Author Topic: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?  (Read 19942 times)

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Offline EEVblog

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Dave answers a forum question about whether the Rigol MSO1074Z mixed signal oscilloscope is worth double the price of the DS1054Z. Or whether it's better to buy the DSO and separate USB logic analyser.
But this applies to any mixed signal oscilloscope.

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Offline Howardlong

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #1 on: January 18, 2015, 09:02:46 pm »
Pretty much sums it up. I have two 4ch MSOs but don't use the LA capability very much, having four analogue channels is usually enough, as you rightly say so much is on serial busses these days.

When I was looking for a field scope though, I want to minimise the amount of kit I have with me, hence I bought an MSO1074Z-S, which has the two channel AWG too. Interestingly, I use its AWG function more than the scope. I've only used the LA function once for real work in the three months I've had it! And you're dead right, the screen gets cramped.

Couple of other things to note, the LA on the MSO1000Z is split into either 8 or 16 channels. With 8 channels, it deprives you of one of the analogue channels, and with 16 you're down to two.

Also, although not specific to the LA, the serial decode only decodes what's on the screen, and even then you need to have the timebase set fast enough for it to sample sufficiently to give results. At best you might only get 8 or 10 bytes of decode at any one time. This renders the event table feature useless.

But on the positive side, having all that stuff in one box for field use is handy, but I'd say not everyone has that requirement.
 

Offline EEVblog

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #2 on: January 18, 2015, 09:24:26 pm »
Couple of other things to note, the LA on the MSO1000Z is split into either 8 or 16 channels. With 8 channels, it deprives you of one of the analogue channels, and with 16 you're down to two.

Wow, didn't know that!
Kinda obvious though having shared memory for that, I didn't think of checking.
 

Offline EEVblog

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #3 on: January 18, 2015, 10:39:13 pm »
Given the subject I think this would have made a suitable EEVBlog video. It was too long (IMHO) for a blab and with a bit of actual bench work demonstrating the MSO in actual use it would have been ideal for EEVBlog video.

As mentioned, I don't have the Rigol MSO scope in question.

Quote
Also I was thinking given the recent review of the Digilent Analog Discovery  you might have been able to contrast it with a device like that. Particularly since you were targeting your advice towards the value conscious demographic.

That takes the video in much wider (and longer) direction.
I just wanted to answer one question.

Quote
Plus, I saw a few edits creeping in as it got longer.

If you followed me on twitter you'd know why there are edits.
 

Offline hamdi.tn

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #4 on: January 18, 2015, 10:58:49 pm »
that rigol is for 350$  :-+ crap country i live in , here a Chinese no name crap oscilloscope cost around 750$  :palm:
i just saw the review about that LA "analog discovery" 99$ ... 250$ when i saw it  :--
about the blab can't agree more ... most signals are bus signal and an oscilloscope can do the job , i can't see any good reason for investing money on LA if you don't really have the need to one.

 

Offline Bomber18

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #5 on: January 19, 2015, 12:15:07 am »
I saw similar advice for stand alone logic analyzers when I was researching this years ago and another plus of the two systems is separate failures and replacements if one becomes outdated.

Also just wanted to say how good the 1080p60fps videos look. Night and day difference, I can't believe other youtubers don't use that setting. Keep up the good work Dave!  :-+
 

Offline hikariuk

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #6 on: January 19, 2015, 12:18:54 am »
And here's me still trying to work out whether I should get the 50Mhz or 70Mhz version.
I write software.  I'd far rather be doing something else.
 

Offline EEVblog

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #7 on: January 19, 2015, 12:35:17 am »
Also just wanted to say how good the 1080p60fps videos look. Night and day difference, I can't believe other youtubers don't use that setting. Keep up the good work Dave!  :-+

Thanks.
I still need a lot more light. Considering a lighting upgrade specifically for that bench talking head shot.
 

