Windmill Software Ltd
Data Acquisition Intelligence

September 2009

The Newsletter for PC-Based Data Acquisition and Control
Issue 134     September 2009
--------------------ISSN 1472-0221----------------------

Welcome to Monitor, the data acquisition newsletter.  I 
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* Windmill News: Data Acquisition and Control Glossary
* Excel Corner: Quick Formula Help 
* DAQ News Roundup

Data Acquisition and Control Glossary

We've updated our glossary of terms relating to data 
acquisition and control.  Thanks for pointing out words 
we had missed. For the full glossary go to

  A false picture of a high frequency waveform that has 
  been sampled at too low a rate. 

Acquisition Time
  In analogue-to-digital conversion, the time taken for 
  the sample and hold circuit to settle to the input 
  voltage.  Also known as Sample and Hold 
  Acquisition Time. (Sample and hold circuits are not 
  used with integrating converters.)

  A signal that ranges between a negative and a positive 
  value, -10 V to +10 V for example.

  Transfers data from the data acquisition device to the 
  computer. Examples include Universal Serial Bus, 
  Modbus and General Purpose Interface Bus.  Network 
  communications like Ethernet are not generally 
  regarded as buses.

  A temperature scale where the freezing point of water 
  is 0 degrees and the boiling point 100 degrees. 
  Symbol is C.

Conversion Time
  The time taken to convert an analogue signal to a 
  digital signal. The sample and hold circuit of an 
  analogue-to-digital converter freezes an otherwise 
  varying analogue voltage at the moment the sample is 
  required. This voltage is held constant whilst the 
  A-D converter digitises it. 

External Trigger
  A trigger is something that causes data acquisition 
  to start.  An external trigger lets you synchronise 
  data acquisition with something happening in the real 
  world.  For example when you switch on a machine or 
  when a signal crosses a threshold. 

  A 2-wire serial bus developed by Philips.

Integrating A-D Converter
  An integrating A-D converter averages the input signal 
  over a length of time. This is useful when the signal 
  to be measured fluctuates slowly. By averaging the 
  signal the converter helps reduce unwanted signal 
  contamination (noise).

  A temperature scale where the freezing point of water 
  is 32 degrees and the boiling point 212 degrees. 
  Superceded for scientific purposes by Celsius. 
  Symbol is F.

  A temperature scale which is one of the seven base 
  units in the International System of Units (SI). 
  In theory, the zero point on the Kelvin scale is the 
  lowest possible temperature where there is no heat 
  energy: -273.15 oC.  The freezing point of water is 
  273.15 Kelvins and the boiling point is 373.15 K.  
  Symbol is K. 

Least Significant Bit, LSB
  In a binary number, the 1 or 0 furthest to the right.

Most Significant Bit, MSB
  In a binary number, the 1 or 0 furthest to the left.

Negative Edge Trigger
  Data acquisition starts when an input signal changes 
  from a high to a low state.

Positive Edge Trigger
  Data acquisition starts when an input signal changes 
  from a low to a high state.

More definitions are at

Excel Corner: Quick Help on Formulae

When you know the name of a formula but can't remember 
the arguments it takes.
1. Enter the name of the formula in a cell.
2. Press Ctrl A. The Function Wizard appears letting you 
   enter values and creating the formula for you.

Alternatively, if you just want to view the arguments 
in the formula.
1. Enter the name of the formula in a cell
2. Press Ctrl+Shift+A.  You will see all the arguments 
   for that function-

For more tips on using Excel see

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.

Lower-Cost Solar Cells to Be Printed Like Newspaper
   Solar cells could soon be produced more cheaply using 
   nanoparticle "inks" that allow them to be printed like 
   newspaper or painted onto the sides of buildings or 
   rooftops to absorb electricity-producing sunlight. 
   Researchers are hoping to cut costs to one-tenth of 
   their current price by replacing the standard 
   manufacturing process for solar cells - gas-phase 
   deposition in a vacuum chamber, which requires high 
   temperatures and is relatively expensive.

Prototype Detects and Measures Elusive Hazards
   NIST has demonstrated a relatively simple, 
   inexpensive method for detecting and measuring 
   elusive hazards such as concealed explosives and 
   toxins, invisible spoilage in food or pesticides 
   distributed in soil by wind and rain.  Preliminary 
   results indicate the method is sensitive enough to 
   measure amounts of target materials that constitute 
   as little as 0.0000002 percent of a sample.

Automotive Bus Driven Forward
   An industry consortium as been formed to drive further 
   development and deployment of the Distributed Systems 
   Interface (DSI) standard. DSI is the automotive 
   industry's most widely adopted bus standard used to 
   connect remotely placed sensors to the main airbag 
   electronic control unit (ECU) in automobiles.

Electronic Nose Sniffs out Toxins
   Imagine a polka-dotted, postage stamp sized, sensor 
   that can sniff out poisonous gases and toxins and 
   show the results simply by changing colors. This is 
   what is being developed by the National Institute of 
   Environmental Health Sciences

Naval Sensor Market to Grow
   New analysis from Frost and Sullivan into the 
   European naval sensors market, finds that the market 
   earned revenues of over $28 million in 2008 and 
   estimates this to reach $91 million in 2017. The market 
   will likely grow by a further 35 per cent due to the 
   rising importance for advanced technology and upgrades 
   across European navies.

* 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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