User manual

Chapter 3 Signal Conditioning
BNC-2090A User Manual 3-12 ni.com
Notice that the input impedance for the channels employing voltage
dividers circuit is reduced. In the differential example in Figure 3-9,
the input impedance has been reduced to:
10 kΩ + 10 kΩ + 10 kΩ = 30 kΩ
The reduced input impedance can cause loading errors for signal sources
with large source impedance. In general, the input impedance presented by
the voltage divider circuit must be much larger than the source impedance
of the signal source to avoid signal loading errors.
Analog Output Signal Conditioning
Each analog output has two open-component positions for passive signal
conditioning components. One is designated as a resistor and one is
designated as a capacitor. Factory-default positions for the 0 Ω jumpers are
R34 and R1 as shown in Figure 3-11.
Figure 3-11. AO 0 and AO 1
You can remove and/or install components in these locations to build
highpass and lowpass filters. Refer to the Adding Signal Conditioning
Components section for instructions.
R1
C2
R34
C1
AO 1
BNC Connector
AO 0
BNC Connector
AO GND
AO 1
AO 0
From
DAQ Device
From
DAQ Device
Factory-Installed
0 Ω Jumper
Factory-Installed
0 Ω Jumper
AO GND