Campbell Scientific SR50A Distance Sensor - Manual (Page 39)

SR50A Sonic Ranging Sensor
'Subtract the corrected distance from the initial distance of the SR50A to the ground:
Snow_Depth=Initial_Distance - Dist_To_Snow
'Call Data Table and Store Data:
CallTable (Table1)
NextScan
EndProg
10.2.3 CR10X Example (SDI-12 “M3!”)
;{CR10X}
;
;In this example, the SR50AT is mounted 2.5 meters above the ground.
;
;The CR10X sends an SDI-12 command to the SR50AT, which outputs the
;temperature compensated distance value (Meters),
;the signal quality value and the temperature.
;
;Three input locations are used to store incoming data.
*Table 1 Program
01: 60
Execution Interval (seconds)
;Use SDI-12 command "M3!" to receive Distance, Signal Quality and Temperature
1: SDI-12 Recorder (P105)
1: 0
SDI-12 Address
2: 3 Start Measurement (aM3!)
3: 1 Port ;Use Ports 5-8 for CR23X
4: 3 Loc [ SR50ATDIS ]
5: 1.0 Multiplier
6: 0.0 Offset
;Set the initial distance from the SR50A to the ground in meters:
2: Z=F x 10^n (P30)
1: 2.5
F
2: 00 n, Exponent of 10
3: 2 Z Loc [ DisToGnd ]
;Subtract the Distance to the snow surface from the Distance to Ground
;to obtain snow depth
3: Z=X-Y (P35)
1: 2
X Loc [ DisToGnd ]
2: 3 Y Loc [ SR50ATDIS ]
3: 6 Z Loc [ SnowDepth ]
;Hourly Data Output
4: If time is (P92)
1: 0
Minutes (Seconds --) into a
2: 60 Interval (same units as above)
3: 10 Set Output Flag High (Flag 0)
5: Set Active Storage Area (P80)^27063
1: 1
Final Storage Area 1
2: 60 Array ID
33