Offline EEVblog

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #8 on: January 19, 2015, 12:36:09 am »
And here's me still trying to work out whether I should get the 50Mhz or 70Mhz version.

Get the 50Mhz.
70MHz doesn't offer much more for the price difference.
And it can be hacked if that's your thing.
 

Offline nowlan

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #9 on: January 19, 2015, 01:12:24 am »
Dave, when are you going to start shaming manufacturers to include basic serial decoders as standard in 2015?
Might run into trouble with only two probes, but rs232?
 

Offline alimirjamali

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #10 on: January 19, 2015, 02:06:23 am »
1st of all, thanks Dave for the whole 1000Z series comprehensive review/tear-down/trouble shooting saga ;D. I was waiting for this from the time he had a quick look at this scope in ^-^.

I would appreciate if Dave could share his thoughts on DS-1000z-S series (with Integrated Signal Generator). Is the AWG capable of recording from inputs and playing it? (Like the Agilent K-S 2000/3000 series) ::)

Is the extra $419 (comparing DS1054Z & DS1074Z-S) worth the 2 channel signal generator ????
 

Offline hikariuk

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #11 on: January 19, 2015, 02:48:53 am »
1st of all, thanks Dave for the whole 1000Z series comprehensive review/tear-down/trouble shooting saga ;D. I was waiting for this from the time he had a quick look at this scope in ^-^.

I would appreciate if Dave could share his thoughts on DS-1000z-S series (with Integrated Signal Generator). Is the AWG capable of recording from inputs and playing it? (Like the Agilent K-S 2000/3000 series) ::)

Is the extra  (comparing DS1054Z & DS1074Z-S) worth the 2 channel signal generator ????

You can get the DG1032Z for $680.  I've no idea what the functional improvement is with the dedicated unit though, although a cursory glance suggests you get more arbitrary waveforms and higher maximum output frequency.
I write software.  I'd far rather be doing something else.
 

Offline free_electron

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #12 on: January 19, 2015, 03:36:58 am »
One thing i missed in the blab or teardown /review (or i missed it) no mention of protocol triggering capabilites.

For examlle : trigger on a missing acq in i2c, or trigger on a write of a specific register in 82c , or a soecific address.


Here is an examlle. I have a dac driving an analog block. I want to measure the settling time.
At that point an mso is a must. You need not only time correlation but also bus activity trigger. Simple packet decoding is not enough the packet decoding needs ro be real time and filters need to be able to be set. I only want to trigger if a the dac is addressed. The scope should not trigger on any other device being addressed.

You dont need deep memory for that. You need realtime decoding of the packet and trigger launch.

Do the cheap machines even have such a thing ? The packet decoding is most likely done in post processing.

As comparison : the keysight 4000/5000/6000/7000 series have such trigger capability. Sont know about the 2000 or 3000.
Do the rigols ?
Even the old. 54622d has that. It can even do it on usb, can and a whole range of other busses.

I use that feature of the mso the most. Hook it up, set a filter on the transport , hide the digital channels and look at the analogs.

That is where the real strength of an MSO lies. The ability to trigger of a serial bus.
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Offline Howardlong

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #13 on: January 19, 2015, 03:51:11 am »
One thing i missed in the blab or teardown /review (or i missed it) no mention of protocol triggering capabilites.

For examlle : trigger on a missing acq in i2c, or trigger on a write of a specific register in 82c , or a soecific address.


Yes, it will do all those things, or at least they are there in the trigger menu. You can also select H/L/X in each bit position in address and data (up to five successive bytes after the address), and whether it's a read, write, or either.

I have only used the trigger on SPI so far, I am not yet convinced that it always triggered: I am not saying it doesn't work, it does, but I never went back to check if it really did consistently trigger. Happy for others to give further insight.
 

