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Open topic with navigation CAPL Functions » VT System » SetImpedanceMode

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SetImpedanceMode

Valid for: CANoe DE • CANoe:lite DE Note
The function can only be called on system variable namespaces of appropriate channels of VT System modules. This function is only supported by the VT1004A variant and the VT1104 module.

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Method Syntax

Long SysVarNamespace.SetImpedanceMode (eVTSImpedanceMode Mode);

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Description

Switches for VT1004A/VT1104 between the mode with high impedance (default state) and low impedance. The behavior of a channel in mode with high impedance is the same as the behavior of a channel in older VT1004 modules. In the mode with lower impedance, the accurateness of the measurement of PWM frequency and duty cycle. This provides significant advantages especially for measurement of very low or high duty cycles. The input resistance is lower in this mode and thus the load on ECU output is higher. Details you find in the VT System Manual.

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Parameters

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Return Values

  • 0: Successful call
  • -1: Call error
  • -2: The namespace on which the command was called does not exist, is not a valid VT System namespace or does not support this command.
  • -3: The specified mode is not valid
  • -4: The function wasn’t called in the context of the main method of a test module. So it is not possible to wait until the setting will be taken over from the VT System. Otherwise, the call was successful but it is not sure if the settings have been taken over already when the call returns.
  • -6: The function is not supported by the used variant of the module.

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Example

PWM measurement with switching of the impedance mode.

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CAPL

double frequency;
double dutyCycle;

// Set PWM threshold to 12V
sysvar::VTS::LowBeamLeft.SetPWMThreshold(12);
// Set PWM measurement duration to 100ms
sysvar::VTS::LowBeamLeft.SetPWMMeasurementDuration(0.1);
// Enable low impedance mode to improve PWM measurement accuracy
sysvar::VTS::LowBeamLeft.SetImpedanceMode(eVTSImpedanceModeLow);

// Wait a bit until the PWM measurement has finished
testWaitForTimeout(200);

// Get measured values
frequency = @sysvar::VTS::LowBeamLeft::PWMFreq;
dutyCycle = @sysvar::VTS::LowBeamLeft::PWMDC;

// Check the frequency and duty cycle
if( frequency > 50 && dutyCycle > 20 )
{
    testStepPass();
}
else
{
    testStepFail();
}

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.NET (C#)

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VT System Control

  • Select LowBeamLeft
  • Set Sidebar | PWM Measurement | Threshold to 12.0
  • Set Sidebar | PWM Measurement | Meas. Duration to 0.1
  • Set Sidebar | General | Impedance to Low
  • Check measurement values ‘PWMFreq’ and ‘PWMDC’
vtsSetImpedanceMode