Difficulty when using oscilloscope to observe Ethernet signal

[houkensjtu]

Just browsing a service manual, I think TDS340 has Delayed Sweep capability.   Should do the trick.   Looks like a zoom tool in the Tek menus. but special:  Trigger, wait <x> amount of time, capture.

Yups, looks like the 340 has delayed time base. Tap the horizontal menu button, select "Time Base" from the soft key below the screen, then pick "Delayed Only" from the side menu. You'll then be able to dial in the delay from trigger event to capture.

I have given that a shot and everything works perfectly now!
It's proved again that I actually know NOTHING about my scope! THX!

[siggi]

I have given that a shot and everything works perfectly now!
It's proved again that I actually know NOTHING about my scope! THX!

Well, in fairness the UI on these TDS scopes can only be called "intuitive" for large negative values of "intuitive". I always have to hunt around for this on my TDS784D :/.

[tautech]

I have given that a shot and everything works perfectly now!
It's proved again that I actually know NOTHING about my scope! THX!

Well, in fairness the UI on these TDS scopes can only be called "intuitive" for large negative values of "intuitive". I always have to hunt around for this on my TDS784D :/.

Well done guys. 

Sounds similar to the Interval trigger setting I mentioned in reply #14.

[femtohertz15]

Nope    I've seen things called names like interval trigger, usualy gap more or less than a threshold of time between pulses.  Not the same! "delayed sweep" has been called that for more than 45 years at least.  It was the defining feature of a high performance lab CRO, much better if you had a 10-turn pot and the scope didn't have a fancy readout.  TDS's had it, HP54xxx have it.  It has gone out of fashion with deep memory scopes, if you don't have enough memory to span the the time delay you want, you're out of luck.  Which is sad, a coarse counter would be better than nothing.

[nctnico]

Nope    I've seen things called names like interval trigger, usualy gap more or less than a threshold of time between pulses.  Not the same! "delayed sweep" has been called that for more than 45 years at least.  It was the defining feature of a high performance lab CRO, much better if you had a 10-turn pot and the scope didn't have a fancy readout.  TDS's had it, HP54xxx have it.  It has gone out of fashion with deep memory scopes, if you don't have enough memory to span the the time delay you want, you're out of luck.

Not true. On DSOs you typically set the horizontal position but it may vary between brands.

[femtohertz15]

Sure, i haze a nice new rigol too.  You can shift horizontal and crank up time per division until you are out of sample ram for the desired time shift.  That is good, but it is zoom.  A delayed sweep (or acquisition maybe in modern terms?) lets you capture after a delay many times the length of sample memory at max sample rate.    The hardware counts off time during the programmed delay, bit doesnt waste sample memory until it is time.

[Performa01]

Sure, i haze a nice new rigol too.  You can shift horizontal and crank up time per division until you are out of sample ram for the desired time shift.  That is good, but it is zoom.  A delayed sweep (or acquisition maybe in modern terms?) lets you capture after a delay many times the length of sample memory at max sample rate.    The hardware counts off time during the programmed delay, bit doesnt waste sample memory until it is time.

I've yet to come across a DSO that would not do exactly that. Also 'Zoom' on a DSO with deep memory works exactly as it did on the analog scopes. Btw. my analog scope also has a 10-turn pot and a nice 3-digit digital readout for the delayed 2nd timebase

[Kilrah]

My old Philips PM3214 doesn't have the digits or anything digital at all, but has the 10-turn pot

Should take it out again one day.

[femtohertz15]

Love it!
Turn, turn, turn, click!
 

I have learned:  zoom wtf out to set up a large delay on a new digital,  rough the delay, zoom in.
Did work on rigol 100ms delay to 5ns/div.   

[houkensjtu]

I have updated the photo link with the wave form I captured by using "delayed time base". See the update information in my original post.