Offline moogli

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #14 on: January 19, 2015, 04:30:50 am »
Recently my old 70ies vintage Tek Scope died and thus, I had to get a new scope. The stuff that I want to measure with a scope often incorporate checking digital signals as well. So I also asked myself the same question: Does it make sense to get an Digital Oscilloscope plus - maybe later - an external logic analyzer or directly go for a mixed signal oscilloscope. In the end I did not really "decide it", because I had the occasion to get a used 2 analog channel Mixed Signal Oscilloscope at an affordable price, so I stopped thinking about it and went for that option. So far I'm happy with that solution. I guess, though, that I'll probably never really need all 16 digital channels. Speaking of my own projects, I don't see a situation where 16 individual channels really need to be exactly related in the time domain to debug something. And when it is about a digital parallel bus and really capturing transferred data (btw: playing around with an old Apple II  ;D ), 16 channels might be not enough (data and adress lines, Chip Select and Read/Write-Signals...).

One thing that interests me in terms of the "combination solution" (DSO with a LA): How good (or bad) is the jitter produced by the external trigger output of Oscilloscopes? It would be really interesting to feed the External Trigger output back into one analog channel of the same scope to evaluate the jitter and the fixed portion of the delay that this external output produces. How suitable is this trigger output really to get exact analog/digital time relations from the combination of those two instruments? It would be nice to see how different scopes "behave" in this regard, especially when they're triggering on irregular signals. Maybe thats an idea for a future episode of the EEV Blog? :-)
 

Offline moogli

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #15 on: January 19, 2015, 04:49:52 am »
Ok, just quickly tested this :-) With the MSOX3000, I get a super stable 30ns delay between the actual trigger and measured trigger out beeing fed back to the same scope. No visible jitter. But when not triggered (Auto mode), there is +/- 10ns jitter visible but of course this is not a really relevant finding. (Theoretically shouldn't happen, though...)
 

Offline V42bis

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #16 on: January 19, 2015, 06:27:30 am »
Be careful with the lower end Agilent mso's. I bought a msox2024 thinking I could look at i2c with he main 4 analog channels. That is locked out by agilent. Decoding must be done on the main analog channels. It's a stupid project managers attempt at differentiating ever model step.
 

Offline Dave Turner

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #17 on: January 19, 2015, 07:04:55 am »
Nearly 40 years ago, whilst developing my Z80 based system, I'd have thought I'd died and gone to heaven had I had an MDO.

Fortunately the Z80 used static memory so one could pulse the single phase clock manually. This allowed a simple 32 way latchable LED buffer circuit together with my second hand 2ch scope (which has long since departed to the junk yard in the sky - I can't even remember the make or model) to allow debugging.

I was taught eyes first, then think and be darn sure before actually doing. Now as then that's not bad advice. Of course sometimes there is no alternative to having the right piece of equipment.

The truth is 'worth the money' depends on your circumstances.
 

Offline tchicago

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #18 on: January 19, 2015, 09:17:33 am »
I have a general question about those PC-based USB logic analyzers.

Several years ago I was trying to use one of those inexpensive ones to reverse engineer some LCD display protocol. The analyzer was based on some Cypress USB chip + buffer. That attempt failed miserably because of the crosstalk between the non-shielded probe wires that connect the logic analyzer to my device under test. There were tons of false transitions shown on the traces that did not exist in reality, and that prevented me from using it at all.

What's the current state of affairs in this regard? Are there any inexpensive logic analyzers with the shielded coaxial probes? This is usually not listed in the specs, and it is hard to tell from the product photos.
 

Offline matkar

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #19 on: January 19, 2015, 10:09:13 am »
I personally wouldn't rely on getting a useful time correlation between Rigol DS1074Z output trigger and an external logic analyzer like Dave suggested in his video. The problem is in Rigol's trigger output.
I own a 1074Z for a year now and one of the ideas I had in the past was to connect 1074Z trigger output to 1052E trigger input and effectively get a 6 channel scope. DS1052E has an estimated stable delay of around 2ns on trigger input which is great. The problem is the trigger output on 1074Z which has around 70ns delay and quite a substantial jitter. Ok, I could compensate the 70ns (hopefully I remembered the nanoseconds correctly) delay but there's no way to get rid of the jitter.
Right now I don't know which firmware version (still the one it came with) I have on the scope, but I'll let you know if someone is going to pursue this issue.
I know Rigol had some jitter related issues not so long ago but don't know if the problems are related. I haven't updated my scope yet.
 

