This application allows you to capture and analyze waveform data from an oscilloscope. You can visualize the data using various types of plots, including waveform and Bode plots.

The application assumes Channel 1 (Ch1) as the input and Channel 2 (Ch2) as the output on the oscilloscope. Based on this relationship, it calculates the transfer function G(s) = Vout/Vin, determining the frequency, gain, phase, and the complex number G(jω). This data is then plotted on Bode and Nyquist plots.

Typically, a sine wave is used to check the frequency response. The sine wave is generated using a function generator and injected into the input of the target circuit. The input is measured on Channel 1 (Ch1) of the oscilloscope, and the output of the target circuit is measured on Channel 2 (Ch2) of the oscilloscope.

The application sends commands to the oscilloscope to retrieve data. These commands are passive and do not alter any settings on the oscilloscope, ensuring that your oscilloscope's configuration remains unchanged.

Tested Devices

• TBS1000C series
• TBS2000B series
• InfiniiVision 2000 X series

Potentially compatible devices

• Tektronix oscilloscopes
• Keysight or Agilent oscilloscopes

Steps to Use

1. Connect: Click the Connect button to connect to your oscilloscope.
2. Capture Data: Once connected, click the Fetch waveforms from scope button to capture waveform data from the oscilloscope.
3. Auto Fetch: Enable the Auto Fetch Data checkbox to automatically capture data every 500 milliseconds. This interval can be adjusted based on the waveform length and rate.

Additional Features

• Save Data: Use each button to save Waveform data or Bode plot data.
• Load Data: Use the button to load Bode plot data. For demonstration purposes, you can use the Sample data.
• Copy to Clipboard: Use the button to copy Bode plot data to clipboard. This makes it easy to visualize the data in a spreadsheet.
• Toggle Visibility: Use the toggle buttons to show or hide specific charts like the Waveform, Lissajous Chart, Bode Plot, and Nyquist plot.
• Edit Data Points: Enable the Enable Delete Points checkbox to delete specific data points by clicking on them in the Bode plot and Nyquist plot. Use rectangular selection to delete multiple points.
• Trim Bode Plot: Click the Trim Bode Plot button to process and trim the current Bode plot data.
• Frequency Unit: Toggle between Hz and rad/s using the Change Frequency Unit button.
• TSV format: Use each buttons to save waveform data or Bode plot data in TSV format.

Tips

For improved frequency analysis, having more waveforms on the oscilloscope screen is generally advantageous, but too many can cause numerical instability. Adjust the horizontal range as needed based on the observed results. Similarly, if the amplitude is too low, accuracy may be compromised. Adjust the vertical range to ensure the waveforms are visible. Additionally, an excessively long record length on the oscilloscope can slow down data transfer, which may degrade the user experience. A record length of approximately 20k is suggested as a practical guideline.

LTspice support

Measured frequency characteristics can be imported and displayed in LTspice. By clicking on Generate LTspice subckt, you can download the subcircuit file named "bode_plot_data00x.sub." The following links contain the demo circuit "rc_circuits_fra.asc" and the component "FreqResLoader.asy" needed to use "bode_plot_data00x.sub." After downloading both, open the schematic in LTspice, change the value of the component (FreqResLoader) to "bode_plot_data00x," and run the simulation. This will enable you to compare the analytical results with the measured data.

rc_circuits_fra.asc FreqResLoader.asy

Disclaimer

This application was developed to improve the understanding of electrical engineering and control engineering. Although it aims to be highly reliable, we cannot guarantee that the application will not affect your devices. Please be aware of the risks and use it with caution.