National Instruments NI 9411 Operating Instructions And Specifications page 9

measures whether the difference between the DIa and DIb pins is
greater than or less than the digital logic levels. If the difference
between the pins is within the input high range, the channel
registers as high. If the difference between the pins is within the
input low range, the channel registers as low. Refer to the
Specifications
levels. Figure 2 shows a possible configuration.
Differential
Device
Figure 2. Connecting a Differential Device to the NI 9411
NI 9411 Operating Instructions and Specifications
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section for more information about digital logic
External
Power Supply
+
V
sup
+5 V
+5 V
out
Reg
DIa
+
Receiver
DIb
Circuitry
–
COM
8
–
COM
NI 9411
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