National Instruments NI 6120 用户手册

© National Instruments Corporation

Figures 4-4 and  4-5 show how to connect a floating signal source to a 
channel on the NI 6115 and NI 6120, respectively.

Figure 4-4.  Differential Input Connections on the NI 6115 for Nonreferenced Signals

+

–

ACH0 Connections Shown

PGIA

1 M

*

100 pf

*

10 nf

Bias
Resistor 
(see text)

AC Coupling

V

m

I/O Connector

Bias

Current

Return

Paths

Floating

Signal

Source

Instrumentation

Amplifier

Measured

Voltage

ACH0GND

ACH0–

ACH0+

+

–

*

10 k

Ω

40 pf 

for ranges > ±10 V

V

s

+

–

Common-Mode

Choke