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National Instruments Corporation
17
NI WSN-3212 User Guide and Specifications
WSN Connect Button
Note
Refer to your NI WSN gateway documentation for detailed instructions about how to connect
a NI WSN-3212 to the NI WSN gateway.
The NI WSN-3212 is equipped with a WSN connect button as shown in Figure 13. The button controls
network connection and the LEDs, which display connection status.
Pressing the WSN connect button results in the device responses shown in Table 2.
Reset Button
The NI WSN-3212 is equipped with a reset button as shown in Figure 13.
Pressing the reset button results in the following device responses:
•
When pressed for fewer than 5 seconds, the device reboots with the current configuration.
•
When pressed for 5 seconds or more, the device reboots into Factory Default Mode, which returns
the device user configuration to the factory-set defaults.
Using the NI WSN-3212 Device
Analog Input Circuitry
Terminals 0–7 on the 18-position screw terminal connector are analog input. The NI WSN-3212
channels share a common ground that is not isolated from other system parts. Each channel has some
impedance between the TC+ and COM terminal and between the TC– and the COM terminal. Each
channel is filtered, and then sampled by a 24-bit analog-to-digital converter (ADC). There is a current
source between the TC+ and TC– terminals. If an open thermocouple is connected to the channel, the
current source forces a full-scale voltage across the terminals. Refer to your software documentation for
more information about detecting open thermocouples in software.
Figure 14.
Analog Input Circuitry for One Channel
Table 2.
WSN Connect State/Device Status
Current Device State
Duration of Button Press
Result
Initial power on,
not connected
Any duration
Node turns on and searches for an available network.
Connected to a
NI WSN-9791
<5 seconds
Node blinks all four signal strength LEDs twice, and
then displays the signal strength as shown in Table 1.
≥
5 seconds
Node leaves current network and searches for a new
network.
TC–
10 M
Ω
10 M
Ω
Inp
u
t
Imped
a
nce
Open
Thermoco
u
ple
Detection
C
u
rrent
Filtered
Differenti
a
l
Amplifier
ADC
NI W
S
N-
3
212
TC+
COM
