Dewetron DAQP-CFB2, Technical Reference Manual

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DAQP-CFB2
General description
The signal path of the DAQP-CFB2 is completely analog. This reduces the signal delay to the absolute
minimum, which is a huge advantage in comparison to a DSP based bridge amplifier with AD and DA
conversion. DSP based bridge amplifiers always have a delay due to the calculation. The analog design
makes the DAQP-CFB2 a perfect choice for control loop applications, where a fast response is required.
The main advantages of the carrier frequency technology are:
eliminating thermo voltages
extremely low 1/f noise
electrical disturbances like the 50/60 Hz signal are totally suppressed
very high offset stability
The typical applications for this module are:
Long term strain measurement
Strain gage measurement in harsh electromagnetic environment
LVDT sensor measurement
Capacitive sensor measurement
Frontend amplifier for control loops
Test-bed signal conditioning
The DAQP-CFB2 replaces the older DAQP-CFB module. The new module has a higher accuracy and
supports many more features. Despite of all improvements, it is still compatible with the older DAQP-CFB.
Even the standard command set, except custom range settings, is downward compatible. Replacing the old
CFB by the new one should not require any changes in terms of sensor connection.
Front panel control
LED indication:
Filter Range Range Filter
B.W. 5 mV/V x100 300 Hz
2 mV/V x10 100 Hz
3000 Hz 1 mV/V x1 30 Hz
10000 Hz Cust. x0.1 10 Hz
The DAQP-CFB series module has a set of 8 LEDs showing the current input range (constant active)
and filter range setting (flashing). Functions are described below.
Push button operation:
Assign module address: Press the ID button for allowing the software to change the address.
Select range : Push the RANGE button several times shortly until the LED displays the
desired input range.
Select Filter: Push the FILTER button once - the LEDs will flash for approx. 3 seconds
and display the current filter setting. Push the FILTER button within the
three seconds several times until the flashing LED displays the desired filter
range.