Offline scopeman

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #20 on: January 19, 2015, 10:22:04 am »
Hi Dave,

I am pretty much with you on this one (unless I have an MDO with 16 chan _ CLK+Qualifier+RF SA to 6GHz).

The USBee DX looks good especially for the serial decode. It seems that there are clones of these all over eBay.

However if you can quantify the trigger delay to trigger out you can use that to trigger a real Logic Analyzer like a HP1660 series or 16500  or similar which can be had really inexpensive on eBay. Often times these analyzers can be found with a complete set of pods and clips.

I found a 1660C complete with all of the pods and 132 clips at a local hamfest for 50.00. I bought a 1660AS with the scope option on ebay (no pods or clips) for 25.00 on ebay. I hope to get the time to see if  I can move the scope board into the C version to make it a CS. I am not sure I can do that but I am going to give it the old college try.

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Offline boffin

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #21 on: January 19, 2015, 12:17:17 pm »
Quote
Quote
Also I was thinking given the recent review of the Digilent Analog Discovery  you might have been able to contrast it with a device like that. Particularly since you were targeting your advice towards the value conscious demographic.

That takes the video in much wider (and longer) direction.
I just wanted to answer one question.
Given the Digilent is essentially a MSO, I would agree with this poster, if there was time to mention other standalone logic analyzers, 30 seconds mentioning the Digilent would have been appropriate. 

I just picked up a Digilent inexpensively ($100), and as I had neither a scope nor a LA, it was the perfect purchase for someone who only needs it on rare occasion.  What a difference from the scope I last owned (20 yrs ago) a Tek 2236 (which I paid $2200 for used).

As for the other poster who said "This is probably long enough to be a full EEVblog episode, and I agree.  The 15-20 min episodes are often quite useful; and I don't really think it's worth splitting the blabs out, they've been good watching so far.

keep up the good work Dave.
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Offline Bob S

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #22 on: January 19, 2015, 12:55:28 pm »
Time correlation can be a big factor. Just finished debugging a brushless DC motor drive with Hall feedback that had internment commutation and I cant imagine doing this with anything other than a MSO as 6 correlated channels was required. It comes down to what you are doing and the amount of time you have to do it.
 

Offline EEVblog

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #23 on: January 19, 2015, 12:58:40 pm »
Given the Digilent is essentially a MSO, I would agree with this poster, if there was time to mention other standalone logic analyzers, 30 seconds mentioning the Digilent would have been appropriate. 

Sure, but I honestly didn't give it a thought. I just grabbed a couple of dedicated logic analysers that were sitting together on my shelf to flash around on camera and pressed record.
I guess the Digilent  doesn't register with my subconscious as a go-to logic analyser.
But the whole point of the video was not to recommend a logic analyser, it was simply to answer the OP's question of whether or not to buy an MSO.
But you are of course right, the Digilent would have been appropriate as well.
 

Offline EEVblog

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #24 on: January 19, 2015, 01:05:00 pm »
As for the other poster who said "This is probably long enough to be a full EEVblog episode, and I agree.  The 15-20 min episodes are often quite useful; and I don't really think it's worth splitting the blabs out, they've been good watching so far.

