Campbell 21X Operator's Manual page 82

SECTION
8.
PROCESSING
AND PROGRAM CONTROL EXAMPLES
While of questionable value because
of
current
requirements and strip
chart reliability, some
archaic regulations require strip chart backup
on
weather
data. The
SDM-AO4 may be used with
the 21X
to provide an additional four continuous
analog outputs for strip
charts. The
output
values
in
this example are wind speed, wind
direction,
ai
r
tempe rature, and
so
larradiation.
lnstruction 103 is used to activate the
SDM-AO4.
The 4 millivolt values to output must be stored
in
adjacent Input Storage locations, the first
of
which is referenced in Instruction
103.
The
following program measures the sensors
every 5 seconds. The readings are moved to
another
4 locations and scaled to
a 0
to 1000
millivolt output for
the SDM-AO4. Wind direction
is
changed from a 0-360 degree input to output
representing
0
to 540
degrees.
This conversion
is done in a
subroutine which
is described in the
next example.
The example also includes instructions to
output wind vector and average temperalure
and
solar radiation every
hour.
Input location Assignments:
1:WS
2:0-360 WD
3:Ta
4:SR
S:WS
output
6:0-540 out
7:Ta output
8:SR output
10:0-540 WD
Table
1
Programs
Sec, Execution Interval
Pulse
Rep
Pulse Input Chan
Switch closure; Output
Hz.
Loc
[:WS
1
Mult
Offset
Excite, Delay,Volt(S
E)
Rep
500 mV fast Range
lN Chan
Excite all reps w/EXchan
1
Delay (units .01sec)
06:
1000
07:
2
08:
.72
09:
0
mV Excitation
Loc [:0-360 WD
]
Mult
Offset
Temp 107 Probe
Rep
lN Chan
Excite all reps w/EXchan
2
Loc
[:Ta
1
Mult
Offset
Volt (DIFF)
Rep
15
mV slow Range
03:
P11
01:
1
02:
2
03:
2
04;
3
05:
1.8
06:
32
04:
P2
01:
1
02:
2
.-.'03:
3
04:
4
05:
06:
0
05:
P92
01:
0
02:
60
03:
10
06:
P54
01:
4
02:
1
03:
1
04:
5
lN Chan
Loc [:SR
.14493
Mult
Otfset
*1
01:
5
01:
P3
01:
1
02:
1
03:
22
04:
1
05:
1.789
06:
1
09:
P103
01:
4
02:
30
03:
5
02:
P4
01:
1
02:
14
03:
1
04:
1
05:
2
05:
1
07:
P86
01:
1
08:
P53
01:
5
02:
10
03:
0
04:
1.8519
05:
0
06: I
07:
25
08:
1000
09:
0
10:
P92
01:
0
lf
time
is
minutes into
a
minute interval
Set high Flag 0 (output)
Block Move
No. of Values
First Source Loc WS
Source Step
First Destination Loc [:WS
outputl
Destination Step
Do
CallSubroutine
1
Scaling
Array (A.loc +B)
Start Loc [:WS output]
A1
B1
A2
B2
A3
B3
A4
B4
SDM-Ao4 (OSX-o,-1)
Reps
Address
Loc WS output
lf
time
is
minutes into
a
8-6