National Instruments 6008 - Manual (Page 14)

NI USB-6008/6009 User Guide and Specifications 14 ni.com
The differential input mode can measure
±20 V signals in the ±20 V range.
However, the maximum voltage on any one pin is
±10 V with respect to
GND. For example, if AI 1 is
+10 V and AI 5 is –10 V, then the
measurement returned from the device is
+20 V.
Figure 8. Example of a Differential 20 V Measurement
Connecting a signal greater than
±10 V on either pin results in a clipped
output.
Figure 9. Exceeding
±
10 V on AI Returns Clipped Output
–5
–10
–15
–20
20
15
10
5
0
Amplitude (V)
AI 1
AI 5
Result
–5
–10
–15
–20
20
15
10
5
0
Amplitude (V)
AI 1
AI 5
Result