Campbell CSAT3B, Product Manual, Page: 64 / 88

CSAT3B Three-Dimensional Sonic Anemometer
56
The
CSAT3B()
instruction should appear in the main scan of the CRBasic
program operating in pipeline mode.
Destination:
This variable will store the values returned by the anemometer. The destination
variable must be declared as a float (default) with at least five elements. The
CSAT3B returns the following data in response to a measurement trigger:
•
u
x
– x-axis wind speed in meters per second (m·s -1 )
•
u
y
– y-axis wind speed in meters per second (m·s
-1
)
• u
z
– z-axis wind speed in meters per second (m·s -1 )
•
T
s
– Sonic Temperature in degrees Celsius (°C)
•
Diagnostic word
Bus:
This parameter determines whether the communications to the CSAT3B are
done via the SDM or CPI bus. A ‘
0
’ indicates SDM and a ‘
1
’ indicates CPI.
This parameter must be a constant. If this is set to ‘
0
’, the OperatingMode
parameter must also be set to ‘
0
’ since the SDM protocol does not support
Mode 1 operation or the use of bandwidth filters.
Address:
This parameter identifies the unique address of the CSAT3B on the
communication bus. For SDM, this number may be in the range of
1
to
14
. For
CPI, this number may be in the range
1
to
120
. This parameter must be a
constant.
OperatingMode:
This parameter controls whether the CSAT3B will operate in Mode 0 or
Mode 1 (see Section 8.2 , Operating Modes
(p. 48)
, for more details). This
parameter must be a constant and may have one of the following values: 0, 5,
10, 20, or 25. The meaning of each of these values is listed below:
• 0 = Mode 0 (open bandwidth, no bandwidth filter)
•
5 = Mode 1 with 5 Hz bandwidth filter
•
10 = Mode 1 with 10 Hz bandwidth filter
• 20 = Mode 1 with 20 Hz bandwidth filter
• 25 = Mode 1 with 25 Hz bandwidth filter
The SDM protocol does not support Mode 1 operation or use of bandwidth
filters. Accordingly, this parameter must be set to ‘
0
’ if the Bus parameter is
set to ‘
0
’. If the Bus parameter is set to ‘
1
’, indicating CPI communications, all
of the defined values are valid.
8.4.1.2 CSAT3BMonitor()
The CSAT3BMonitor() instruction provides auxiliary information pertaining
to the physical condition of the anemometer. This retrieves the internal
temperature and relative humidity of the electronics enclosure, and also the
inclination of the anemometer. The instruction requires three parameters: