National Instruments NI 6232 - Manual (Page 39)

Chapter 4 Analog Input
NI 6232/6233 User Manual 4-12 ni.com
Refer to the Analog Input Ground-Reference Settings section for
descriptions of DIFF and RSE modes.
Types of Signal Sources
When configuring the input channels and making signal connections, first
determine whether the signal sources are floating or ground-referenced. For
isolated measurement products, the front ends are isolated from the
building ground system, breaking any electrical connection between the
Table 4-4. Analog Input Configuration
Input
Floating Signal Sources (Not
Connected to Building Ground) Ground-Referenced Signal Sources
Examples:
• Ungrounded thermocouples
• Signal conditioning with isolated
outputs
• Battery devices
Example:
• Plug-in instruments with
non-isolated outputs
Differential
(DIFF)
Referenced
Single-Ended
(RSE)
+
–
+
–
AI +
AI –
Isolation
Barrier
AI GND
+
–
+
–
AI +
AI –
Isolation
Barrier
AI GND
+
–
+
–
AI +
Isolation
Barrier
AI GND
+
–
+
–
AI
Isolation
Barrier
AI GND