NI WSN-3214, User Manual And Specifications

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© National Instruments 29 NI WSN-3214 User Guide and Specifications
When powering the NI WSN-3214 from a floating power supply source like an external battery or
isolated power supply, the measurements are susceptible to picking up noise. National Instruments
recommends connecting the shield of the cable to both the mounting plate of the strain-gage or the metal
casing of a bridge-based sensor and the DGND pin on the NI WSN-3214. Or, connect the DGND pin
on the NI WSN-3214 to Earth GND.
Figure 27. Quarter-Bridge Measurements Supplied From a Floating Power Supply
Figure 28.
Quarter-Bridge Measurements Supplied From an Earth GND Referenced Supply.
Controlling Digital Inputs and Outputs
The following sections discuss how to configure the NI WSN-3214 device for different types of input
and output, and how to connect external devices to the NI WSN-3214 DIO terminals.
On the 36-position screw terminal connector, terminals 16–18 and 34–36 are the DIO section. The DIO
section has the following terminals:
• DIO x —signal terminal
• DGND—ground terminal
• DIO PWR—DIO Power positive (required when one of the DIO channels is configured for Drive
High (Sourcing) or Drive High and Low (Sinking and Sourcing) mode)
EX+
IN+
V
C
R
COMP
/EX–
DGND
NI W S N- 3 214
+
–
C ab le
S hield
Mo u nting
Su rf a ce
S tr a in
G a ge
EX+
IN+
V
C
R
COMP
/EX–
DGND
NI W S N- 3 214
E a rth GND
Reference
Su pply
+
–
C ab le
S hield
Mo u nting
Su rf a ce
S tr a in
G a ge