ES415.1 - User’s Guide
21
ETAS
Hardware Description
4.3
Sensor Channels
All sensor channels of the ES415.1 are identical. Every sensor channel consists of
the function groups Signal Processing and Filter as well as Sensor Power Supply.
4.3.1
Signal Processing and Filters
Fig. 4-3
Signal Processing and Filters of a Sensor Channel
4.3.2
Amplifier and analog Filter
The level of the input signal is limited in every sensor channel after the overvolt-
age protection by a capacitively compensated voltage divider. An amplifier
adjusts the input signal to the following analog anti-aliasing filter according to
the selection of the input voltage range. This 4th order analog filter with Butter-
worth characteristics has a cutoff frequency of 50 kHz.
4.3.3
A/D Converter
An A/D converter digitizes the output signal of the analog filter. The individual A/
D converter available in every sensor channel guarantees synchronous sampling
of the measure signals.
Sample Rates for Rapid Prototyping Applications
Sample rates to 10 kHz can be configured for measurement and calibration
applications as well as for Rapid Prototyping applications in the application soft-
ware.
To avoid the IRQ overload at the I/O port of the ES910.3, the sample rate of the
ES415.1 module in this mode is automatically limited to 10 kHz.
If the ES415.1 would be operated at high sample rates for Rapid Prototyping
applications, the ES910.3 could no longer process the data of the ES415.1 or
other ETAS daisy chain modules due to IRQ overload at its I/O port and would
discard the data.
Note
For Rapid Prototyping applications, the sample rate of the ES415.1 module is
limited to a maximum of 10 kHz. The sample rates 100 kHz, 50 kHz and
20 kHz are available only for measurement and calibration applications.
Bypass
f
C,FIR
Analog
Input
+
Lowpass
Filter
A
D
Adjustable
Gain
A/D
Converter
Analog
Input
‐
Voltage
Range
f
C,AAF
f
S,AD
Control
Digital
Filter,
Decimator
Buffer
Sample
1
Sample
2
Sample
3
Sample
n
f
S,INCA
CTRL
ADC