Campbell Scientific SR50-L CSC Ultrasonic Distance Sensor - Manual (Page 34)

Appendix A. Making Concurrent Measurements with the SR50
A- 2
Place measurement in Loc X.
If measurement is > -1000 then use measurement
Else
Add 1 to a counter
If the counter = 3 (means there were 3 bad readings in a row) then do:
Use bad reading for measurement.
Reset counter.
Example Program:
In this example, an SR50 is mounted 2 meters above the ground. Snow depth
and measurement quality numbers are the desired output. This program uses
Instruction 105 (refer to Section 9 in the CR10X manual for details on P105
SDI-Recorder Instruction) to obtain a distance measurement from the SR50.
The SR50’s address is 0. It is assumed that a Campbell Scientific 107
Temperature Probe is being used and that the SR50 SDI-12/DATA Bus line
(green wire) is wired to control port 1(see Figure 2, page 6 for wiring
diagram).
;{CR10X}
;
*Table 1 Program
01: 5
Execution Interval (seconds)
1: Temp (107) (P11)
; Measure air temperature
1: 1 Reps
2: 1 SE Channel
3: 1 Excite all reps w/E1
4: 1 Loc [ AIR_TEMP ]
5: 1 Mult
6: 0 Offset
2: Z=X+F (P34)
; Convert Celsius reading to Kelvin
1: 1 X Loc [ AIR_TEMP ]
2: 273.15 F
3: 2
Z Loc [ T_KELVIN ]
; Measure the SR50 using Concurrent Measurement ability...
3: SDI-12 Recorder (P105)
1: 0
SDI-12 Address
2: 1 -- Start Measurement (aM1!) ; <<<< Configured to provide distance with
3: 1 Port ; echo quality numbers and do concurrent measurement
4: 3 Loc [ Raw_Dist ]
5: -1.0 Mult
6: 0.0 Offset
; Check to see if a valid measurement has been returned, and if it has, move
; the measurement to another Input Location to be used as data and reset the
; failure counter.