National Instruments SCB-68 User Manual page 30

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