ADLINK Technology NuDAQ PCI-9222, Руководство пользователя

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Hardware Information 23
Figure 2-5 shows how to connect a floating signal source to the
PCI-9222/PCI-9223 card in differential input mode. For floating
signal sources, you need to add a resistor at each channel to
provide a bias return path. The resistor value should be about
100 times the equivalent source impedance. If the source
impedance is less than 100 ohms, you can simply connect the
negative side of the signal to AIGND as well as the negative
input of the instrumentation amplifier without any resistors. In
differential input mode, less noise couples into the signal con-
nections than in single-ended mode.
Figure 2-5: Floating Source and Differential Input
AIxH
AIxL
x = 0, ..., 31
Ground
Referenced
Signal
Source
To A/D
Converter
AIGND
+
-
Instrumentation
Amplifier
+
-
Input Multipexer