'CR1000X Series Datalogger
'Example datalogger program for Apogee Instruments S2-141 series PAR - Far red sensors.
'Date: December 11 2020
'Program author: John Huber

'Wiring:
'White -> High side differential channel 1 (Far red detector)
'Black -> Low side differential channel 1 (Far red detector)
'Yellow -> High side differential channel 2 (PAR detector)
'Blue -> Low side differential channel 2 (PAR detector)
'Clear -> Shield ground

'Explanation of constants and variables used in datalogger program:
'BattV = Datalogger battery voltage (Volts DC).
'PanelT = Datalogger panel temperature (Degrees C).
'PARMult = The calibration factor for the PAR detector (See your sensor's calibration sheet for this number)
'FarRedMult = The calibration factor for the Far red detector (See your sensor's calibration sheet for this number)
    'NOTE: All calibration factors are sensor-specific.  The factors listed in this example program are placeholders used as examples only.
'PARmV = The raw voltage output from the PAR detector in millivolts
'FarRedmV = The raw voltage output from the FarRed detector in millivolts
'PAR = The calibrated PAR reading in umol/m^2/sec for the PAR detector
'FarRed = The calibrated Far red reading in umol/m^2/sec for the Far red detector
'PARFarRed = Ratio of PAR and Far red light

'Declare Public Variables
Public BattV, PanelT
Public PARmV, FarRedmV, PAR, FarRed, PARFarRed

'Declare Constants
'Calibration Coefficients: Refer to your sensor's calibration sheet and change these to match.
Const PARMult = 70
Const FarRedMult = 50

'Define Data Tables.
DataTable (PARFar,1,-1) 
	DataInterval (0,1,Min,10)
	Minimum (1,BattV,FP2,False,False)
	Sample (1,PanelT,FP2)
	Average(1,PAR,IEEE4,False)
	Average(1,FarRed,IEEE4,False)
	Average(1,PARFarRed,IEEE4,False)
EndTable

'Main Program
BeginProg
	Scan (1,Sec,0,0)
		PanelTemp (PanelT,60)
		Battery (BattV)
		'Measure detector output voltages
		VoltDiff(FarRedmV,1,mV200,1,True,0,_60Hz,1.0,0.0)
		VoltDiff(PARmV,1,mV200,1,True,0,_60Hz,1.0,0.0)
		'Apply Calibration Factors
		PAR = PARmV * PARMult
		FarRed = FarRedmV * FarRedMult
		'Calculate the PAR-Far red ratio
		PARFarRed = PAR / FarRed
		CallTable PARFar
	NextScan
EndProg