Programming instructions

Chapter 5 Things You Should Know about Analog Input
© National Instruments Corporation 5-9 LabVIEW Data Acquisition Basics Manual
Differential Measurement System
In a differential measurement system, you do not need to connect either
input to a fixed reference, such as earth or a building ground. DAQ devices
with instrumentation amplifiers can be configured as differential
measurement systems. Figure 5-7 depicts the 8-channel differential
measurement system used in the MIO series devices. Analog multiplexers
increase the number of measurement channels while still using a single
instrumentation amplifier. For this device, the pin labeled AIGND
(the analog input ground) is the measurement system ground.
Figure 5-7.
8-Channel Differential Measurement System
+
+
CH0–
CH2–
CH1–
CH7–
CH0+
CH2+
CH1+
CH7+
MUX
MUX
Vm
Instrumentation Amplifier
AIGND
–
–