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Data acquisition and control

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751: Multifunction Data Acquisition USB Unit

751 Multi-function USB Data Acquisition with Windmill Software: 16 analogue inputs, 32 digital i/o, 8 counters

For 16 differential analogue inputs, 16 digital inputs/outputs and 8 counters. You can connect eight 751s to one PC. With the addition of suitable Microlink 59x conditioning units, you can also monitor thermocouples, strain gauges, pressure transducers and current. Includes Windmill data acquisition software for logging, charting, output control and direct data transfer to Excel.

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Microlink 840: Versatile Data Logging over Ethernet and Internet

Microlink 840: Versatile data logging

The culmination of 30-years of experience designing data acquisition and control systems has resulted in this extremely versatile, compact unit which lets you monitor analogue transducers, digital sensors, utility meters, machines and digital status. It can also raise alarms and control digital outputs.

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750: Low Cost Measurement & Control

750 USB Data Acquistion with Windmill Software: analogue input, digital i/o, counters, free technical support

16 analogue inputs, 16 digital inputs/outputs, 8 counters and Windmill logging and control software. Connect up to 8 units to a PC. Data saved in text files, or passed directly to Excel.

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pH Data Logging over Ethernet and Internet

851-pH: pH Data Logger with Digital I/O and Counting

This package logs data from 12 pH probes. It comprises Windmill software, a pH data logger and pH signal conditioning. The pH probes connect to BNC sockets. You can read data over an Ethernet network.

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Thermocouple Monitoring

Thermocouple measurement over USB, Windmill 7 software & free technical support

Monitor 16 thermocouples and voltages, digital I/O and counting. Connect 8 units to 1 PC and monitor 128 thermocouples.

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Strain Gauge Monitoring

Strain Measurement:  USB Data Acquisition Unit, Strain Gauge Connection Box, Windmill Software, free technical support

Monitor 16 strain gauges, balanced bridges like pressure transducers or voltage signals. Connect 8 units to 1 PC and monitor 128 strain gauges. Readings in microstrain. Zero reference level can be set in Windmill software. Plus digital input & output and counting.

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Microlink 851: Data Acquisition & Control over Ethernet & Internet

DAQ Catalogue | Data Acquisition Hardware: Ethernet and Internet |  Microlink 851: Data Acquisition & Control over Ethernet & Internet

851: 16 Analogue inputs, 32 digital i/o, 8 counters, Windmill software

851: 16 Analogue inputs, 32 digital i/o, 8 counters, Windmill software

Price: 755.00 (Excluding VAT at 20%)


Provides 16 analogue inputs, 32 digital inputs/outputs and 8 counters. Monitor voltage, strain, temperature, pressure, pH and current (extra modules might be needed). Comes complete with Windows software, free technical support for life and a money-back guarantee if not satisfied. You can use the 851 for real-time data acquisition on your PC or stand-alone data logging.

Features | Digital Inputs and Outputs | Counting | Measuring Temperature | Measuring Strain and Pressure | Measuring Current | Measuring pH | Signal Connections | Software | Ethernet | Specifications | Download Leaflet


  • Analogue voltage measurement; can also measure strain, temperature, pressure, pH and current with extra units
  • Rebalance all strain gauges in one go
  • Read and switch digital inputs and outputs
  • Event counting
  • Frequency measurement
  • Includes the powerful yet easy-to-use Windmill 7 Software for Windows: no programming required
  • Choice of four analogue input ranges, selected with Windmill software individually for each channel
  • Alternatively, choose automatic ranging and let the software match the input signal as closely as possible
  • Integrating analogue-to-digital converter reduces electrical noise
  • Use Windmill software to select the resolution of the A-D converter (from 12- to 18-bits): choose high throughput or high resolution
  • Automatic recalibration
  • All data displayed and saved in the engineering units of your choice: volts, millivolts, Celcius, fahrenheit, microstrain, hertz, kilohertz, etc
  • Free technical support for life
  • Money-back guarantee if not completely satisfied

Digital Inputs and Outputs

The 851 provides 32 digital I/O lines, arranged in four groups of 8. Use Windmill software to choose whether each group is an input or an output. You can read or set the state of each line individually, or switch several lines at the same time.


The 851 has eight counters which you can use for counting events or measuring frequency.

When counting events, you can use the counters in two modes: accumulating count and resetting count. In accumulating count the counter keeps going until you reset it from software. In resetting count the counter shows the number of pulses since the last reading.

When measuring frequency you can count over 1 or 10 second intervals.

You can scale counts using Windmill software. For example if the pulses came from a flow meter which produced one pulse for every 50 millilitres, a scale factor of 0.05 would give a reading in litres.

