Campbell Scientific CDM-VW300 Series Dynamic Vibrating-Wire Analyzer System - Manual (Page 110)

Appendix G. CRBasic Program Library
Public DCode(2) As Long 'Dynamic diagnostic code
Public StaticStrain(2) : Units StaticStrain() = Microstrain 'Static (1Hz) strain reading in
'microstrain
Public StaticDigits(2) 'Calculated Static (1Hz) Digits output (for troubleshooting).
Public StaticFreq(2) : Units StaticFreq) = Hz 'Calculated Frequency (1Hz) from static digits
'(for troubleshooting)
Public Temp(2) : Units Temp() = DegC ' Temperature in DegC
Public TempBL(2) : Units TempBL() = DegC ' Temperature Baseline in DegC
Public StrainStdDev(2) : Units StrainStdDev() = Microstrain 'StdDev of dynamic strain readings
Public ZeroMode 'Mode variable for baseline/offset zeroing calibration
'Configure the CDM-VW300 device
Dim Enable(2) As Long = { 1, 1}
Dim Max_AMP(2) = { 0.002, 0.002}
Dim F_Low(2) = { 300, 300}
Dim F_High(2) = { 6000, 6000}
'Use Hz^2 (1) instead of Hz (0) so we can get to digits
Dim OutForm(2) As Long = { 1, 1}
'Use a multiplier of 0.001 to divide by 1000 and get digits. Then scale further to get to Strain
Dim Mult(2) = { 0.001*GageFactor*NomBatchFactor,
0.001*GageFactor*NomBatchFactor} 'Digits (Hz^2/1000) times G times B results in strain
Dim Off(2) = { 0.0, 0.0}
'Use Steinhart-Hart coefficients to get thermistor output in DegC
Dim SteinA(2) = {1.4051E-3, 1.4051E-3}
Dim SteinB(2) = { 2.369E-4, 2.369E-4}
Dim SteinC(2) = { 1.019E-7, 1.019E-7}
Dim RFMB(2) As Long = { 20, 20}
Dim RFAB(2) As Long = { 20, 20}
Dim RFLL(2) = { 400.0, 400.0}
Dim RFHL(2) = {4000.0,4000.0}
Dim RFHY(2) = { 0.005, 0.005}
Dim RFOF(2) As Long = { 100, 100}
CDM_VW300Config (0,CPI_ADDR,0,Enable(),Max_AMP(),F_Low(),F_High(), _
OutForm(),Mult(),Off(), SteinA(),SteinB(),SteinC(), _
RFMB(),RFAB(),RFLL(),RFHL(),RFHY(),RFOF())
DataTable (static,true,-1)
Sample (2,StaticStrain(),IEEE4)
Sample (2,Temp(),IEEE4)
Sample (2,StrainStdDev(),IEEE4)
EndTable
DataTable (dynamic,true,-1)
Sample (2,Strain(),IEEE4)
Sample (2,DCode(),IEEE4)
EndTable
DataTable(CalHist,NewFieldCal,-1)
SampleFieldCal
EndTable
BeginProg
'50 Hz/20msec scan rate
Scan (20,msec,500,0)
CDM_VW300Dynamic (CPI_ADDR,Strain(),DCode()) 'Get unshifted strain
'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)
CallTable dynamic
CallTable CalHist
If TimeIntoInterval (0,1,Sec) Then
CDM_VW300Static (CPI_ADDR,StaticStrain(),Temp(),StrainStdDev()) 'Obtain un-shifted static
'strain
G-18