Windmill Data Acquisition Software Logo
22 August 2019

Windmill Software Ltd
Data Acquisition Intelligence
Call now: +44 (0)161 833 2782

Monitor - ISSN 1472-0221
The Newsletter for PC-Based Data Acquisition and Control
Issue 251, August 2019

Welcome to the 251st issue of Monitor. This month: lots of tips for data logging with Windmill software. For a full archive of back issues see

Follow @DataAcquisition on Twitter Data Acquisition News Feed (RSS)


* Tips for Data Logging with Windmill
* Your DAQ Questions Answered: Connecting a Balance
* Measurement and Control Exhibitions and Conferences
* Data Acquisition News Round-Up

Tips for Data Logging with Windmill

The Windmill Logging software is packaged with all our hardware. It is also available for free with a serial driver (RS232, RS485, Modbus and TCP/IP) to Monitor subscribers. Email [email protected] for your copy. It is easy to set up and use, but also has some advanced features you may find useful.

Logging Data Continuously to a Series of Files

Windmill comprises a suite of data acquisition programs. One of these, Logger, saves data to disk. For some applications, quality assurance for example, you will want to log data continuously. If you did this to just one file, it may become too large and unmanageable. The answer is to instruct Logger to periodically close the current file and create a new one. You can choose any time scale to do this: choosing a number of minutes, hours, days or weeks. Logger identifies each file by an incrementing, 3-digit, number.

How to do this?

  1. In Logger, select DataFile from the menu bar
  2. Type a name for the files that are to hold the data. This must include three question marks. When Logger creates the file, it replaces the question marks by a number. For example, the file name might be data???.wl (wl stands for a Windmill Logger file). The first set of readings is stored in data001.wl, the second in data002.wl, etc.
  3. Check the "Periodically open new log file" box.
  4. Press the Settings button.
  5. Choose the length of time you want a file to be open and saving data.

Restarting Logging to the same Files

You might want to stop logging for a while but then restart to the same sequence of files. This is no problem. Press the Pause button and Logger will wait until you press Resume and then continue logging to the currently open file. (Unless you have paused for longer than your file interval, when Logger will save the data in the next file in the sequence.)

Press the Stop button instead of Pause, and Logger will close the file rather than just suspending logging. On subsequently pressing Start, Logger will ask if you want to append the data to the most recently open file, or to start from file 001 and overwrite its data.

To be safe then, if you want to keep all data, choose Pause. However, if you want to open the file in other programs, before resuming logging, you must press Stop. Pause leaves the file open and it is therefore unavailable to any other software.

Logging Only when New Data arrives from Sensors and Devices

You can choose to log only new data values. This allows external events to control logging. For example, you could tell Logger to save data values only when you press a button on your instrument. It is also useful if your instrument sends data sporadically.

The data does not have to change to be logged. For example, imagine you are using our COMIML serial driver to gather data from an electronic balance. Every time you press a button on the balance, COMIML takes a reading. It might be that two consecutive readings happen to be identical. However, every time COMIML takes a reading it updates a "record number". Logger watches the record number and so knows when new data is available, even if it is the same value as the previous reading.

Logging only when new data arrives

More details are at

How do I Later View and Analyse the Data?

Logger will display each reading as it collects it, with values outside alarm thresholds shown in blue (warning alarm) or red (critical alarm). Older data will eventually scroll off the top of the window. During data collection you can also use the Windmill Chart program, to show data graphically.

After collection has finished you have a choice of ways to see the data. For example you can open the data in any software accepting ASCII values such as Excel, Notepad or Open Office. You can choose how the columns of data are separated - by tabs, commas or spaces (which is a good option for sending directly to the printer or plotter).

Your Data Acquisition Questions Answered: Connecting a Balance


Hi, I am looking for an interface that can read data from a balance that is connected to a PC with a RS-232 interface. Can your software do that?


Yes, Windmill software has been used with many different types of balance, including those from A and D, Adam Equipment, Denver, Mettler Toledo, Ohaus, Rice Lake and Sartorius. You can find example settings for these and other instruments at

Measurement and Control Exhibitions and Conferences

The quarterly update of data acquisition and control exhibitions around the world.

Electronics and Instrumentation

17-19 September 2019
Saint Petersburg Russia
Trade fair for technologies, equipment, services, certification and instrumentation.

Industrial Automation Show

17-21 September 2029
Brno Czech Republic
The digital factory including electronics, automation and measuring technology.

Sensors and Instrumentation Live

26-26 September 2029
Birmingham UK
The world of sensors, test, measurement and control.

International Engineering Fair

7-11 October 2029
Shanghai China
Industrial automation, electrical systems, robotics and IT solutions.

Testing and Control

22-24 October 2029
Moscow Russia
International exhibition of testing, measurement and control.

Advanced Engineering

30-31 October 2019
Birmingham UK
The UK's largest annual advanced manufacturing trade show spanning design, test, measurement, inspection, production and assembly.

China Electronics Fair

30 October - 1 November 2019
Shanghai China
A gateway to the world's fastest growing electronics markets. Includes electronic equipment, intelligent manufacturing and test and measurement instruments.

Sensors USA

20-21 November 2019
California USA
This event will bring together material suppliers, component providers, sensor manufacturers and end users. Focus is commercialisation of disruptive sensor technology, including applications in the Internet of Things.

Electrotest Japan

15-17 January 2020
Tokyo Japan
Asia's leading exhibition specialised in test, inspection, measurement and analysis for electronics manufacturing and research and development.


31 March - 2 April 2020
Kielce Polanc
Fair of Industrial Measuring Technology

Mach 2020

20-24 April 2020
Birmingham UK
Latest products, services and leading-edge developments across manufacturing sectors.

DAQ News Round-up

Welcome to our round-up of the data acquisition and control news. If you would like to receive more timely DAQ news updates then follow us on Twitter - @DataAcquisition - or grab our rss feed.

No batteries needed for underwater internet-of-things

New battery-free underwater communication system uses near-zero power to transmit sensor data. The system could be used to monitor sea temperatures to study climate change and track marine life over long periods.
Source: SCUBA News

Battery-free underwater sensor communication
A battery-free underwater piezoelectric sensor invented by MIT researchers transmits data by absorbing or reflecting sound waves back to a receiver, where a reflected wave decodes a 1 bit and an absorbed wave decodes a 0 bit - and simultaneously stores energy. Image courtesy of the researchers

Graphene sensors to measure air quality

Graphene-based sensors that can measure the quality of air using the 2D Material could soon enter mass production
Source: Manchester University

NIST Releases Draft Security Feature Recommendations for IoT Devices

The Core Baseline guide offers practical advice for using everyday items that link to computer networks.
Source: NIST

Sensing technology set to enhance tests for livestock disease

Sensing technology is being used to enhance the accuracy of detecting common infections in livestock which will help reduce the use of antibiotics in farming.
Source: Farming UK

Sensor provides next-generation ice detection

New sensor uses microwaves to determine real-time ice accumulation
Source: The University of British Columbia

* 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 other publication, providing the above notice
is included and a link back to our website is in place.

For previous issues by subject see

SUBSCRIBING OR CANCELLING SUBSCRIPTION Visit and add or remove your e-mail address.

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]

Subscribe to Monitor

Previous Issue Next Issue