Can I use the external trigger to simultaneous capture waveforms on two oscilloscopes?

Question

I want to look at synchronization in a 6 oscillator network (oscillators are about 100 kHz, 1.5 V_pp, if this matters). I have a 4 channel oscilloscope (Tektronix TDS 2024B) and a 2 channel oscilloscope (Tektronix TDS 1001B). Can I use a signal generator as an input to the External Trigger of both oscilloscopes so that I can perform a screen capture at the same time on both scopes? I was imagining that I could input a triangle wave and capture at the peak, or something like this.

I am just learning electronics (chemical engineer/applied mathematics background), so if the answer is yes, please keep in mind that my curiosity is great but my knowledge is shallow.

Answer 1

From this document: "Most Tektronix oscilloscopes also provide a discrete output that delivers the trigger signal to another instrument—a counter, signal source, or the like."

It's probably on the back of the scope, and you may need to read the manual to get it working right.

If you were operating at 100MHz I'd also caution you that there's probably some timing skew -- but unless the oscillators have much sharper rise times than their frequencies and you're comparing nanoseconds of difference, then you're probably OK. If you do need to resolve things that fine, get everything working and swap inputs between the two scopes to see how much they change timing. Ideally you'll be able to calibrate for any timing offsets.

Answer 2

Yeah, these are super low end scopes and as a result have the bare minimum of features. Looks like they both have ext trig inputs, but no trigger output. If you can get away with 5 inputs instead of 6, then what you can do is trigger both scopes on the same input signal. If you really need all 6 inputs, then you might need to get a bit creative. It might be possible to connect a signal to a channel input on one scope and the ext trig input on the other scope so you can trigger both on the same signal but only display it on one. You'll have to check the manual to see what the ext trig input is capable of and if it has a normal 1 Meg input impedance. If it has a 1 M input impedance, then you can just put a scope probe on it. If it doesn't, then you will need to get a bit more creative.

Answer 3

Here is the solution I implemented (and I welcome refinements, but this solution seems to work for the time being).

I use a signal generator to input a signal into the external ports of both oscilloscopes. I put the oscilloscopes into "acquire" mode, and tell them to trigger off the rising of the external input after I press the "single seq" button. Because I made the signal generator about 1/2 Hz, I can push the buttons simultaneously enough to be reasonably sure that both scopes are capturing from the same event. I measured an oscillator in both scopes to be sure, and yes, it works.

Thanks for the useful feedback; when I asked the company rep, I was able to ask better questions based on your responses, which led me to this solution.