Vaisala WS425 - Manual (Page 43)

Chapter 4 ________________________________________________________________ Operation
VAISALA _______________________________________________________________________ 43
Measurement Unit Change Command Ux
The measurement unit change command is Ux.
where
x = 0, for miles per hour, [mph]
x = 1, for knots (default), [knot]
x = 2, for kilometers per hour, [km/h]
x = 3, for meters per second, [m/s]
The following is an example: U3
It sets meters per second for wind speed.
NMEA Standard
The standard variable length, comma-separated, MWV wind message is
defined by NMEA 0183 V2.20 as follows:
$WIMWV,<dir>,<ref>,<spd>,<uni>,<sta>*<chk><cr><lf>
where
$WIMWV = Fixed text
<dir> = Wind angle, 0 to 359 degrees
<ref> = Reference; R=Relative, T=True
<spd> = Wind speed
<uni> = Wind speed units; K = kmph [km/h],
M = mps [m/s], N = kt
<sta> = Status; A = Data Valid, V = Invalid Data
* = Fixed text
<chk> = Checksum
(8-bit XOR, excluding $ and *)
<cr> = Carriage return code, ASCII 0DH
<lf> = Line feed code, ASCII 0AH
NOTE When the NMEA Standard message format is selected, the sensor
must have a non-zero output interval setting (parameter 5 in the
configuration menu) since no polling command is defined for this
message type.