private void tmrConvert_Tick(object eventSender, System.EventArgs eventArgs)
{
float EngUnits;
double HighResEngUnits;
MccDaq.ErrorInfo ULStat;
System.UInt16 DataValue;
System.UInt32 DataValue32;
int Chan;
int Options = 0;
tmrConvert.Stop();
// Collect the data by calling AIn member function of MccBoard object
// Parameters:
// Chan :the input channel number
// Range :the Range for the board.
// DataValue :the name for the value collected
// set input channel
bool ValidChan = int.TryParse(txtNumChan.Text, out Chan);
if (ValidChan)
{
if (Chan > HighChan)
{
Chan = HighChan;
}
txtNumChan.Text = Chan.ToString();
}
if (ADResolution > 16)
{
ULStat = DaqBoard.AIn32(Chan, Range, out DataValue32, Options);
// Convert raw data to Volts by calling ToEngUnits
// (member function of MccBoard class)
ULStat = DaqBoard.ToEngUnits32(Range, DataValue32, out HighResEngUnits);
lblShowData.Text = DataValue32.ToString(); // print the counts
lblShowVolts.Text = HighResEngUnits.ToString("F5") + " Volts"; // print the voltage
}
else
{
ULStat = DaqBoard.AIn(Chan, Range, out DataValue);
// Convert raw data to Volts by calling ToEngUnits
// (member function of MccBoard class)
ULStat = DaqBoard.ToEngUnits(Range, DataValue, out EngUnits);
lblShowData.Text = DataValue.ToString(); // print the counts
lblShowVolts.Text = EngUnits.ToString("F4") + " Volts"; // print the voltage
}
tmrConvert.Start();
}
private void cmdStart_Click(object eventSender, System.EventArgs eventArgs)
{
int i;
MccDaq.ErrorInfo ULStat;
MccDaq.Range Range;
MccDaq.ScanOptions Options;
int Rate;
int Count;
int Chan;
StrainConfig StrainConfiguration = StrainConfig.QuarterBridgeI;
double InitialVoltage = 0.0; //Bridge output voltage in the unloaded condition. This value is subtracted from any measurements before scaling equations are applied.
double VInitial = 0.0;
double OffsetAdjustmentFactor = 0.0;
double GainAdjustmentFactor = 0.0;
double Total = 0.0;
double VOffset = 0.0;
double RShunt = 100000; // Resistance of Shunt Resistor
double RGage = 350; // Gage Resistance
double VExcitation = 2.5; // Excitation voltage
double GageFactor = 2;
double PoissonRatio = 0;
double VActualBridge; // Actual bridge voltage
double REffective; // Effective resistance
double VSimulatedBridge; // Simulated bridge voltage
double MeasuredStrain;
double SimulatedStrain;
cmdStart.Enabled = false;
// Calculate the offset adjusment factor on a resting gage in software
// Collect the values by calling MccDaq.MccBoard.AInScan function
// Parameters:
// LowChan :the first channel of the scan
// HighChan :the last channel of the scan
// Count :the total number of A/D samples to collect
// Rate :sample rate
// Range :the range for the board
// MemHandle :Handle for Windows buffer to store data in
// Options :data collection options
Chan = int.Parse(txtChan.Text); // channel to acquire
if ((Chan > 3))
{
Chan = 3;
}
txtChan.Text = Chan.ToString();
VInitial = InitialVoltage / VExcitation;
Count = NumPoints; // total number of data points to collect
Rate = 1000; // per channel sampling rate ((samples per second) per channel)
// return scaled data
Options = MccDaq.ScanOptions.ScaleData;
Range = MccDaq.Range.NotUsed; // set the range
ULStat = DaqBoard.AInScan(Chan, Chan, Count, ref Rate, Range, MemHandle, Options);
// Transfer the data from the memory buffer set up by Windows to an array
ULStat = MccDaq.MccService.ScaledWinBufToArray(MemHandle, ADData, FirstPoint, Count);
for (i = 0; i < NumPoints; i++)
{
Total = Total + ADData [i];
}
VOffset = Total / Count;
VOffset = VOffset - VInitial;
OffsetAdjustmentFactor = CalculateStrain(StrainConfiguration, VOffset, GageFactor, PoissonRatio);
lblOffsetMeasStrain.Text = OffsetAdjustmentFactor.ToString("F9");
// Enable Shunt Calibration Circuit and Collect the values and
// Calculate the Actual Bridge Voltage
Options = MccDaq.ScanOptions.ScaleData | MccDaq.ScanOptions.ShuntCal;
ULStat = DaqBoard.AInScan(Chan, Chan, Count, ref Rate, Range, MemHandle, Options);
// Transfer the data from the memory buffer set up by Windows to an array
ULStat = MccDaq.MccService.ScaledWinBufToArray(MemHandle, ADData, FirstPoint, Count);
Total = 0.0;
for (i = 0; i < Count; i++)
{
Total = Total + ADData [i];
}
VActualBridge = Total / Count;
VActualBridge = VActualBridge - VInitial;
MeasuredStrain = CalculateStrain(StrainConfiguration, VActualBridge, GageFactor, PoissonRatio);
lblGainMeasStrain.Text = MeasuredStrain.ToString("F9");
// Calculate the Simulated Bridge Strain with a shunt resistor
REffective = (RGage * RShunt) / (RGage + RShunt);
VSimulatedBridge = (REffective / (REffective + RGage) - 0.5);
SimulatedStrain = CalculateStrain(StrainConfiguration, VSimulatedBridge, GageFactor, PoissonRatio);
lblGainSimStrain.Text = SimulatedStrain.ToString("F9");
GainAdjustmentFactor = SimulatedStrain / (MeasuredStrain - OffsetAdjustmentFactor);
lblGainAdjustmentFactor.Text = GainAdjustmentFactor.ToString("F9");
cmdStart.Enabled = true;
}