Monitoring waveforms from waveform generator at device under test

A method for determining a device under test (DUT) waveform, the method comprising:

• generating, from a signal generator in a single test and measurement instrument, an incident waveform (A) to be sent over a cable to a DUT;
• measuring, at a real-time waveform monitor (RTWM) circuit in the single test and measurement instrument, a propagation delay (t) of the cable caused by the cable as a signal propagates through the cable back to the RTWM circuit prior to connection of the signal generator to the DUT;
• the real-time waveform monitor (RTWM) circuit capturing a first waveform at a first test point between the signal generator and the DUT, the first waveform representing a combination of the incident waveform (A) and a reflection waveform (B);
• switching between the first test point and a second test point, the first test point and the second test point being within the RTWM circuit;
• the RTWM circuit capturing a second waveform at the second test point between the signal generator and the DUT;
• the RTWM circuit determining the reflection waveform (B) and the incident waveform (A) based on the first waveform and the second waveform;
• the RTWM circuit determining the DUT waveform based on the incident waveform (A), the reflection waveform (B), and the propagation delay (t), wherein the DUT waveform represents the incident waveform (A) generated by the signal generator as received by the DUT;
• and
• receiving user inputs as needed to adjust the signal generator to provide a desired waveform at the DUT.

A non-transitory computer readable storage medium having instructions stored thereon that, when executed by a processor of a single test and measurement instrument that includes a signal generator configured to output a signal to a device under test (DUT) through a cable, cause the single test and measurement instrument to:

• measure a propagation delay (t) of the cable caused by the cable as the signal propagates through the cable back to the single test and measurement instrument prior to connecting the signal generator to the DUT;
• capture a first waveform at a first test point in the single test and measurement instrument between the signal generator and the DUT, the first waveform representing a combination of an incident waveform (A) and a reflection waveform (B);
• capture a second waveform at a second test point in the single test and measurement instrument between the signal generator and the DUT;
• determine the reflection waveform (B) and the incident waveform (A) based on the first waveform and the second waveform;
• determine a DUT waveform based on the incident waveform (A), the reflection waveform (B), and the propagation delay (t), wherein the DUT waveform represents the incident waveform (A) generated by the signal generator as received by the DUT;
• and
• receiving user inputs as needed to adjust the signal generator to provide a desired waveform at the DUT.