The problem is one of a production difference between a blab video and a regular video. Blab videos are designed to be a zero thought, grab camera, press record, one take, upload.
They are designed to be quick and efficient, and expectations of them are low.
On the other hand once a decide to do a regular video, I go into regular video mode and start to think about stuff to include, experiments, demos, and extra tangent information that is appropriate etc. And a shoot it in an entirely different with dozens and dozens of different shorter clips.
It essentially takes all day to shoot and edit and muck around with even the simplest one of those.
And for a simple question like this I wanted to answer, if I decided to make it into a regular video it most likely wouldn't have because:
a) I didn't have enough time that day, and I hate shooting stuff over multiple days and avoid it wherever possible.
b) It would have screwed up my timeline because I would have to finish it today (Monday) so I probably would have done it in lieu of a Mailbag (yet again)

So I hope that gives some insight into how and why I shoot certain video. It was likely either a quick blab, or it was nothing.
 

Offline open loop

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #25 on: January 19, 2015, 07:39:43 pm »
Thanks Dave for the video  :-+

This is what I was asking myself exactly a couple of months ago and actually had a play with a couple of Rigol scopes at the Rigol vendor in my area. One was the MSO2000 series and the other was an MSO1074z. And I came to exactly the same conclusion that Dave did, if you really need the MSO capability then sure go spend the extra money. Otherwise use the extra few hundred $ to get a decent USB based LA.

One thing I did notice (as was pointed out to me) was that the LA probes of the MSO2000 were far better than the ones used on the MSO1074z. Not that the MSO1000z probes were bad as they are great for ocasional use.

I think that these days it is more important to have serial decoding and a JTAG tool to hand.
 

Offline alank2

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #26 on: January 20, 2015, 12:44:13 am »
There were tons of false transitions shown on the traces that did not exist in reality, and that prevented me from using it at all.
What's the current state of affairs in this regard? Are there any inexpensive logic analyzers with the shielded coaxial probes? This is usually not listed in the specs, and it is hard to tell from the product photos.

It can be a problem, one that can be mitigated by having a configurable threshold and also more grounds, best is one per channel.  Another technique might be to ground channels and use a signal channel every other channel.

Setting a proper threshold can eliminate a lot of noise.  LogicPort does this very well by having a variable threshold you can adjust.  Others like the Saleae allow you to set the threshold for the logic you are using such as 3.3 or 5, etc., but know that sometimes what they might give you for 5v is not a true 2.5v threshold, but something different.  This is where it is worth digging into the specifications a bit.

Having more grounds, hopefully one per signal near the signal is really ideal.  The newer Saleae's have a ground for each channel for example.

You can ground unused channels so they aren't floating and toggling which could eat up your buffer memory if compression is used.

Honestly this was a problem for me initially with LA's to the point where I questioned how useful they could actually be, but I found the issue was the cheap models I was using.  In the end I ended up with a Saleae Logic16 and also a Intronix LogicPort and have found that this isn't a problem on either one of these if I have it configured right.
 

Offline SteveyG

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #27 on: January 20, 2015, 12:47:35 am »
Thanks for taking the time to make a video on my question  :-+ It's an interesting discussion, which a lot of people will have a different opinion on. For me, the Rigol opens the question to potentially a different array of answers because of the price point - It's probably the only scope where you pay twice as much for the LA option. Buying the Keysight 2 or 3000 it's almost a no brainer to opt for the LA option.

The trigger output is something I'd not considered, so very useful tip!
« Last Edit: January 20, 2015, 12:55:44 am by SteveyG »
 

Offline alank2

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #28 on: January 20, 2015, 01:02:07 am »
I also think one more thing comes into this discussion and that is the way a scope is meant to trigger - over and over again on a repeating signal.  I found this not intuitive when it comes to trying to "analyze" logic signals.  Yes, you can set the scope to trigger once.  Yes, you can set the timebase to that everything you want to capture will end of up one screen.  Yes, with deep enough memory you can zoom into the places where you want to see what happened.

One thing that was mentioned with the Rigol's specifically is that it decodes what is on the screen - so if you scroll the screen in such a way as to push off the first few bits of some serial being decoded, it will decode wrong.  That is an issue that Rigol should fix especially given the price point they charge for their decoders.  I think they should decode from the beginning of the stream to the end and then let you scroll around without affecting the decoding...
 

