Usage

Select Variables

Right-click in the graph area on the Scope page and select Select Variables.

In the dialog that appears, drag variables from the left table and drop them into one of the tables on the right.

Real-Time Mode

On the Settings page, enable Real-Time Mode.

Go to the Scope page and click Start or press Ctrl+Space.

Verify that the status changes to Started and the frame rate is displayed.

Trigger Mode

On the Settings page, enable Trigger Mode. Right-click on a variable that will be used as the trigger and select Select as a Trigger.

Note: You can leave the trigger unselected; this configures free-running mode. Measurements will start immediately after clicking Start.

Configure the trigger:

• Sample Decimation – decimation factor for sampling.
• Trigger Slope – rising, falling, or alternating edge.
• One-Shot Mode – enable to stop after the first measurement.
• Trigger Threshold – the threshold at which the trigger fires.
• Pre-Trigger Samples / Post-Trigger Samples – number of samples captured before and after the trigger event.
• Trigger Prescaler – decimation factor for triggering events.
• Settling Time – delay after which the trigger starts being checked.

Go to the Scope page and click Start or press Ctrl+Space.

FRA (Frequency Response Analysis) Mode

On the Settings page, enable FRA Mode.

Configure the FRA on the Settings page:

• fmin, fmax: The frequency range limits.
• Nf: The number of frequencies within the frequency range.
• Frequency Distribution
  • h=1 Frequency Distribution: Measures a single period of the signal.
  • h=var Frequency Distribution: Measures the maximum number of signal periods, which is determined by the maximum number of samples (limited by the memory allocated on the MCU).
• A: The amplitude of the signal.
• Averaging: Vector or Exponential measurement averaging, applied when Nrepeat > 1.
• Nrepeat: The number of measurements to average per frequency.
• Type of Excitation
  • Single-Sine Excitation: Excites the dynamic system with a single-sine signal (one harmonic). It requires Nrepeat * Nf measurements.
  • Multi-Sine Excitation: Excites the dynamic system with a multi-sine signal (multiple harmonics). It requires Nrepeat measurements. Click Synthesize Excitation Signal after making any changes to the FRA configuration.

In your embedded project, get the excitation signal from the micro_dp_context() function and use it to excite the dynamic system:

float X, Y;

void timer_irq_handler(void)
{
    // Get the excitation signal.
    float excitation = micro_dp_context();

    // Example: measuring the open-loop transfer function while the loop is closed.
    float act = PI_Controller(e);
    Y = act;  // The second measured value (numerator).
    act += excitation;
    X = act;  // The first measured value (denominator).
}