Vaisala WS425 - Manual (Page 48)

USER'S GUIDE____________________________________________________________________
48 __________________________________________________________________ M210361EN-E
The microprocessor translates this circular function to a linear function,
that is, 359° + 5° is translated to 364° and
0° - 5° translates to - 5°.
To calculate the scalar average wind direction, each translated wind
direction measurement taken over the preceding averaging interval is
summed and the sum is divided by the number of measurements.
Vector Averaging
Each x velocity and y velocity measurement over the averaging interval
is added and then divided by the number of measurements. The resulting
average x velocity and average y velocity are converted to polar direction
and magnitude, returning as average direction in degrees and speed in the
chosen units.
Output Interval
The output interval can be selected in full seconds between 1 and 9
seconds. These settings are independent of the averaging interval
(configuration parameter 3, see section Average Interval on page 47).
Regardless of the length of the output interval, the last measurement
sample before transmission is always the last sample of the averaging
window. Therefore, the transmitted data is always based on the latest
measurements.
If the output interval is set to zero (0), polling is used in data acquisition.
NOTE When using the NMEA Standard as the operating mode (configuration
parameter 1), there must be a non-zero setting for output interval since
polling is not supported in the NMEA Standard mode.
Sensor ID Character
The sensor ID character must be a single capital letter from A to Z.
Numbers or small letters are not accepted. After an ID is defined for a
sensor, the configuration menu can be opened by typing open <id>.
This is useful if several sensors are sharing the same communication line.
When running the NMEA Extended or WAT11 mode, the sensor ID is
part of the polling string.