How to Set Up Oscilloscope Triggering (Part 1: Edge Triggering)

[Music] hi I'm Nikki Reynolds and this is another XY seas of oscilloscopes video in this video we'll be looking at how to use a trigger system to look at a stable waveform like previous videos we'll be using the Tektronix TBS 2102 oscilloscope and a function generator it's impossible to check the shape of a signal or take measurements with a waveform spooling all over the display it's a bit of a mess the trigger system lets you specify a point in your signal and captures it at that point this synchronizes the scope with your signal with the right trigger settings you can make repetitive waveforms appear stationary let's take a closer look at the front panel trigger controls you've already seen me use this control which controls the trigger level on this scope when I adjust the trigger level it shows up on the display to help me out with the setting the small T icon shows the trigger point since we're using the edge triggering the trigger point lines up with the intersection of input signal and trigger level I'll explain edge triggering in a minute but the part of the waveform before the trigger point is called the pre trigger data and the part after the trigger is called post trigger data in the last video I talked about a horizontal position which moves the waveform left to right notice how it moves the triggered point this button brings up the trigger menu which is where most of the setup occurs this scope has a few different types of triggers for this video I'm gonna use edge triggering it's a type you'll probably use most often with edge triggering and this is important the waveform is captured when the signal on this trigger source passes through a specific level on the rising or falling edge of the trigger source here's the source setting the slope setting and the level setting you can change the slope setting from rising to falling see how the trigger point moves from the rising to the falling signal this is a two channel scope and either channel can be used as a trigger source watch how the trigger changes from signal to signal when I change the source the AC power line can also be used to sync up the scope this is useful when you're working on power supplies are looking for power line noise in a circuit finally the right trigger source can be the key to analyzing complex signals for example it can be difficult to get a stable bit display on an AM signal like this one but if you can connect the modulating signal or envelope and use it as a trigger source it's easy to get a clearer picture in a previous video I talked about how input coupling changes the way the scope sees the input signal trigger sources can also have coupling and that coupling changes the way the scope sees the trigger signal for example in the real world you'll come across signals that are really noisy if you use a signal with noise as a trigger source and use the default direct coupling like I have here it'll end up with a drumbeat triggering I can choose hf reject option out of the coupling menu and the scope will filter out high frequency noise from the trigger source this gives me a stable perfectly triggered waveform you have other coupling options too you can reject low frequencies or you can use noise reject which makes the trigger system a bit less sensitive to eliminate the effects of noise there's just one more control to talk about trigger mode it's a good one to know Auto is the default trigger mode in this mode the cope waits for a trigger and it doesn't see one it captures and displays a waveform even if the trigger conditions aren't being met auto mode shows waveforms that aren't synchronized but it's really useful for setting up the trigger for signals that meet the trigger conditions pretty often auto mode will give you a stable trigger the other trigger mode is normal mode it's a little counterintuitive but more normal mode is not the default setting when the trigger system is in normal mode the scope acquires a waveform only when the trigger condition is met so as you can see when I lift it it's no longer triggering this mode is useful if you're looking for specific conditions that don't occur very often in some cases the trigger conditions can be very close to each other on the timescale to avoid multiple unwanted triggering you can use the hold off feature we'll talk more about the hold off feature in the next video now you know how to use an edge trigger to stabilize most waveforms if you watch our previous video on probe set up and scale settings you should be able to use your new skills on a real-world waveform in our next video we'll be talking about how to step things up a bit and using advanced trigger techniques to capture digital signals and worse find out more at vikon's website you

Channel: Vicom New Zealand

Views: 3,506

Rating: 4.9344263 out of 5

Keywords: XYZ's of oscilloscopes, How to use oscilloscopes, Oscilloscope triggering, TBS2000

Id: Q10j6yUxAik

Length: 6min 5sec (365 seconds)

Published: Thu Jan 24 2019