Function description
Operating Manual PSSu E S 2AI I se(-T)
21417-EN-04
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4.3.2
Digital filter
A digital filter can suppress spurious frequencies in the input signals.
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FIR filters specifically suppress certain spurious frequencies (notch mode). In this way,
for example, the residual ripple from the power supply can be filtered out of the input
signal.
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IIR filters suppress all frequencies above a cutoff frequency (low pass mode). This
means that short-term fluctuations can be filtered out of the input signal.
You can select one of the following filters per module:
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2nd order FIR filter
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IIR filter, cutoff frequency 1 kHz
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IIR filter, cutoff frequency 100 Hz
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IIR filter, cutoff frequency 50 Hz
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IIR filter, cutoff frequency 20 Hz
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IIR filter, cutoff frequency 10 Hz
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IIR filter, cutoff frequency 5 Hz
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IIR filter, cutoff frequency 1 Hz
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FIR filter, notch frequency 50 Hz
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FIR filter, notch frequency 60 Hz
The filter is deactivated as the default value.
INFORMATION
A filter needs time to make the calculation and this increases the module's
processing time.
4.3.3
Limit values
The module has range monitoring and limit value monitoring on each channel:
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Range monitoring
– Upper limit value: 4095
D
– Lower limit value: -4095
D
– The module compares the upper and lower limit value with the digital value after the
hardware calibration (values with 12 bits plus sign) and writes the result of the com-
parison as follows:
– System environment A:
– In the status byte (see "PSSu assignment in system environment A")
– System environment B:
– In the I/O data element "Overrange" or "Underrange" (see "PSSu assignment in
system environment B").
– The limit of the measuring range corresponds to 4095
D
.
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Limit value monitoring
– Limit value 1