Sorry, another queston, roll mode this time...
Posted: 04 Jan 2012 00:25
Happy New Year! Having re read several times, and hopefully assimilated Neil's excellent reply in my overload protection thread, in this section, I have now got another question. In automotive diagnostics we are often measuring what I call very slow waveforms, often in the sub 800 Hz region, sometimes down to 8Hz. Viewing such slow waveforms and seeing any glitches is proving tricky, so a while ago I bought the Roll Mode upgrade from you. I have been paying with it using an old signal generator I have, giving a square wave signal at 2 to 600 Hz, and capturing various sets of data at different speeds via the roll mode. By means of roll mode it is much easier to see all of the waveform over extended periods. But what effect does running out of internal memory buffer at these low frequencies have on the stored signal? When the red line has crossed the screen I believe this shows the buffer is full? After that, what is occurring? is the buffer plain full, and stays full, and the rest of the data is caught in real time on the PC? Or is the buffer emptied very fast and it refills? I assume the former as no glitch is evident in the traces. What I am getting at is when the buffer is filled, at these low frequencies will roll mode continue to store accurate traces and be reliable for seeing glitches from missed or corrupted injection or spark events, for example? To what sort of frequencies will roll mode store useful data once the buffer is filled? Apologies if the questions are naive, but the more I learn unfortunately the more questions I seem to have. Thanks.