Products > Test Equipment

Oscilloscope Zoom Out Quirk

<< < (3/113) > >>

JPortici:

--- Quote from: Wuerstchenhund on May 08, 2020, 08:12:56 am ---LeCroy scopes don't, and as Siglent follows LeCroy their scopes don't, either.

--- End quote ---

also Picoscope

nctnico:

--- Quote from: Wuerstchenhund on May 08, 2020, 12:35:36 pm ---
--- Quote from: EEVblog on May 08, 2020, 11:24:40 am ---
--- Quote from: Wuerstchenhund on May 08, 2020, 10:56:11 am ---So on a KS InfiniVision scope this only work in SINGLE or for the last acquisition in STOP mode as otherwise the scope will only capture enough for the period that's shown on the display. So it only works with a stopped acquisition.

--- End quote ---
Nope, it worked on both stopped and triggerd aquisitions.
--- End quote ---

It doesn't. Because all InfiniVision scopes only capture enough for the period displayed on screen and only use all the memory during the last acquisition when you press STOP (or on a single acquisition).

--- End quote ---
This depends on the version of InfiniVision scope you are using. The DSO7104A I used to own could record outside the screen in any mode. The newer models seem to only do this in single mode (if I interpret the user manual correctly).

2N3055:

--- Quote from: nctnico on May 08, 2020, 02:15:57 pm ---
--- Quote from: Wuerstchenhund on May 08, 2020, 12:35:36 pm ---
--- Quote from: EEVblog on May 08, 2020, 11:24:40 am ---
--- Quote from: Wuerstchenhund on May 08, 2020, 10:56:11 am ---So on a KS InfiniVision scope this only work in SINGLE or for the last acquisition in STOP mode as otherwise the scope will only capture enough for the period that's shown on the display. So it only works with a stopped acquisition.

--- End quote ---
Nope, it worked on both stopped and triggerd aquisitions.
--- End quote ---

It doesn't. Because all InfiniVision scopes only capture enough for the period displayed on screen and only use all the memory during the last acquisition when you press STOP (or on a single acquisition).

--- End quote ---
This depends on the version of InfiniVision scope you are using. The DSO7104A I used to own could record outside the screen in any mode. The newer models seem to only do this in single mode (if I interpret the user manual correctly).

--- End quote ---

You don't understand what Wuerstchenhund  is saying.

When running Infiniivision captures only "screeen lenght". If you change timebase , it will change what it captures, and again, will capture only  "screen length"every trigger.
But, if you press STOP, it will practically reconfigure engine for SINGLE mode ( with half of max mem) and will keep some data before first triggered frame, and will keep on capturing until it runs out of buffers.

So to you, it does look like it takes full mem, but it doesn't do that all the time but only on last capture when you stop.
When stopped it seems all the same to you, but Wuerstchenhund  is right, while running it's not.

How we know that? Well, if you put 3000T to 50 ns/div (500 ns per screen) it will retrigger at rate of 980 kHz. Slightly more than 1 us per trigger event.
Then you stop it and voila, you get 400us of capture. 40 us before trigger point, and 360us after trigger point.
And as you go from 50ns/div to 20us/div, it will keep sample rate of 5GS/s, while running keeps taking only what is "screen lenght" worth in every trigger, and if you stop it you get, again, you get 400us of data. Than sample rate goes down.

What does it mean? Well, when you're on 1ns/div, you get 40000x length worth of data than what is on your screen (10ns to 400us) if you stop it. If you are at 20us/div you get only 2x (200us to 400us).
And from that point on sample rate goes down, and game repeats, changing ratio "screen/stopped capture length" all the time. I guess table could be compiled. It's just I couldn't care less.
I'm not going to base my work based on side-effects of sample engine architecture..

P.S to be exactly technically correct it doesn't always capture exactly screen length. Sometimes it will capture a bit more, depending on division ratios of time/sample rate/buffer size chunks. But on every trigger event it captures only smaller sub buffer (compared to what it returns when stopped), minimum size to fit screen full of data necessary.

nctnico:
Again (4th time I'm explaining this): Keysight has changed the behaviour on the more modern models!

2N3055:

--- Quote from: nctnico on May 08, 2020, 04:54:23 pm ---Again (4th time I'm explaining this): Keysight has changed the behaviour on the more modern models!

--- End quote ---
Other people (other than you) started to think that 3000/4000 series behave the way you said. They don't.
Well, they do, sort of, but not in consistent and always useful way.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod