Author Topic: new killer scope in town - a true game changer from R&S - RTB2002 & RTB2004  (Read 490589 times)

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Online maginnovision

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I think that is exactly what the scope should do. If there are multiple triggers within one frame-time of the screen it should show all the events within this time, no? I thought that is what intensity grading is based on. So if you have two qualified trigger events within 16ms (assuming 60Hz LCD refresh rate; I know this is simplified ) then I would like to see both, no? Or should one just be thrown away? Do i miss something?
The problem is that with 2 signals on screen you have no clue what is being decoded so yes, that is a problem.

Seems like the answer then is triggering on what you want to see rather than randomly triggering on edges to see data or performing single shot captures rather than forcing trigger while it's sampling normally.
 

Offline mtdoc

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PEBKAC (or more accurately PEBOAK) error perhaps?
 
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Online 2N3055

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I think that is exactly what the scope should do. If there are multiple triggers within one frame-time of the screen it should show all the events within this time, no? I thought that is what intensity grading is based on. So if you have two qualified trigger events within 16ms (assuming 60Hz LCD refresh rate; I know this is simplified ) then I would like to see both, no? Or should one just be thrown away? Do i miss something?

Michael


Seems like the answer then is triggering on what you want to see rather than randomly triggering on edges to see data or performing single shot captures rather than forcing trigger while it's sampling normally.

I understand now what are you saying, and no, it doesn't work that way. You have a trigger, then scope disables triggering, it scans full screen to the end, rearms trigger,  and waits for new trigger condition.
There cannot be several trigger events on same screen scan. Signal cannot be two different signals at the same time. You can have only one signal value at any given point in time.

If you have a fast scope and fast triggers and persistence on screen (simulating phosphorus), you will see multiple waveforms on  the same screen, but because of eye or screen persistence, not because those events happened at the same time. It only looks to you they did. They happened sequentially. With sometimes quite long pauses in between. Hence waveforms (screen, buffers) per second metrics on the scopes.

You cannot have another trigger while scanning on first trigger. It negates point of oscilloscope being oscilloscope, device that shows voltage variation in time domain.
And on digital scope you have last waveform that happened in the buffer to see.
If you want to capture number of separate captures and keep them all, you need to have a scope with segmented memory and switch it on.
But they will be kept separately, and you can look at them (and decode them) separately. On some scopes you can chose to overlap all recorded segments and see them at the same time, but that is not normal scope view, but a special analysis mode.
 

Online tautech

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There cannot be several trigger events on same screen scan.
:bullshit:
A DSO triggers on and displays the first trigger event/condition and any that might also fit on the display.
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Online nctnico

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I think that is exactly what the scope should do. If there are multiple triggers within one frame-time of the screen it should show all the events within this time, no? I thought that is what intensity grading is based on. So if you have two qualified trigger events within 16ms (assuming 60Hz LCD refresh rate; I know this is simplified ) then I would like to see both, no? Or should one just be thrown away? Do i miss something?

Michael


Seems like the answer then is triggering on what you want to see rather than randomly triggering on edges to see data or performing single shot captures rather than forcing trigger while it's sampling normally.

I understand now what are you saying, and no, it doesn't work that way. You have a trigger, then scope disables triggering, it scans full screen to the end, rearms trigger,  and waits for new trigger condition.
There cannot be several trigger events on same screen scan. Signal cannot be two different signals at the same time. You can have only one signal value at any given point in time.
That isn't true at all. A DSO which can do several thousands of waveforms/s has to stack multiple waveforms into one screen refresh cycle (usually 60Hz). This has been explained on this forum many many times already.
Normally this isn't a problem (and depending on the persistence setting wanted behaviour) but when using protocol decoding it is making it hard or even impossible to see which signal is being used for decoding.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online tautech

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I think that is exactly what the scope should do. If there are multiple triggers within one frame-time of the screen it should show all the events within this time, no? I thought that is what intensity grading is based on. So if you have two qualified trigger events within 16ms (assuming 60Hz LCD refresh rate; I know this is simplified ) then I would like to see both, no? Or should one just be thrown away? Do i miss something?

