Chapter 3
Connecting Signals
SCB-68 Shielded Connector Block User Manual
3-2
ni.com
Figure 3-1.
Summary of AI Connections
+
–
+
–
+
–
V
1
ACH
AISENSE
AIGND
+
–
+
–
V
1
ACH
AIGND
+
–
+
–
V
1
ACH(+)
ACH(–)
AIGND
+
–
+
–
V
1
ACH(+)
ACH(–)
AIGND
R
Refer to the
Using Bias Resistors
section for information on bias resistors.
Signal Source Type
Floating Signal Source
(Not Connected to Building Ground)
Grounded Signal Source
Examples:
• Ungrounded thermocouples
• Signal conditioning with
Isolated outputs
• Battery devices
Examples:
• Plug-in instruments with
nonisolated outputs
Input
Differential
(DIFF)
Single-Ended —
Ground
Referenced
(RSE)
Single-Ended —
Nonreferenced
(NRSE)
+
–
+
–
+
–
Common-
Mode
Voltage
Common-
Mode
Voltage
Common-
Mode
Voltage
+
–
Common-
Mode
Voltage
+
–
Common-
Mode
Voltage
Common-
Mode
Voltage
Refer to the
Using Bias Resistors
section for information on bias resistors.
+
–
+
–
V
1
ACH
+ V
g
–
AIGND
Ground-loop losses, V
g
, are added to
measured signal.
NOT RECOMMENDED
+
–
+
–
V
1
ACH
AISENSE
AIGND
R