Offline kevinpt

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Better triggering
« Reply #29 on: January 20, 2015, 05:06:29 am »
You missed that dedicated LAs have much better triggering options than the MSOs. The primitive pattern trigger in them is often not enough for capturing exactly what you need in a complex sequence.
 

Offline Howardlong

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #30 on: January 20, 2015, 07:04:32 am »
One thing i missed in the blab or teardown /review (or i missed it) no mention of protocol triggering capabilites.

For examlle : trigger on a missing acq in i2c, or trigger on a write of a specific register in 82c , or a soecific address.


Yes, it will do all those things, or at least they are there in the trigger menu. You can also select H/L/X in each bit position in address and data (up to five successive bytes after the address), and whether it's a read, write, or either.

I have only used the trigger on SPI so far, I am not yet convinced that it always triggered: I am not saying it doesn't work, it does, but I never went back to check if it really did consistently trigger. Happy for others to give further insight.

Here's a vid I did this afternoon doing I2C decoding and triggering. The triggering is perfect, the decoding not so much. (The test did decode perfectly on an Agilent 54831D).

Edit: Link here Doh!
« Last Edit: January 20, 2015, 07:14:22 am by Howardlong »
 

Offline Smokey

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #31 on: January 20, 2015, 01:21:49 pm »
With the MSO1074Z being double the price of the DS1054Z, how about buying two DS1054Z scopes and time correlating them.  That would give you at least 7 analog channels if you had to go trigger out of one to an analog channel in on the other.  Is there any software that could pull the traces off the scope and display them all on one screen on a PC?  I remeber seeing on another thread that on the Agilent gear you could take a dedicated scope and a dedicated logic analyzer and pull both time correlated data to display together on a PC.  It looks like Rigol software sucks, but that would be a killer stand alone app even.
 

Offline Bzzz

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #32 on: January 24, 2015, 11:04:07 am »
Get the 50Mhz.
70MHz doesn't offer much more for the price difference.
And it can be hacked if that's your thing.

Yep, we heard that. Still, I wonder why virtually nobody thinks of it as software piracy. I'm fine with the 100 MHz hack, as this is (afaik) not an upgrade offered by Rigol (yet). So in order to upgrade your DS1054Z to the DS1104Z the official way (including the sticker on the front), you have to sell the physical unit and buy the faster one.
But the triggering and memory stuff IS a paid option, just like upgrading from $knownOS from Starter to Ultimate Edition or whatever. Everything's already there, it just waits for you to put in the correct blargh and tadaa, additional functionality is activated. If you do that the official way you have to pay for it - if you use a keygen, it's free and you're a bad bad software pirate. Now back to Rigol, that sounds like a call to use keygens instead of buying an official upgrade...?
 

Offline hammy

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #33 on: January 24, 2015, 11:12:17 am »
Rigol products are sold since years with this possibility. Do you ever wondered why?  :palm:
 

Offline nctnico

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Re: Better triggering
« Reply #34 on: January 24, 2015, 11:31:16 am »
You missed that dedicated LAs have much better triggering options than the MSOs. The primitive pattern trigger in them is often not enough for capturing exactly what you need in a complex sequence.
OTOH MSOs often have much more memory than dedicated logic analysers (unless you have a really high end model). On an MSO you just capture everything and look at the data. That is usually quicker than setting up a complicated trigger condition. I'm not sure whether the Rigol 1000Z MSO is good value for money but spending a bit more on a proper MSO is money well spend if you are working with programmable logic.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Lightages

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #35 on: January 25, 2015, 07:20:21 am »
With the MSO1074Z being double the price of the DS1054Z, how about buying two DS1054Z scopes and time correlating them.

