Campbell 05103, Руководство пользователя

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User Manual
11
Table 7-1. Wire Colour, Wire Function, and Datalogger Connection
Wire
Colour
Wire
Function
Datalogger Connection Terminal
Red WS Signal U configured for pulse input
1
, (pulse input),
Or P_LL (pulse, low-level ac)
Black WS Signal
Reference
Green
WD Signal
U configured for single-ended analogue input
1
,
SE (single-ended, analogue input)
Blue WD Voltage
Excitation
U configured for voltage excitation
1
, EX, or
VX (voltage excitation)
White WD Signal
Reference
(analogue ground)
Clear Shield (analogue ground)
1
U channels are automatically configured by the measurement instruction.
7.4 Programming
This section is for users who write their own programs. A datalogger program to
measure this sensor can be created using Campbell Scientific’s SCWin Short Cut
Program Generator software. You do not need to read this section to use Short
Cut.
7.4.1 Wind Speed
For CRBasic dataloggers, wind speed is measured using the PulseCount()
instruction. Syntax of the PulseCount() instruction is:
PulseCount( Dest, Reps, PChan, PConfig, POption, Mult, Offset )
The PConfig parameter should be set to 1 (Low Level AC) and the POption
parameter should be set to 1 (Frequency) .
For Edlog dataloggers, wind speed is measured using Edlog instruction Pulse
(P3) . The configuration parameter should be set to code 21 (Low Level AC,
Output Hz configuration).
The expression for wind speed (U) is:
U = Mx + B
where
M = multiplier
x = number of pulses per second (Hertz)
B = offset
Table 7-2 lists the multipliers to obtain miles/hour or metres/second when the
measurement instruction is configured to output Hz.
The helicoid propeller has a calibration that passes through zero, so the offset is
zero (Gill, 1973; Baynton, 1976).