Campbell Scientific Wireless Sensor Network (CWB100, CWS220, and CWS900) - Manual (Page 49)

Wireless Sensor Network
Distilled water or alcohol works well for most dust/dirt. Salt deposits dissolve
better in a weak acid solution (~0.1 molar).
Sensors connected to the CWS900 may require regular maintenance and
recalibration. See the documentation for the sensor of interest for
recommended maintenance and recalibration details.
7.1 Replacing a Sensor in the Network
If a sensor in the network needs to be replaced, the CWB100 treats the
replacement sensor as a new sensor because it has a different radio address than
the original sensor. The data transmitted by the replacement sensor will have
the same field names as the original sensor, but with a ~ appended to each
name by the datalogger support software to make it unique. The original
sensor will still appear in the final storage data file with NAN’s instead of
values because the sensor is no longer working. Data from the replacement
sensor will be saved to a different position in the final storage data file with
field names that include the ~ character.
If a sensor has not responded to six polls by the CWB100 and it has been more
than two hours since the last communication, the CWB100 will stop polling
that sensor.
The only way to fully remove a sensor from the network and replace it with
another is to force the datalogger to read the sensor names from the CWB100
after the replacement sensor is configured and installed. Changing the size of
the array or the scan interval in the datalogger program, for example, will force
that reading when the program is compiled. In that case the ~ character will
not be appended to the new sensor’s field names.
If a configuration file or string is used in the CWB100( ) instruction, then the
replacement sensor is accommodated by using a new file or string that has the
old radio address replaced with the new radio address. The configuration file is
only read by the datalogger one time at compile, so a change to the
configuration file must be accompanied by a restart of the datalogger program
for the new file to be used.
7.2 Stopping or Loading a New Datalogger Program
If the datalogger program is stopped or a new program loaded, the CWB100
base station will still retain its information for the discovered sensors in the
network. The sensors will not have to initiate auto-discovery.
If the sensors are not polled by the base at least once in 13 hours, the sensors
will initiate the auto-discovery process just as if the Setup button had been
pressed to start auto-discovery.
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