I'm using a Tektronix oscilloscope and I use only one channel. I export the data for that channel to a csv file and open it on my PC. I found the csv file actually contains data for two waveforms! One is called Glitch Capture Channel, the other is called Sample Channel. Then I plot out the waveform from these two sets of data. I found the waveform for the Glitch Capture Channel looks exactly the same with what I saw on the screen of the oscilloscope. While the waveform for the Sample channel looks very different. What are those two channels? What are the differences? When should I use which?
According to the manufacturer, the MSO2000 series detects glitches, which it defines as infrequent, high frequency transients. You have the option to filter out these transients via a feature called FilterVu, which acts as a low-pass filter.
Capturing the data yields both the filtered data (no glitches) and the unfiltered data (glitch waveform). Both are displayed on the screen, although they are actually two waveforms overlaid on one another. If the filter is set correctly, the Sample Channel should look like a smoothed, glitch-free version of the Glitch Capture Channel. If it looks drastically different, you may have the low-pass filter set too high, filtering out higher-frequency parts of your actual waveform.
I expect Tektronix would have covered this in whatever product literature ships with the oscilloscope, which you may not have if purchased second-hand.