©
National Instruments Corporation
16
NI WSN-3226 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-3226 to the NI WSN gateway.
The NI WSN-3226 is equipped with a WSN connect button as shown in Figure 12. 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-3226 is equipped with a reset button as shown in Figure 12.
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-3226 Device
Analog Input Circuitry
The NI WSN-3226 supports two modes: voltage and 3-wire resistance/RTD mode. These modes are
selectable per channel. Inputs are sampled with 20 bits of digital resolution, but effective resolution
depends upon noise. The noise varies according to filter settings.
The NI WSN-3226 supports the ability to digitally filter the analog input in order to reject powerline
noise from the measured signal. The node can enable rejection for 50 Hz, 60 Hz, or both frequencies,
making it flexible for different environments where the powerline energy frequency may not be known.
The node can also be programmed in one of two filtering strength modes: low power mode or high
rejection mode. High rejection mode allows for better noise rejection at the expense of higher energy
per measurement consumed by the node. If the powerline noise frequency is known, it is desirable to
configure the filter to reject only that frequency instead of both 50 Hz and 60 Hz, since the latter will
consume more energy per measurement than only 50 Hz or only 60 Hz rejection. When powerline
filtering is disabled, logic in the node still performs filtering, but at higher frequencies. With powerline
filtering disabled, a filtering strength of high rejection is recommended for the best resolution.
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 or
NI 9792
<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.
