Theory Of Operation - National Instruments SCC-FV01 User Manual

Theory of Operation

Signal
Source
4
+
–
3
2
+
–
1
SCC-FV01 Frequency Input Module User Guide
Figure 2 illustrates the key functional components of the SCC-FV01.
Comparator
Comparator
Triggering
Stage
Figure 2. SCC-FV01 Signal Connections
The SCC-FV01 has two input channels designed to measure 0 to 100 Hz
signals. The output voltage (0 to 10 VDC) varies linearly with respect to the
input frequency.
The frequency-to-voltage and analog circuitry for each channel consists of
a triggering stage, a frequency-to-voltage stage, and an output stage.
3 Hz
Frequency-
Butterworth
to-Voltage
Filter
3 Hz
Frequency-
Butterworth
to-Voltage
Filter
F-V Output
Stage Stage
10
AI ( X )
AI SENSE
AI GND
AI ( X +8)
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