From what I saw smaller/portable scopes do not have this useful feature. What would be a worrkaround for this when holdoff is not available? Could one use a larger timebase and then zoom in?
I love your delivery and pace. Quick and clear. I recently had a need to view an A.M. modulated signal and couldn't get the scope to trigger consistently. Someone suggested the holdoff and it worked like a charm. I guess I could have stopped it and examined the memory but I wanted to just view it in real time.
Thank you for the video. The explanation still confuses me. Your scope you have the delay at 0s. In the 2nd example, when it triggers at 0s, it's going to draw the rest of the waveform it captures, up until it the right of the display at t=2500us (500uS/div * 5div) -- regardless of any other edges cross the trigger. It's not like the scope will 're-trigger' a 2nd time mid-screen (a new user could misinterpret the explanation). Also, the scope has X Mbytes of memory so you can even scroll to the right if you want and see more of the waveform captured. So how does adding 800uS holdoff guarantee where the trigger starts the next arming?
You caught something that I didn't really want to explain because I thought it would be even more confusing and I wanted to keep this video short and sweet. So here goes with a detailed explanation. When you use trigger holdoff, it creates what's call "trigger qualified events". For the two examples I showed, a "trigger qualified events" occurs at the beginning of each burst. Another qualification for triggering is whether the scope is ready to trigger again. All scopes have dead-time when they are processing information/waveforms from the current and previous acquisition. The scope will not rearm its trigger circuitry until its fully ready to acquire another waveform. Now back to the "trigger qualified events". There can be lots of trigger qualified events happening, but if the scope in not ready to rearm its trigger, it will ignore those trigger qualified events. In both examples I showed, a trigger qualified event happens at the beginning of each burst. Once the scope rearms its trigger circuitry after the end of its dead-time/processing time, the scope will trigger on the next trigger qualified event. So, there are actually two qualifiers before the scope will trigger. 1. A trigger qualified event (the 1st edge of each burst). 2. The scope has rearmed its trigger circuitry and is ready to accept a trigger qualified event. This is basically an ANDed condition for triggering. Both conditions must occur. You mentioned a mid-screen event, as well as other events after mid-screen and possibly off-screen. These are all "trigger qualified events", but since the scope was still busy acquiring a waveform based on the trigger qualified event at center-screen, which was the actual trigger event, it ignored the second/mid-screen event (triggering hadn't been rearmed yet), as well as ignored other off-screen events to right. Now to something that is even more confusing that you didn't ask about. When you initially enter a holdoff time that should be valid for a repeating burst, the first, second, third, etc., triggers may not occur on the first edge of the burst. The scope may walk down the signal and trigger on seemingly random edges, but after few random triggers, it will eventually lock onto the first edge of each burst each time it triggers. This typically happens so fast that you don't see it. Or it could happen enough times during the scope's initial dead-time and that it's never observed Does this answer your question? Thanks for asking about this.
@@johnniehancock2426 "Short and sweet" is nice, but we want more, so just keep them as long as the subject is fully explaind. maybe make it two part in the same video, forst part, the sweet, and then just keep it running and explaind the rest is for the realy curius ones .. Good work anyway! 🙂
Can you not do it faster by just moving the knob of the trigger hold off until it stops? instead of using the cursors and then set the holdoff time manually.
This is way it was done on old analog scopes. But the setting was always relative to the time base range. So, setting the trigger holdoff between 0% and 100% of the sweep using the knob was pretty easy. But if you just start twisting the knob on one of today's digital oscilloscopes, you are likely to go right past a valid holdoff setting before the scope has a change to sync up. This would be especially true if the time gap between bursts is very narrow relative to the burst width. An alternative to using cursors would be to simply make a visual estimate and begin tweaking the knob within guesstimate range values.