The way I understand it is that most things are serial protocols with usually no more than 2 to 4 signals lines to read and decode. If you need more channels, it could start getting up to 30 channels and much more if you are doing parallel buss analysis on things like micros and memory or DMA channels. So in this case even an 8 channel analyze and a 4 channel scope hooked together isn't going to do you much. Connecting 2 scopes together is not going to get you more than 7 channels. This is not that much more useful than 4 channels.

The other pain with trying to keep two instruments synced is the analysis after the capture. Sure the captures will correlated at the trigger point. When you try to scan along and look at the whole capture on both instruments you have two screens to look at, and the problem of trying to keep everything lined up the same way on both screens. This is only scratching the surface of the complication of trying to do the analysis after on two different screens. It can be done of course, but very tediously.
 

Offline nctnico

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #36 on: January 25, 2015, 07:59:32 am »
IMHO there is not much use for many digital channels. Nowadays everything on the outside is serial. If you have 8 digital channels on an oscilloscope (more will just clutter the screen) you can cover most of the logic analyses tasks. I do have an high end Tektronix logic analyser but the digital channels on my oscilloscope are just easier to work with.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Smokey

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #37 on: January 25, 2015, 08:50:49 am »
With the MSO1074Z being double the price of the DS1054Z, how about buying two DS1054Z scopes and time correlating them.

The way I understand it is that most things are serial protocols with usually no more than 2 to 4 signals lines to read and decode. If you need more channels, it could start getting up to 30 channels and much more if you are doing parallel buss analysis on things like micros and memory or DMA channels. So in this case even an 8 channel analyze and a 4 channel scope hooked together isn't going to do you much. Connecting 2 scopes together is not going to get you more than 7 channels. This is not that much more useful than 4 channels.

The other pain with trying to keep two instruments synced is the analysis after the capture. Sure the captures will correlated at the trigger point. When you try to scan along and look at the whole capture on both instruments you have two screens to look at, and the problem of trying to keep everything lined up the same way on both screens. This is only scratching the surface of the complication of trying to do the analysis after on two different screens. It can be done of course, but very tediously.
I was thinking more along the lines of sucking the data out of the scope and into a PC to do the analysis, rather than trying to line up two little scope screens.  But ya, that's one more step.

I also missed that there was no external reference clock input on these scopes.  No real time correlation :(  Gotta get into the thousands of dollars before you get a reference clock input.
 

Offline PioB

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #38 on: January 31, 2016, 09:18:36 pm »
One thing i missed in the blab or teardown /review (or i missed it) no mention of protocol triggering capabilites.

For examlle : trigger on a missing acq in i2c, or trigger on a write of a specific register in 82c , or a soecific address.
...
You dont need deep memory for that. You need realtime decoding of the packet and trigger launch.
...
As comparison : the keysight 4000/5000/6000/7000 series have such trigger capability. Sont know about the 2000 or 3000.
...

Did anyone get around to trying this out on a 3000? Or will one still end up also having to buy a USB LA after getting the highly recommended option on the scope for doing longer acquires?

...Buying the Keysight 2 or 3000 it's almost a no brainer to opt for the LA option.

What would the go to USB LAs be nowadays? The saleae pro (8/16 channels), the intronix logic port (34 channels), the dreamsourcelab dslogic (16 channels), the ikalogic scanaplus (9 channels), the digilent analog discovery 2 (16 channels plus 2 DSO, only 3.3 V iiuc) are all on my radar. But then again, ~1500 USD for the LA option on the scope AND an extra unit might be hard(er) to justify.

TL;DR: How useful is the LA option on the Keysight 3000 series and will one still be tempted to get a USB la for longer acquires?
 

Online blueskull

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #39 on: January 31, 2016, 09:23:25 pm »
No, not for me. Whenever I need to decode something it is usually some serial bus, so 4 channel is enough.

When I deal with parallel bus, it usually goes higher than 100MHz, which makes signal integrity a disaster, so I always end up with designing an adapter board and hook it up to an FPGA board.