Michael
No, it's operator error.
Rich explained what needs be done except I think he missed one thing, a falling edge or protocol trigger is best suited for protocols.
« Last Edit: June 21, 2018, 10:15:23 pm by tautech »
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Online 2N3055

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That isn't true at all. A DSO which can do several thousands of waveforms/s has to stack multiple waveforms into one screen refresh cycle (usually 60Hz). This has been explained on this forum many many times already.
Normally this isn't a problem (and depending on the persistence setting wanted behaviour) but when using protocol decoding it is making it hard or even impossible to see which signal is being used for decoding.

You don't understand. I'm not talking how scope writes and combines those individual scans to a screen buffer. 
Also I'm not talking about fact that digital trigger DSO sample in circular buffer and start copying data in output buffer after trigger.... It's not really waiting for buffer, but rather not caring for sampled data until trigger happens.
All of those combined waveforms that go into screen buffer were combined from consecutive, single trigger events of fixed length... Scope cannot be retriggerable in the middle of the one post trigger sample buffer length.
 

Offline Octane

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I should clarify: with one screen time I don’t mean the time it takes the “beam” to go from left to right. I meant the refresh-rate of the display. So of course if your timebase is 10us and you have 10 horizontal divisions then the trigger will be disabled for at least 100us (if we assume no pre-trigger). But after those 100us it can trigger again. So if we refresh the display let’s say 10 times a second, we have 100ms of time to capture, in the best case, 1000 waveforms. And all of those can be shown (intensity graded) on the screen. If the waveform has two different pulsewidth (and you trigger on the rising edge you will see two falling edges on the screen. If you don’t use a more complex trigger, you can’t get around that (except maybe a long trigger hold-off).

P.S.: I know that the numbers may not be fully realistic, I took those just to make a point.

Michael
 

Online exe

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To me it looks more like a usability issue. E.g., what feature means to user, it useful, does it create confusion (or how intuitive the behavior), is it possible to change it, etc.

I mean, it's not (just) about technical justification.

PS to me it looks strange without intensity grade. Disclaimer: I'm not an owner of this scope. May be this is easy to fix in display setup, I don't know.
 

Offline mikeselectricstuff

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I should clarify: with one screen time I don’t mean the time it takes the “beam” to go from left to right. I meant the refresh-rate of the display. So of course if your timebase is 10us and you have 10 horizontal divisions then the trigger will be disabled for at least 100us (if we assume no pre-trigger). But after those 100us it can trigger again. So if we refresh the display let’s say 10 times a second, we have 100ms of time to capture, in the best case, 1000 waveforms. And all of those can be shown (intensity graded) on the screen. If the waveform has two different pulsewidth (and you trigger on the rising edge you will see two falling edges on the screen. If you don’t use a more complex trigger, you can’t get around that (except maybe a long trigger hold-off).

P.S.: I know that the numbers may not be fully realistic, I took those just to make a point.

Michael
That's exactly what Trigger holdoff is for. Or a longer timebase and zoom mode
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Offline Octane

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That’s why I mentioned it ...  :D
 

Offline KaneTW

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I'm probably about to pull the trigger on either

a RTB2K-COM4, and have a good 300MHz scope with everything that I need (~3.8k EUR w/o VAT)
a RTB2K-74M and see if I can hack it (~1.8k EUR w/o VAT)
a MSOX2024A with a bunch of options, used, from keysight's ebay, for 2.2k$

Any comments or alternatives I haven't considered?
« Last Edit: June 23, 2018, 01:12:43 am by KaneTW »
 

Online nctnico

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I'm probably about to pull the trigger on either

a RTB2K-COM4, and have a good 300MHz scope with everything that I need (~3.8k EUR w/o VAT)
a RTB2K-74M and see if I can hack it (~1.8k EUR w/o VAT)
a MSOX2024A with a bunch of options, used, from keysight's ebay, for 2.2k$

Any comments or alternatives I haven't considered?
GW Instek MSO2204E . Price wise between all of them and it does give you deep memory and protocol decoding. I wouldn't consider the MSOX2024A because the memory is too small.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online 2N3055

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GW Instek MSO2204E . Price wise between all of them and it does give you deep memory and protocol decoding. I wouldn't consider the MSOX2024A because the memory is too small.

