Campbell Scientific SR50-L CSC Ultrasonic Distance Sensor - Manual (Page 19)

SR50 Sonic Ranging Sensor
13
The following instructions set the sensor enable line high long enough for the
SR50 to detect it, then set it low.
1: Set Port (P20)
1: 1
Set High
2: 1 Port Number
2: Excitation with Delay (P22)
1: 1
Ex Chan
2: 1 Delay w/Ex (units = 0.01 sec)
3: 0000 Delay After Ex (units = 0.01 sec)
4: 0.0 mV Excitation
3: Set Port (P20)
1: 0
Set Low
2: 1 Port Number
The P3 instruction counts the pulse train being transmitted from the SR50.
Distance-to-surface will automatically be reset to 0.00 after the distance is
calculated and stored for later processing and output.
4: Pulse (P3)
1: 1
Reps
2: 1 Pulse Input Chan
3: 00 Config Option
4: 21 Loc [ Dis2Surf ]
5: -.0025 Mult
6: 0.0
Offset
Measure air temperature and convert to degrees Kelvin. This example assumes
air temperature is being measured with Campbell Scientific’s Model 107
probe.
5: Temp 107 Probe (P11)
1: 1
Reps
2: 1 In Chan
3: 1 Excite all reps w/Exchan 1
4: 22 Loc [ T_Kelvin ]
5: 1 Mult
6: 273.15 Offset
Compute the air temperature compensation factor and correct the distance-to-
surface for air temperature (see formula 1).
6: Z=F (P30)
1: 273.15 F
2: 23
Z Loc [ 273_15 ]
7: Z=X/Y (P38)
1: 22
X Loc [ T_Kelvin ]
2: 23 Y Loc [ 273_15 ]
3: 24 Z Loc [ ATempComp ]