Chapter 4 Analog Input
NI 6124/6154 User Manual 4-6 ni.com
Analog Input TriggeringAnalog input supports two different triggering actions: start and reference.
An analog or digital hardware trigger can initiate these actions. All S Series
devices support digital triggering, and some also support analog triggering.
To find your device’s triggering options, refer to the specifications
document for your device.
The AI Start Trigger Signal and AI Reference Trigger Signal sections
contain information about the analog input trigger signals.
Refer to Chapter 11, Triggering, for more information about triggers.
Connecting Analog Input SignalsTable 4-1 summarizes the recommended input configuration for different
types of signal sources for S Series devices.
Table 4-1. S Series Analog Input Signal Configuration
Input
Floating Signal Sources
(Not Connected to Earth Ground) Ground-Referenced Signal Sources
Examples:
• Ungrounded thermocouples
• Signal conditioning with isolated
outputs
• Battery devices
Example:
• Plug-in instruments with
non-isolated outputs
NI 6124
Non-Isolated
Differential
(DIFF)
NI 6154
Isolated
Differential
(DIFF)
AI 0+
AI 0–
AI GND
V
1
+
–
+
–
R
V1
AI 0+
AI 0–
AI GND
+
–
+
–
AI+
A I–
Isolation
Barrier
+
–
+
–
AI+
AI–
Isolation
Barrier
+
–
+
–