Campbell Scientific CDM-VW300 Series Dynamic Vibrating-Wire Analyzer System - Manual (Page 109)

Appendix G. CRBasic Program Library
'Now shift the given Strain using the Baseline/Offset value
Strain(1) = Strain(1) + StrainBL(1) : Strain(2) = Strain(2) + StrainBL(2)
'Zeroing calibration for Geokon 4000 Vibrating Wire Strain Gage
'Strain offset and Temperature baseline readings
FieldCal(0,Strain(),2,0,StrainBL(),ZeroMode,0,1,100) 'Calibrate for 2 seconds
FieldCal(4,Temp(),2,0,TempBL(),ZeroMode,0,1,100)
'Process the Diagnostic codes to keep an eye on the health of the monitored date
ExciteStr(1) = ( DCode(1) AND 255) * VoltFactor : ExciteStr(2) = ( DCode(2) AND 255) * _
VoltFactor
If (DCode(1) AND 256) Then LowAmpCount(1) + = 1
If (DCode(2) AND 256) Then LowAmpCount(2) + = 1
If (DCode(1) AND 512) Then HighAmpCount(1) + = 1
If (DCode(2) AND 512) Then HighAmpCount(2) + = 1
If (DCode(1) AND 1024) Then LowFreqCount(1) + = 1
If (DCode(2) AND 1024) Then LowFreqCount(2) + = 1
If (DCode(1) AND 2048) Then LowFreqCount(1) + = 1
If (DCode(2) AND 2048) Then LowFreqCount(2) + = 1
If ResetCounts Then
LowAmpCount(1) = 0 : LowAmpCount(2) = 0
HighAmpCount(1) = 0 : HighAmpCount(2) = 0
LowFreqCount(1) = 0 : LowFreqCount(2) = 0
HighFreqCount(1) = 0 : HighFreqCount(2) = 0
ResetCounts = False
EndIf
CallTable dynamic
CallTable CalHist
CallTable slow
If TimeIntoInterval (0,1,Sec) Then
CDM_VW300Static (CPI_ADDR,StaticStrain(),Temp(),StrainStdDev()) 'Obtain un-shifted
'static strain.
'Calculate static digits reading (for troubleshooting)
StaticDigits(1) = StaticStrain(1)/GageFactor/NomBatchFactor
StaticDigits(2) = StaticStrain(2)/GageFactor/NomBatchFactor
'Now shift the given StaticStrain using the Offset/Baseline reading to obtain
'Final/adjusted StaticStrain.
StaticStrain(1) = StaticStrain(1) + StrainBL(1) : StaticStrain(2) = StaticStrain(2) + _
StrainBL(2)
'Calculate static frequency from static digits (for troubleshooting)
StaticFreq(1) = SQR(StaticDigits(1)*1000) : StaticFreq(2) = SQR(StaticDigits(2)*1000)
CallTable static
EndIf
NextScan
EndProg
G.1.11 50 Hz Measurement Example — One CDM-VW300, Two
Geokon 4000 Sensors with FieldCal()
'===Geokon4000-50Hz2Ch_4-25-13.CR3===
'CR3000 datalogger
'CDM-VW300 vibrating-wire analyzer
'Program to read 50-Hz dynamic data from one CDM-VW300 measuring two Geokon 4000 strain gages
'IMPORTANT -- Ensure that the CPI address coded on the following line matches the address
'reported for the attached analyzer in the DevConfig or DVWTool software.
Const CPI_ADDR = 1 '<<<<<<<<<<<<<
'Constants specific to the Geokon 4000 strain gages
Const GageFactor = 4.062 'G = 4.062 - Gage factor taken from sensor manual
Const NomBatchFactor = 0.97 'B=0.97 - Batch Factor taken from sensor calibration sheet
'Output will be in Strain, not Digits nor Frequency
Public Strain(2) : Units Strain() = Microstrain 'Measured strain output in units of Microstrain
Public StrainBL(2) : Units Strain() = Microstrain 'Baseline/offset strain reading in units of
'Microstrain (for calibration)
G-17