µBOX: Sensor-USB Interface

Compact Plug-And-Play USB-DAQ and Signal Conditioning System for Sensor Signals

Figure1: The µBOX

The µBOX replaces:

- Power supplies for sensors and the corresponding cable connections
- Electronics for signal conditioning.
- The A/D Converter itself
- The signal cables from the A/D Converter to the computer (often noise suceptible flat ribbon cables)
- If plug-in cards are used, the effort to integrate and setup the card in the computer

High Resolution

With resolutions up to 20 Bit (P/P) and acquisition rates up to 25 kHz, the µBOX is designed to meet the highest demands.

If one considers that most standard digital oscilloscopes have a resolution of 8 bit (i.e. 1 to 256) higher quality ones 12 Bit (1 to 4096) and the most expensive ones 16 bit (1 to 65.536), then it is clear that the µBOX is far superior here.

The 20 Bit Resolution of the µBOX implies digitalising the Signal in over 1 MILLION steps!

Figure2: Sensor Terminal Connector

Figure3: Application Software

Hans Ajiet Holtkamp

Computer based data acquisition was a tedious and time consuming affair until now. A complete acquisition system consisted of many parts which had to be connected with each other and individually configured.

Such systems were not only suceptible to Noise and Error sources; the costs were very high too! Even if individual elements such as the A/D converter itself were affordable, the costs of the complete system were high.

Author:
Dipl.-Phys. Hans Ajiet Holtkamp ist Managing director of the disynet GmbH

With the µBOX this complexity is a thing of the past.

Up to five senors and two additional digital sources are simply connected on one side of the housing using a shielded terminal connector - the other side is connected with a standard USB-Cable to an available USB-plug of a computer. Using the supplied software, the sensor signals can now be acquired, displayed, saved and analysed.

The excitation of the sensors is also supplied by the µBOX. Three of the analog inputs have an integrated amplifier, so that signals from 10mV up to 10V can be accepted.

An external power supply is only necessary if the current consumption is too high. This is indicated by the blinking of an LED.

One for Many

The µBOX replaces many individual modules and is therfore not only easier to use, it also eliminates the source of many errors.

Figure4: Settings

The µBOX can therefore also be used for sensors that have a high resolution - the µBOX is e.g. also used for calibrating sensors!

However, the resolution of 20 Bit only allows an acquisition rate of a few samples per second.

Fast Acquisition

If this high resolution of 20 Bits is not required then acquisition rates of up to 25 kHz, i.e. 25.000 Samples per second can be achieved.

Digital Inputs

The digital inputs permit, for example, connecting Torque Sensors with digital information on rotation speed and angle and recording these values together with the torque.

Control

The µBOX has five Digital Outputs with which can be used for control purposes. For example, it is possible to set thresholds for each channel to trigger alarms when these are crossed.

4 µBOXes with USB-Hub

Up to four µBOXes can be cascaded with a USB-Hub. extending the number of available channels to 20.

disynet GmbH offers a sensor compendium on the Site www.esensors.net
with useful information on Sensoren und Metrology.

Figure5: Online Display

Software und Drivers for popular Software Programs

The µBOX is supplied with software
- to configure the device,
- to acquire, record and display the data - with simple analysis functions - and
- to control external devices, e.g. by setting tresholds.

Sensoren

Customers who have Sensors and a Computer only need the µBOX additionaly.

Sensoren

The software was designed for easy use and handling. Special emphasis was laid on intuitive and easy calibration of the sensors. The calibration is either done by entering values of an existing calibration sheet or online by entering pairs of values (two-point calibration) .

If this functionality is not sufficient, drivers LabVIEW and a dll for developing custom software are available, leaving no bounds on the possibilities.

Figure7: Data Analysis

Figure6: Recording Data

Future

Many additional modules will be available in the near future for the µBOX.

A 10 Bit- analog output of saved signals will be available, allowing the µBOX to be used as an arbitraray signal generator.

An SD-Card slot is being designed which will convert the device into a mobile data-logger.

A module for wireless transmission of data between the µBOX and the computer will expand the possibilities even further.

Additional modules for sensors which are not supported yet are also planned.

As with sensors made to measure by disynet , the development of this device depends on the feedback from the industry.

SUMMARY

With the µBOX disynet has created a professional, universal data acquisition system, which stands out from the rest of the available devices due to easy handling, for a really competitive price.

MADE TO MEASURE

the slodan of disynet GmbH has two meanings:

1) Customized
2) designed to measure

The constant commitment to this slogan, since the Company was founded 11 years ago, has made disynet a synonym of this slogan."