Floating Differential Connections
1 MΩ
Resistor
NI 9215 with
Screw/Spring
Terminal
AI+
AI–
COM
Voltage
Source
+
–
• Connect the negative lead to COM through a 1 MΩ resistor
to keep the signal source within the common-mode voltage
range.
• The NI 9215 with screw terminal and the NI 9215 with spring
terminal does not read data accurately if the signal source is
outside of the common-mode voltage range.
NI 9215 Getting Started Guide | © National Instruments | 19