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| Keysight DSOS204A waveform update rate |
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| tautech:
--- Quote from: bdunham7 on June 10, 2022, 11:51:49 pm --- --- Quote from: nctnico on June 10, 2022, 11:44:28 pm ---You can greatly increase the chance of catching something by using a longer record. If you capture 1ms per acquisition, the dead time of the oscilloscope becomes much less significant. If something occurs every 10 seconds, then roll mode (continuous sampling) might even be better to catch something that stands out. --- End quote --- The test I'm using is a 10 MHz square wave with an additional pulse synced with the signal so that one in every 10 million, 100 million or 1 billion rising edges has a larger-then-normal overshoot. If the additional pulse is 10mHz--every 100 seconds--then it is one-in-a-billion. You can't use roll mode or 1ms/div for a 10MHz signal. You can put as many cycles on the screen as you can see clearly--but that is 10 to 20 at the most. You can try and I'm open to suggestions, but I don't know of a better method than what I'm doing for finding such a glitch. --- End quote --- Finding is just one thing, building a trigger for such rare events is another which is where a Zone trigger can be extremely useful. |
| nctnico:
--- Quote from: bdunham7 on June 10, 2022, 11:51:49 pm --- --- Quote from: nctnico on June 10, 2022, 11:44:28 pm ---You can greatly increase the chance of catching something by using a longer record. If you capture 1ms per acquisition, the dead time of the oscilloscope becomes much less significant. If something occurs every 10 seconds, then roll mode (continuous sampling) might even be better to catch something that stands out. --- End quote --- The test I'm using is a 10 MHz square wave with an additional pulse synced with the signal so that one in every 10 million, 100 million or 1 billion rising edges has a larger-then-normal overshoot. If the additional pulse is 10mHz--every 100 seconds--then it is one-in-a-billion. You can't use roll mode or 1ms/div for a 10MHz signal. You can put as many cycles on the screen as you can see clearly--but that is 10 to 20 at the most. You can try and I'm open to suggestions, but I don't know of a better method than what I'm doing for finding such a glitch. --- End quote --- Larger than normal overshoot shows up in roll-mode (with peak detect sampling) like a sore thumb. Look at the RTM3004 review I did a couple of years ago. Even with a trigger rate of 115Hz using a worst case scenario it can capture glitches (cycles with a different period) that happen 10 times per second quickly. |
| bdunham7:
--- Quote from: tautech on June 10, 2022, 11:55:39 pm ---Finding is just one thing, building a trigger for such rare events is another which is where a Zone trigger can be extremely useful. --- End quote --- Yes, first you find, then you trigger. The presumption of this test is that you can't trigger on it because you don't know what it is. My simple example is trivially easy to trigger on, but if my 'anomaly' were a slow rising edge, or example, it would be a bit more of a challenge. But as nice as the zone trigger is, I really haven't yet run into anything that was impossible without it. |
| free_electron:
--- Quote from: 2N3055 on June 10, 2022, 04:47:51 pm ---It is not exactly calculated that way.. It is statistical game, --- End quote --- that is why you need fast acquisition rate. if you can stream continuously without deadtime the chances of seeing it in persistence mode are 100%. if i can overlay every sample taken in one hour i will know if there are glitches or not. if i can only do one sample out of every 100... i have 1% chance of catching the glitch. if it can only grab 1 every thousand and then have random idle times between bursts ... i can't do the math but your chances are next to nothing. Sample fast , collect everything. First see if there are anomalies BEFORE you start fishing for them by doing data analysis. |
| tautech:
--- Quote from: bdunham7 on June 11, 2022, 12:42:38 am --- --- Quote from: tautech on June 10, 2022, 11:55:39 pm ---Finding is just one thing, building a trigger for such rare events is another which is where a Zone trigger can be extremely useful. --- End quote --- Yes, first you find, then you trigger. The presumption of this test is that you can't trigger on it because you don't know what it is. My simple example is trivially easy to trigger on, but if my 'anomaly' were a slow rising edge, or example, it would be a bit more of a challenge. But as nice as the zone trigger is, I really haven't yet run into anything that was impossible without it. --- End quote --- Likewise however with a zone trigger on a touch or mouse capable scope is quick to setup and a breeze to use. This zone is triggering on a signal from a STB3 that I later tweaked for nicer round numbers but initially setup with just a a mouse.....draw around the area of interest and kick it into life. Here the rising edge 0s trigger dominates and the set zone complements and we have a 2nd unused zone trigger if we need it. |
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