Campbell Scientific CDM-VW300 Series Dynamic Vibrating-Wire Analyzer System - Manual (Page 113)

Appendix G. CRBasic Program Library
G.1.13 50 Hz Measurement Example — One CDM-VW300, Two
Geokon 4000 Sensors with FieldCal() and TableFile() to
CF
'===Geokon4000-50Hz2ChEventTableFile_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.
'Write data to CF card at each event.
'Demonstrate use of TableFile() with Option 64, DataEvent(), and DataInterval() to conserve
' data
storage.
'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 calibration sheet provided with
' sensors
'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)
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
Public NewDynFileStored As Boolean 'Needed for TableFile
Public NewStaticFileStored As Boolean 'True when a new file was just created on the card
Public LastDynFileName As String * 35 'The name of the new file just created on the card
Public LastStaticFileName As String * 35
'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)
'Even though data is observed once per second,
'write out 1 minute averages
G-21