SECTION 3. PROGRAMMING
3-2
TABLE 3-2. Parameters for Sensor Measurement Instruction
Instr.
Input Input
Range
Excit
Sensor
Measurement
No.
Ch.
Code
mV
Ch
mV
Temperature
AC Half Bridge
11
1S
N/A
N/A
1
2000
Relative Humidity
DC Half Bridge
4
4S
5
2500
2
0000
Solar Radiation
Diff. Voltage
2
3D
2
7.5
N/A
N/A
Wind Speed
Frequency
3
1
N/A
N/A
N/A
N/A
(AC Magnetic)
Wind Direction
Half Bridge
4
3S
5
2500
2
2500
Rain
Contact Closure
3
2
N/A
N/A
N/A
N/A
Moisture Index
AC Half Bridge
5
12S
13
25
3
2500
S = Single Ended Analog Channel
D = Differential Analog Channel
3.1.1. TEMPERATURE AND RELATIVE
HUMIDITY
The thermistor is read using Instruction 11.
The RH sensor is read using Instructions 20
and 4. Instruction 20 switches 12 V to the RH
sensor; Instruction 4 delays 80 ms then makes
the measurement. Instruction 20 is used again
to switch the 12 V off. Instructions 37 and 34
convert the temperature to degrees F and put it
into location 5.
03:
P11
Temp 107 Probe
01:
1
Rep
02:
1
IN Chan
03:
1
Excite all reps w/EXchan 1
04:
4
Loc [:temp C ]
05:
1
Mult
06:
0
Offset
04:
P37
Z=X*F
01:
4
X Loc temp C
02:
1.8
F
03:
5
Z Loc [:temp F ]
05:
P34
Z=X+F
01:
5
X Loc temp F
02:
32
F
03:
5
Z Loc [:temp F ]
06:
P20
Set Port(s)
01: 0000
C8..C5=low/low/low/low
02: 1000
C4..C1=high/low/low/low
07:
P4
Excite,Delay,Volt(SE)
01:
1
Rep
02:
5
2500 mV slow Range
03:
7
IN Chan
04:
2
Excite all reps w/EXchan 2
05:
80
Delay (units .01sec)
06: 0000
mV Excitation
07:
6
Loc [:RH ]
08:
.1
Mult
09:
0
Offset
08:
P20
Set Port(s)
01: 0000
C8..C5=low/low/low/low
02: 0000
C4..C1=low/low/low/low
3.1.2 WIND SPEED
The wind speed sensor is read by pulse count
Instruction 3, programmed for low level AC and
to measure frequency. The relationship
between wind speed, ws, and frequency, f, for
the R.M. Young Wind Sentry is:
ws = 1.677f + 0.4
where ws has units of mph and f is in Hz. The
result is placed in location 8. If the result equals
the anemometer offset (0.4 mph), the wind
speed value is set to 0; i.e., when there is no
wind speed the offset is not used in the wind
vector calculations.
10:
P3
Pulse
01:
1
Rep
02:
1
Pulse Input Chan
03:
21
Low level AC; Output Hz.
04:
8
Loc [:WS mph ]
05:
1.677
Mult
06:
.4
Offset
11:
P89
If X<=>F
01:
8
X Loc WS mph
02:
1
=
03: .
4
F
04:
30
Then Do
Содержание 012
Страница 1: ...012 WEATHER STATION OPERATOR S MANUAL REVISION 9 91 COPYRIGHT c 1989 1991 CAMPBELL SCIENTIFIC INC...
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Страница 18: ...SECTION 2 WEATHER STATION INSTALLATION 2 8 FIGURE 2 5 2 Battery AC Charging Connections...
Страница 20: ...SECTION 2 WEATHER STATION INSTALLATION 2 10 FIGURE 2 6 1 RAD Modem Connections...
Страница 21: ...SECTION 2 WEATHER STATION INSTALLATION 2 11 FIGURE 2 6 2 Phone Modem Connections...
Страница 22: ...SECTION 2 WEATHER STATION INSTALLATION 2 12 FIGURE 2 6 3 012 Weather Station with Radio Antenna...
Страница 23: ...SECTION 2 WEATHER STATION INSTALLATION 2 13 FIGURE 2 6 4 012 Weather Station with Storage Module...
