System and method for variable sample rate signal acquisition

A method in test and measurement instrument, the method comprising:

• accepting a waveform having one or more waveform segments;
• sampling the waveform to produce a sampled signal, the sampled signal formed of a number of sample segments that each correspond to one of the one or more waveform segments;
• determining a slew rate of a present waveform segment;
• and
• storing the sampled segment corresponding to the present waveform segment in an acquisition memory only when the slew rate of the present waveform segment exceeds a slew rate threshold.

A test and measurement instrument, comprising:

• an input for accepting an input signal that varies in amplitude over time, the input signal formed of one or more waveform segments;
• and
• one or more processors configured to execute operations to cause the one or more processors to:
• sample the input signal to produce a sampled signal, the sampled signal formed of a number of sample segments that each correspond to one of the one or more waveform segments;
• determine a slew rate of a current waveform segment;
• and
• store the sampled segment corresponding to the current waveform segment in an acquisition memory only when the slew rate of the current waveform segment exceeds a slew rate threshold.