So far, I've only used the MSO function on my Analog Discovery for a couple of times, and never used it on my MSOX3104A. So why I got a MSOX3104A instead of a DSOX3104A? Well, I got a deal that is even 50%+ cheaper than a new DSOX3104A.
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Offline Howardlong

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #40 on: January 31, 2016, 09:51:54 pm »
One thing i missed in the blab or teardown /review (or i missed it) no mention of protocol triggering capabilites.

For examlle : trigger on a missing acq in i2c, or trigger on a write of a specific register in 82c , or a soecific address.
...
You dont need deep memory for that. You need realtime decoding of the packet and trigger launch.
...
As comparison : the keysight 4000/5000/6000/7000 series have such trigger capability. Sont know about the 2000 or 3000.
...

Did anyone get around to trying this out on a 3000? Or will one still end up also having to buy a USB LA after getting the highly recommended option on the scope for doing longer acquires?

...Buying the Keysight 2 or 3000 it's almost a no brainer to opt for the LA option.

What would the go to USB LAs be nowadays? The saleae pro (8/16 channels), the intronix logic port (34 channels), the dreamsourcelab dslogic (16 channels), the ikalogic scanaplus (9 channels), the digilent analog discovery 2 (16 channels plus 2 DSO, only 3.3 V iiuc) are all on my radar. But then again, ~1500 USD for the LA option on the scope AND an extra unit might be hard(er) to justify.

TL;DR: How useful is the LA option on the Keysight 3000 series and will one still be tempted to get a USB la for longer acquires?

Yes, you can trigger on all those things on i2c on the x3000.

Regarding USB LAs, I used to use a LogicPort fairly regularly, but it largely sits in a drawer now as since getting an MSO I've found little need for it. Certainly the early saleaes and other USB LAs with low samplig rates I find to be of limited use: the LogicPort and the Saleae Pros sample at 500Msa/s which is far more useful although now in some circumstances it can be limiting.

The only reason I use the LogicPort now is for the occasional need to debug parallel busses like some LCD panels with controller chips, where 16 bits isn't enough, for everything else I use an MSO.

One exception to all of this is that when travelling, on the journey I use an Analog Discovery extensively for simple logistical reasons. Getting a scope out on your tray table with your laptop and DUT on a plane isn't going to work. On the other hand, if you've already plumbed in your breadboard to the AD and stuffed it all into a small cardboard box, you're good to go, no one will know any different. Just be prepared for more secondary screenings.
 

Offline rs20

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #41 on: January 31, 2016, 10:30:41 pm »
It's all well and good saying you can look at a serial bus with a 4 channel scope, but that leaves you very little extra to look at anything else you might want to correlate that SPI bus with.

For example, I recently was messing around with an ADXL345 chip with 4 SPI pins and two interrupts lines. Thus, the fact that I was working with a modern serial protocol didn't change the fact that I needed 6 channels. Just something for people to think about; I'm not sure staring at a serial bus in isolation is often the whole story?
 

Offline Howardlong

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #42 on: January 31, 2016, 11:18:56 pm »
If the proof of the pudding is in the eating, personally speaking I would almost always use the LA in an MSO rather than a USB based tool. Most of that is for the triggering capabilities which seem to be very basic on USB LAs. I am sure there will be other opinions though! The Saleae takes a slightly different workflow, in that it stores everything and you examine it after the capture. This is where a big monitor also comes in handy, but it's often not big enough! For an MSO, you tend to set up triggers.

I guess it's similar in software circles to using a log file instead of a debugger when comparing the Saleae way to how you'd use an MSO.
 

Offline System Error Message

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Re: eevBLAB #5 - Are Mixed Signal (MSO) Oscilloscopes Worth The Money?
« Reply #43 on: June 24, 2016, 12:44:05 am »
so what you're saying in the video is if you want a proper logic analyzer get 4 4channel scopes?
 


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