Windmill Software Ltd
Data Acquisition Intelligence

September 2007

The Newsletter for PC-Based Data Acquisition and Control
Issue 110     September 2007
--------------------ISSN 1472-0221----------------------

Thanks for continuing to subscribe to Monitor.  This 
month guide to the different types of wireless networks 
you could use for data acquisition.

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* Windmill News: People counting help
* Logging data wirelessly
* Excel Corner: Adding several y axes to a chart 
* DAQ News Roundup

Windmill News: People Counting Help

You can now download the latest Help file for our people 
counting software.  Called VT Setup, the software 
improves the accuracy of counting people into and out of 
buildings.  It lets you tailor the system to suit each 
individual doorway and can handle hundreds of entrances.  
To download the new Help file go to

You need to unzip the files before you can use them. In 
Windows double-click the file and from the 
File menu choose Extract All.

For more on counting people see

Logging data wirelessly

Monitoring instruments and sensors wirelessly is 
becoming more and more common.  A wireless network 
saves cabling costs and installation time.  It is 
useful in electrically noisy or hostile environments. 
It lets you move your measuring device from place to 
place and remotely monitor conditions.  You can log 
data from your existing devices wirelessly by adding 
appropriate adaptors or routers.

There are several different methods of wireless 
communication.  The standards for many of these 
methods are still being developed.

  Bluetooth was designed as replacement for short-range 
  cables. It allows up to seven devices to be monitored 
  over short distances, typically about 10 meters. It is 
  called a wireless Personal Area Network (PAN) and 
  conforms to the IEEE 802.15 standard.  It is suitable 
  when devices are close to the computer and high 
  bandwidth is not required.  You can use Bluetooth to 
  log data from RS232 instruments by plugging a 
  Bluetooth radio adaptor into your PC's COM port and 
  one into your instrument. You can then use software 
  like Windmill's COMIML to collect data 
  Bluetooth is named after a Danish king who unified 
  Denmark and Norway.
  Further reading:

Wibree (Ultra Low Power (ULP) Bluetooth)
  Wibree is a new interoperable radio technology for 
  small devices like sports sensors.  It was designed 
  by Nokia for applications where ultra low power 
  consumption, small size and low cost were the critical 
  requirements.  In June this year it was decided that 
  Wibree would be included in the Bluetooth 
  specifications and renamed Ultra Low Power (ULP) 
  Bluetooth.  Further reading:

  Similar to a traditional Ethernet model, WiFi comprises 
  a local area network (LAN). It uses the same radio 
  frequency as Bluetooth, but with higher power consumption.  
  WiFi is preferable to Bluetooth for operating medium-to-
  large networks because it allows for a faster connection 
  speed, greater range, more devices to be monitored and 
  higher security levels. For more on WiFi and data 
  acquisition see Issue 82 of Monitor,

  ZigBee was designed specifically for remote monitoring 
  and control.  It comprises a personal area network based 
  on the IEEE 8-2.15.4 standard. ZigBee can support 
  thousands of nodes in a star or mesh network. In a star 
  network all devices communicate with the controlling node, 
  as is used by WiFi and Bluetooth. In a mesh network, 
  messages can be passed from node to node such that if any 
  of the nodes fail, the message can still reach the 
  destination.  Once associated with a network, a ZigBee 
  node can wake up and communicate with other ZigBee 
  devices then return to sleep. This and its low power 
  means that a device's battery can last a very long time.
  Further reading:

  Passed earlier this month, the HART 7 specification 
  includes the wireless protocol dubbed WirelessHART. 
  This sets out to create a wireless version of the 
  Wired HART protocol in order to ensure backward 
  compatibility with wired devices. HART Communication 
  is used to communicate between intelligent field 
  instruments and host systems.
  Further reading:

  WiMax, the Worldwide Interoperability for Microwave 
  Access, aims to provide wireless data over long 
  distances in a variety of ways. It is based on the 
  IEEE 802.16 standard, which is also called WirelessMAN. 
  Typically it has a range with a radius of 3 to 10 km. 
  The WiMAX Forum expects the technology to allow city-
  wide wireless broadband access. In the data acquisition 
  field, WiMax is envisaged as most useful for monitoring 
  offshore facilities. 
  Further reading:

  GSM (2G) networks are used for voice calls from mobile 
  (cell) phones. They are limited when it comes to sending 
  or receiving data as it can take up to 30 seconds to 
  make a connection to the network. GPRS is a method of 
  enhancing GSM. GPRS (General Packet Radio Service) 
  devices can transfer data immediately and at higher 
  speeds. GPRS uses the existing GSM network to transmit 
  and receive TCP/IP based data to and from GPRS mobile 
  devices. GPRS devices are always on, as opposed to 
  dial-up modems.  You can connect Ethernet devices to 
  a GPRS network by adding a suitable GPRS router.

More Wireless Resources:

IEEE Wireless Standards Zone
The IEEE is developing open, consensus standards for 
wireless networks.

The ISA-SP100 group formed in 2004 with the charter to 
establish standards and recommended practices for 
implementing wireless systems in the automation and 
control environment, with a focus on the field level.

ISA: Users fear wireless networks for control

Excel Corner: Adding several y axes to a chart

We were asked this month how to plot 3 variables on an 
Excel chart, each with a different y axis.  Excel doesn't 
offer an option to do this, but there are work-arounds 
to achieve it.

On way relies on using a dummy chart series to add a 
third axis.  This was pioneered by Jon Peltier.  He 
describes the method at

The second method is to display traces separately, 
like the Windmill Chart program does

Windmill Chart Recorder

This is also known as a panel chart, a trellis chart, 
a stacked line chart or a multi-plot chart. Details of 
how to achieve this in Excel are given at  
Jon Peltier's site at

For more on data acquisition and control 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 news on your own web site, 
read it via e-mail, mobile phone or a newsfeed viewer.

Ear-sensor helps athletes
   A new body sensor, the size of a hearing aid, 
   monitors the performance of an athlete while training. 
   The sensor fits behind the ear and gathers data about 
   posture, stride length, acceleration and response to 
   shock waves travelling through the body.  A computer 
   inside the earpiece and transmits data to a laptop 
   for real-time monitoring of athletic performance.
   Source: Imperial College

NIST measures challenges for wireless in factories
   Heavy industrial plants are challenging 
   environments for wireless systems.  They can be 
   highly reflective, scattering radio waves 
   erratically, and interfering with or blocking 
   wireless transmissions.  NIST have identified a 
   number of steps to take minimise radio interference 
   on the factory floor.
   Source: National Institute of Standards and Technology

Smart homes could track your electrical noise
   Your computer could one day track your movements 
   around the house by monitoring the electrical noise 
   made by household appliances as you switch them on 
   and off. Such a system could be cheaper and simpler 
   to operate than the suite of sensors that researchers 
   currently envisage for "smart homes".
   Source: New Scientist

Beyond Batteries: Storing Power in a Sheet of Paper
   Researchers at Rensselaer Polytechnic Institute, 
   New York, have developed a new energy storage 
   device that easily could be mistaken for a simple 
   sheet of black paper. The battery is lightweight, 
   ultra thin, completely flexible, and geared toward 
   meeting the trickiest design and energy requirements 
   of tomorrow's devices.
   Source: Rensselaer Polytechnic Institute

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* Reprinting permitted with this notice included
* For more articles see

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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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