Agree  with Ntnico,  Keysight 2000 series are a joke for what they cost.
Especially used and with no or limited warranty for 2.2k$. I reality, they are worth more like 800€, and that mostly on brand recognition..
GW Instek MSO2204E outperforms it in every way.
Where do you plan to get RTB2K-COM4 from for 3.8k€ ? List price is 5.5k€ !!
If you can get it for that price I would either go with RTB2K-COM4 if you can afford it , or if you would want pay less I would go with GW Instek MSO2204E.
 

Offline KaneTW

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Thanks for the pointers. Keysight hasn't been too attractive especially because of low memory and no warranty.

Education (student) discount from Datatec is ~30% for the -COM4, and I get the VAT back.

I'll look into the MSO2204E. Seems like a good option. -COM4 is still super attractive but also quite a bit steeper in price.
 

Offline KaneTW

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Paid for my RTB2K-COM4. It should arrive sometimes next week.
 

Offline hwj-d

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But prepare yourself already.
With me, relatively quickly the desire came, to have to equip it with the RTB-PK1 option bundle, then with the RTB-B1 MSO option too.  :scared:
 

Offline KaneTW

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It's fully optioned, so that desire is cut off at the root.
 

Offline hwj-d

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Lucky guy   ;)
 

Online rhb

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Thanks for the pointers. Keysight hasn't been too attractive especially because of low memory and no warranty.

Education (student) discount from Datatec is ~30% for the -COM4, and I get the VAT back.

I'll look into the MSO2204E. Seems like a good option. -COM4 is still super attractive but also quite a bit steeper in price.

Who is "Datatec"?   I didn't find anything sensible with google.
 

Offline KaneTW

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http://datatec.de/, a German test & measurement distributor
 

Offline glowman

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Aside from the bugs pointed out from others I have found some myself.  I find this new version 2.101 to be so buggy.  I really hope that R&S development team will put more effort in the firmware.  The reason I bought a German branded scope is primarily for stability when it comes to firmware.  Bells and whistles is  just secondary to me (big touch screen, 10-bit, etc.)  Or else, it would not be so much different to China made scopes which is so much cheaper.  I understand that regardless what brand it is and the device is relatively new, there will be bugs to fix but, I'm expecting it to be harder to find on a brand like R&S.

Ok -on with the bug:
Under Pattern Gen, pattern, when you select Audio -I2S, the menu will exit. Then you can't get back into pattern gen menu again.  The output has a 9600hz square wave at P0.  Problem still remain even after restarting the scope.  To be able to get back in, just press preset.  Frankly I don't know what to expect with "Audio -I2S, Audio- TDM" but, not being able to get back in is obviously a bug.

Another bug is on the new zoom function.  When you press the zoom, the rectangle's vertical extremes are "sometimes" way up or way down to the point that there is nothing displayed below.  pushing and turning the knobs does not help.  Most of the time, the zoom works as it should and sometimes it's acting up.  As an analogy, it seems like while it's displaying new york, it's zooming in mexico.

Just today while checking the firmware page, the new firmware 2.101 is gone and what's there is the one released last Nov. 2017.  What happened?  Did I miss something?

FYI.
 

Offline kaz911

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Just today while checking the firmware page, the new firmware 2.101 is gone and what's there is the one released last Nov. 2017.  What happened?  Did I miss something?



yes new firmware gone? V2.0.0 is the newest again.

https://www.rohde-schwarz.com/firmware/rtb2000/

Hope it is nothing too serious but I can' t find any mentions on why it has been removed.
 

Offline Ghislain

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It is still available on the US site: https://www.rohde-schwarz.com/us/firmware/rtb2004/#
 

Offline KaneTW

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It's not. Firmware version 02.000.
 


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