TDR SOIL MOISTURE MEASUREMENTS
9
07:
P70
Sample
01:
8
Reps
02:
1
Loc WATER #1
08:
P
End Table 1
*
A
Mode 10 Memory Allocation
01:
28
Input Locations
02:
540
Intermediate Locations
6.2 EXAMPLE 2, HOURLY AVERAGE USING
TOPP'S CALIBRATION
In this example measurements are made every
15 minutes and the average is output each
hour.
Note that Instruction 92, that sets the output
flag, is placed ahead of Instruction 100.
Instruction 92 has to be executed within the
specified minute in order to execute the
command. If it were after Instruction 100, the
actual time of execution would be a minute or
more after the even 15 minute interval on which
the table is executed (i.e., Flag 0 would never
be set).
This program uses Topp's calibration. A
multiplier of 1 and an offset of 0 results in output
of 1/Vp from Instruction 100. This result is
squared and multiplied by 0.1 before being
operated on by the polynomial. The factor of
0.1 allows the coefficients for the polynomial to
be scaled so all significant digits can be entered
in the polynomial Instruction 55.
*
1
Table 1 Programs
01:
900
Sec. Execution Interval
Every 15 minutes
01:
P92
If time is
01:
0
minutes into a
02:
60
minute interval
03:
10
Set high Flag 0 (output)
02:
P77
Real Time
01:
110
Day,Hour-Minute
03:
P86
Do
01:
44
Set high Port 4
04:
P22
Excitation with Delay
01:
1
EX Chan
02:
0
Delay w/EX (units=.01sec)
03:
500
Delay after EX (units=.01sec)
04:
0
mV Excitation
05:
P100
SDM-1502
01:
11
Address
02:
0
Moisture
03:
.3
Probe length (meters)
04:
0
Cable length (meters)
05: 1008
MMMP--Mux channels & Probes
06:
1
Loc [:Wv #1 ]
07:
1
Mult
08:
0
Offset
06:
P86
Do
01:
54
Set low Port 4
07:
P87
Beginning of Loop
01:
0
Delay
02:
8
Loop Count
08:
P36
Z=X*Y
01:
1--
X Loc Wv #1
02:
1--
Y Loc Wv #1
03:
1--
Z Loc [:Wv #1 ]
09:
P37
Z=X*F
01:
1--
X Loc Wv #1
02:
.1
F
03:
1--
Z Loc [:Wv #1 ]
10:
P95
End
11:
P55
Polynomial
01:
8
Reps
02:
1
X Loc Wv #1
03:
1
F(X) Loc [:Wv #1 ]
04:
-0.053
C0
05:
.292
C1
06:
-0.055
C2
07:
0.0043
C3
08:
0
C4
09:
0
C5
12:
P71
Average
01:
8
Reps
02:
1
Loc Wv #1
13:
P
End Table 1
*
A
Mode 10 Memory Allocation
01:
28
Input Locations
02:
550
Intermediate Locations
