-dimensional graphs
Avoid using three dimensional graphs when a two dimensional 
graph will present the same information. 

Further Reading:s

More Excel charting tips are at

If you have a question about using Excel for data 
acquisition, please get in touch. Fill in the form at 

DAQ News Roundup

Welcome to our roundup of the data acquisition and 
control news.  If you would like to receive more 
timely DAQ news updates then grab our RSS newsfeed 
at  Read for notes
on how to display the live news on your own web site.

Virus targets Siemens control systems
   Dubbed Stuxnet and spread by devices plugged into 
   USB computer ports, a new virus targets process control 
   systems made by Siemens and is programmed to steal data 
   from them. Microsoft has issued an emergency patch for 
   the Windows Shortcut hole and Siemens offers advice at
   Source: cnet news

Sensing Wind Speed with Kites 
   Kites have a long history in meteorological research, 
   including being used to carry aloft sensors that 
   measure wind speed. However, because these sensors 
   were exposed to direct sunlight they were prone to 
   temperature errors that affected their accuracy.  Now 
   researchers have developed a way to use a kite itself 
   to measure wind speed: a ground-based strain gauge 
   monitors the tension in the kite's tether line.  That 
   line tension is linearly related to wind speed. 
   Source: American Institute of Physics

Warning system monitors lube oil on ships
   University researchers have developed a computerised 
   early-warning system which keeps the 'lifeblood' of a ship 
   flowing: lube oil. Until now, while ships engine rooms 
   have become automated, with sensor systems being put in 
   place to monitor temperature, pressure, fluid level and 
   flow monitoring - lube oil has remained a void in the 
   engine management system.
   Source: University of Sunderland

Comb System Detects Gas Impurities to Aid Semiconductor Manufacturing 
   Purity of ingredients is a constant concern for the 
   semiconductor industry, because a mere trace of 
   contaminants can damage or ruin devices. In a step toward 
   solving a long-standing problem in semiconductor 
   manufacturing, scientists have used their version of a 
   "fine-toothed comb" to detect minute traces of contaminant 
   molecules in the arsine gas used to make a variety of 
   photonics devices.
   Souce: NIST

Handset Motion Sensor Market to Grow
   ARCchart are predicting that the market for 
   accelerometers, gyroscopes, magnetometers and pressure 
   sensors will exceed $1 billion by 2014 as they are 
   incorporated into phone handsets. Accelerometers are 
   expected to see the greatest device penetration, with 
   55% of phones containing them by 2014. Penetration in 
   smartphones will be substantially higher - 60% of 
   these devices are expected to have a gyroscope in 
   five years time. 
   Source: ARCchart

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

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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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