The counters are found on 8 of the digital input and output lines. You can use any of these you don't need for counting as normal digital inputs: the counts are always maintained even if you don't plan to use them.

Measuring Temperature

thermocouple measurement box

Depending on your transducers, you might need extra hardware units to make your connections. For example, for thermocouples you will need a 593 box which provides cold junction measurement.
(When monitoring thermocouples it is essential that the system knows the temperature of one of the thermocouple junctions. Housing this junction in the 593 isothermal box keeps the temperature constant, and a cold junction sensor in the box tells the system the temperature. You connect the thermocouple wires to screw terminals in the 593 isothermal box, and connect the terminals to the 851 unit with a ribbon cable. The 593 also detects broken thermocouple leads for you.)

Measuring Strain and Pressure

For strain add a 594 unit. This lets you monitor strain gauge bridges and balanced bridges such as pressure transducers. You can configure individual channels to accept any of these inputs:

  • voltage
  • quarter bridge: single strain gauge
  • half bridge: tensile + compressive strain gauge
  • half bridge: normal + transverse strain gauge
  • full bridge: 2 tensile + 2 compressive gauges
  • full bridge: 2 normal + 2 transverse gauges
  • full bridge: tensile normal + compressive normal + tensile transverse + compressive transverse gauge

Measuring Current

For current add a 590- 8A to your shopping cart. This has many extra facilities, including:

  • contact closure inputs
  • higher voltage inputs than normal
  • input protection from high voltages
  • external current source switching
  • output protection

Measuring pH

For pH add a pH-box to your shopping cart. This lets you monitor 12 pH electrodes

Signal Connections

The slim 851 offers pin connections for your signals. However, if you prefer to use screw-terminals these are provided by adding one of the 59x Series of units. For analogue voltages, digital I/O and counters, choose the 590 unit. This allows many extra facilities, such as:

  • contact closure inputs
  • higher voltage inputs than normal
  • input protection from high voltages
  • external current source switching
  • output protection

For current, thermocouples, strain gauges and presssure transducers - choose the Microlink 590- 8A, 593, and 594 respectively.


The 851 is supplied with Windmill data acquisition and control software. This modular suite of software regularly collects data from the 851, charts it, shows alarms, lets you control outputs and can transfer data in real-time to other applications like Excel. You can also add process mimic generators, sequence control and other options. Should you wish to program the 851 yourself, you can use the IML Tools to do so.

Windmill chart recorder and data  logger

The Windmill Chart and Logger programs


Ethernet offers a good, low-cost, option for distributed measurement and control. You may add data acquisition devices to existing Ethernet systems: saving installation costs and time. Speed-wise it is faster than serial communications. As with all distributed systems, you can place data acquisition hardware close to sensors reducing cabling costs and errors produced by noise. Ethernet uses the TCP/IP protocol so you can access data over the Internet.


 Dimensions (mm)           180 x 120 x 40
Maximum logging speed 10 scans a second
Memory 65000 scans
Operating system Windows 10, 8, 7 64-bit, 7 32-bit
Vista, XP, 2000 or 98
Maximum # inputs 16 differential
Maximum safe input voltage:
Power supply on ±48 V
Power supply off ±33 V
Transient ±300 V
Ranges (V) ±0.01, ±0.1, ±1, ±10
Common mode range ±13 V
Relative accuracy of ranges:
gain = 1000 ±0.1%
gain = 1, 10, 100 ±0.05%
Analogue to Digital Converter:
Maximum linearity error ±0.02%
Resolution Integration Time Samples/Second
12 bits 2.5 msec 80
13 bits 5 msec 64
14 bits 10 msec 48
15 bits 20 msec 32
16 bits 40 msec 16
18 bits 160 msec 6
Maximum # inputs 32
Maximum # outputs 32
(selected through Windmill in ports of 8 lines)
Power-up state all inputs
Compatibility TTL and 5 V CMOS, can be made
contact closure compatible
Range 0 to 5 V
Output capability 15 LSTLL loads
Maximum I/O speed 160 channels per second
Maximum # counters 8
Resolution 23 bits
Maximum count (events) 1000000
Maximum frequency 5 kHz
Minimum pulse width 500 µseconds
Frequency gate times 1 or 10 seconds
Compatibility TTL, 5 V CMOS, can be made
contact closure compatible
Input voltage range 0 to 5 V

More Information

If you need any more details please contact Windmill Software or download the 851 Ethernet leaflet.

DAQ Catalogue | Data Acquisition Hardware: Ethernet and Internet |  Microlink 851: Data Acquisition & Control over Ethernet & Internet