Products > Test Equipment

Most (Digital-)Scopes are freezing while vertical adjustement...

<< < (9/10) > >>

bdunham7:

--- Quote from: markone on November 15, 2022, 08:21:06 pm --- the last thing that is accepted in this sector is a DSO that freezes for a bunch of time during trace adjustments

--- End quote ---

Could you quantify "a bunch of time"?  I might agree with you if the bunch of time was long enough.

2N3055:

--- Quote from: markone on November 15, 2022, 08:21:06 pm ---I honestly think that the instrument cost factor must be taken in consideration in this kind of debate, otherwise the whole thing becomes pointless.

For instance, i spent the whole day using a customer's Rigol MSO5074, that almost freeze the whole screen update during trace vertical adjustment, but considering the cost paid (around 1000 euros, including PLA2216 digital probes kit) it was expected and tolerated but ... if it had been paid like 4-5K euros, well, there is no way to convince me that this level of "laggyness" could be acceptable.

I worked a lot with power electronics  (brushless motor control and induction heating), the last thing that is accepted in this sector is a DSO that freezes for a bunch of time during trace adjustments and considering that a 12bit DSO like new Rigol HDO series could be aimed to power electronics design lab, statemets like "no problem if DSO stops to update screen for a bunch of time" and / or "i do not give a s*** for analog emulation" make me laugh a lot.

if I bought a 5K euro scope like the HDO4804 to find out later the laggy behaviour shown in Dave's video, I would not be satisfied at all, especially in the belief that the employed HW can do much better.

--- End quote ---

Hardware doesn't exist in isolation. Scope is finely intertwined SW/HW. Maybe it cannot do better, because of architectural choices (in HW and SW) they made. Apparently optimizing this is not important for majority of users. As long as it is not 5-10 seconds, nobody cares..

Delay to restart might be visible but it won't kill anybody.
On Siglents I have here, it is a visible fraction of a second..  On Keysight 3000T it is less than 100ms. In practice either are good.

Would it be nice if every operation on every scope would be super fast and reaction instantaneous? Sure.
Is this a problem? No, it is not. It bothers you for some reason (which is fine by me) but it is no impediment to work.
You have all the right to be very particular with what you like or not, and you might even make (in this case emotional, I think) choices based on some details that are not really relevant to do the job. But you are only punishing yourself, because no scope manufacturer will make scopes that suits you, and you will have very limited and expensive choices.. What do you think, they are going to start crying because you said you don't like something?
Why do you want to buy HDO4000 ? 12 bit resolution? If I were you I wouldn't buy a product that is not finished yet. That would be more of a problem than this irrelevant waveform moving thing.
Do you need 12Bit resolution? If not, get yourself Keysight 3000T/G. That one is fast as you like it. You will get tons of other compromises with that choice though. And those might be important where it matters... Or not. You decide.

But, there is no perfect instrument.

bdunham7:

--- Quote from: 2N3055 on November 15, 2022, 09:27:28 pm ---On Siglents I have here, it is a visible fraction of a second.. 

--- End quote ---

I do have to wonder whether that might be done deliberately to give the front end time to settle down after an adjustment...  It does appear to take a bit (a very small bit) longer to get going after a position adjustment than it does from a scale adjustment.

2N3055:

--- Quote from: bdunham7 on November 15, 2022, 09:55:06 pm ---
--- Quote from: 2N3055 on November 15, 2022, 09:27:28 pm ---On Siglents I have here, it is a visible fraction of a second.. 

--- End quote ---

I do have to wonder whether that might be done deliberately to give the front end time to settle down after an adjustment...  It does appear to take a bit (a very small bit) longer to get going after a position adjustment than it does from a scale adjustment.

--- End quote ---

I don't have that information. But I know there are things scope has to sort out before continuing. Could it be done faster? I don't know.
It might be that voltage offset circuit needs time to settle to good DC accuracy.
People keep forgetting this is not moving signal plot on screen. Actual analog channel offset function has to offset signal with DC bias. It all has to settle down, otherwise first 10 or 100 triggers (depending on timebase) will have errors until it settles...
What scope does here is mixes in additional DC component, ADC samples that, and then program subtracts DC offset from absolute values and plots waveform in scaled values.

joeqsmith:

--- Quote from: 2N3055 on November 15, 2022, 05:17:17 pm ---1:  Immediately erases the screen and starts from left side again with changed vertical position.
or
2: Immediately stops the horizontal trace scan  and lets you move what was on the screen up and down. Once you stop, it resets and starts from the left.
or
3: It lets you move trace up and down while simultaneously keep scanning to the right like nothing is happening (except vertical movement, of course)

Thank you.

--- End quote ---

If you sweep at from 0.5 sec/div and slower my 80's LeCroy 7200 will erase the screen while adjusting, then start to fill the screen from the right to the left (roll mode).   At 0.2 and faster, the screen will display the last data set and return sweeping (left to right) once you stop adjusting.    With the LeCroy 64Xi, no matter if you use the roll mode or not, the screen will show the last data set.   If you display more than one trace, all traces will show the last data collected while adjusting and resume when you stop fiddling. 

I assume my Wavemaster behaves the same as the 64Xi, as they both use the same basic software.   

Of course, as you crank these scopes up, the time that they restart is much quicker.   So fast that you may not think they stopped but they have. 

Has any of this ever been a concern for me, nope.   It's obviously different than the old analog days.   Back then for digital storage, I designed and built a circuit that allowed me to capture the waveforms then play them back to the analog scope.   As shown, channel 1 (yellow) is the waveform and channel 2 is the trigger.  The circuit just keeps dumping the waveform and they trigger keeps it in sync.   You can scroll through the waveform using the delayed trigger output.   Because you may want to capture say a 10 second transient, and the analog scope is not going to have the persistence to show squat,  the box allows you to change the data rate to the scope.  So maybe you capture at 1Hz but you play back at 100kHz.   You can also change the gain and what not.  There was also a printer port but this only supports what ever dot matrix graphic printer I owned at that time.  There was however an RS232 port and I wrote some software for the PC to download and graph the data.  No doubt in assembler back then.   :palm:   The fun part with it is that it can output a fairly high voltage with a bit of current.  Enough to drive say a small motor or a transformer.   So, you could create some custom transient and dump it like an Arb but with a bit more power behind it.   Funny is the thing still turns on.  Its all wire wrapped. 

... Oh right, there was a point to this.  Because it was driving an analog scope, I always output the waveform  (to keep the display refreshed, again no persistence) no matter what you did with the interface.   I suppose back then, I was thinking things should work like the scopes of the time.

***
tried to clear up some of my mess...

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