Author Topic: Rigol Ds1074z I2C Decode event table only shows one packet.  (Read 14875 times)

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Offline Mark_O

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #25 on: August 05, 2014, 12:44:18 pm »
In the thread above there is an indication that there are many differences between DS1074Z and DS2072A in terms of features.

But these differences are caused by the software.

Strictly speaking, the DS1074Z should be able to do everything that the DS2072A can do, just less B/W and sample rate.

In the current SW implementation there is much differences, but for me it is hard to believe that Rigol would not be able to make all DS2072A features available in the DS1074Z.

The HW in the DS1074Z is good enough to support all of the DS2072A features!
In fact it even has 4 analog channels. If they would just make the software feature complete, this would be the best scope out there if you don't need more than 100 MHZ B/W.
You are making some sweeping statements/assumptions here.  :o

Yes, no kidding.  Along with a whole lot of wishful thinking.

Quote
Be ready for all the replies to the contrary.  :box:

Well, I'm not sure it's worth the trouble.  Apparently, he has no concept of product differentiation, and that a manufacturer may have valid reasons NOT to make the feature sets identical.  Regardless of how hard that is for him to believe.  Or the fact that while they are similar, they don't have exactly the same hardware, and thus may be more limited in capabilities.

What he should be saying is "I don't understand", because he doesn't.  Or that he finds it disappointing.  That's certainly a valid sentiment, that many of us could get behind.  Instead he's making proclamations of how he thinks things should be, because that would be his preference.  He started out by claiming they were the same, then when corrected, shifts to they should be.   :-//

I'd certainly like it if Rigol added CAN decode to the 1000Z-series, but they've specifically told me they won't.  And lack of time-stamps on segmented captures on the 1000Z is something I've been told they can't add.  Probably some internal architectural detail they're not about to share.

Saying "it's just software", and "it should be able to", and "it is hard to believe" just demonstrates a lack of understanding of how things work in the real world.  And is a denial of the reality of the limitations of products that exist.

When we evaluate and discuss the variety of scopes that are out there, we explore what their capabilities actually are.  That's a learning process, but it let's us weigh the pro's and con's, and select which unit is most appropriate for our specific needs.  The needs aren't the same for everyone, so neither will the devices selected be.  Making suggestions to manufacturers about features or capabilities we'd like to see supported is appropriate.  As is criticism of limitations we feel unnecessarily reduce their value to us.  However, insisting that "strictly speaking", things should be such and so, helps no one, including the person trying to decide which unit is right for them.  Who, as a result, winds up never making any choice at all.
 

Offline pascal_sweden

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #26 on: August 05, 2014, 01:37:23 pm »
You have a valid point about product differentiation, and that they deliberately are not releasing the features.

Regarding limitations on the hardware side, I have a hard time to understand honestly.

The scope has A/D converter on the input. The moment the signal is sampled and available in digital memory, you can basically do everything with it what you want, if you have a decent processor architecture.

CAN is just a matter of releasing support for it.
Time stamps should be the same, as they have a reference clock.

 

Offline marmad

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #27 on: August 05, 2014, 01:47:20 pm »
Regarding limitations on the hardware side, I have a hard time to understand honestly.

The scope has A/D converter on the input. The moment the signal is sampled and available in digital memory, you can basically do everything with it what you want, if you have a decent processor architecture.

Man, look at photos and read descriptions about the insides of the 2 DSOs. They use different A/D converters (the DS1000Z is quad-interleaved), different processors, and, IIRC, the DS1000Z uses one FPGA for post-processing, while the DS2000 uses two. They're NOT the same hardware - and won't run the same software features at the same speed - which is another reason Rigol doesn't try to offer identical features.

Plus, you're discounting one of the HUGE main hardware features of the DS2000 - the spring-loaded Navigation knob. Without that, being able to record and investigate ~60k segments - as well as just moving through Delayed Sweep waveforms - would be a major pain in the ass (not to mention just setting certain variables without it).
« Last Edit: August 05, 2014, 01:59:35 pm by marmad »
 

Offline pascal_sweden

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #28 on: August 05, 2014, 02:35:26 pm »
Yes, the architecture is different of course.

It would be too slow to offer all software features with one FPGA probably, and that's why it comes with a reduced feature set.

The discussions here have been about the need of 4 channels. But if most of the work is digital, then the solution might be to go for MSO2072A? Then you have 2 analog channels, and 16 digital channels. The SPI decoding would be done by the logic analyzer, and no need to sacrifice any of the analog channels.

Maybe I should just go for an MSO2072A. That is, if they make the current SW stable in that version.
 

Offline e_60

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #29 on: January 07, 2015, 03:35:48 pm »
I know this is an older thread, but I could not find any more current thread on the topic.  I have a MSO1104Z which I was looking to use for some quick decoding and confirmation, vs pulling out and connecting a dedicated logic analyzer.  I ran into this same issue discussed above where,   the DataSrc  is  only on trace and greyed out,   so this makes decoding almost useless as I can never see more than a few bytes at a time,   have to keep scrolling horizontally as bytes shift through the event log. Zooming out to get more bytes visible on the screen results in the decoder starting to just show 0's.  I noticed as long as the  horizontail timebase is under 100ms the  decoder is on, if you  try to view more than 100ms it will automatically turn off,  but in practice I cannot even decode 1ms of data on the screen.

 

Offline Howardlong

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #30 on: January 07, 2015, 04:02:56 pm »
Yep, you have to zoom in and decode, it will only do a screen's worth. The event table is therefore pretty much useless.

If you have an idea what you're looking for the serial trigger can be useful, but I wouldn't bet my life on it consistently triggering. That's not a statement that it doesn't work, it does, I'm just not convinced it works all the time.
 

Offline Rigby

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #31 on: January 08, 2015, 03:25:29 am »
Scopes are scopes. Logic analyzers are logic analyzers.  If you dont need realtime visualizing and you just want to capture and decode, get a Saleae and live happy.
 

Offline Mark_O

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #32 on: January 08, 2015, 07:01:28 am »
Scopes are scopes. Logic analyzers are logic analyzers.  If you dont need realtime visualizing and you just want to capture and decode, get a Saleae and live happy.

Well, that's one (extremely simplistic) opinion. 

What about those who don't "just"?  Those who need or want BOTH realtime visualizing, AND the ability to capture and decode longer sequences?  They need a device that does things right.  Which apparently is NOT the MSO1000z series, which has dumbed-down some functionality to the point of being worthless.  That doesn't mean that all MSO's are so limited.

[And BTW, I have used a Saleae, and there were many ways I didn't just "live happy" with it.  In fact, it was quite poor.  So it's no panacea, as you have implied.]
 

Offline Rigby

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #33 on: January 08, 2015, 01:31:16 pm »
well the Saleae is perfect for what I do.  I don't need realtime but I do need to be able to write my own protocol decoders and I need to capture arbitrary lengths of data.  So, yeah the Saleae is useful for me.

I wasn't trying to imply that it is a perfect solution for everyone, because nothing is a perfect solution for everyone, and everyone knows that.

Regarding the MSO1000Z - you get what you pay for, I guess.  How many pieces of test gear can you cram into one inexpensive body before you wonder if it all really works like you imagine it will?

The decoding limitations of the M/DS1KZ are known.  They were known before the MSO1KZ line came along.
 

Offline e_60

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #34 on: January 10, 2015, 03:02:07 am »
I understood going into the purchase there were limitations to the built-in logic analyzer of this lower end oscilloscope, however I did not anticipate that the functionality would be so heavily crippled.   I made an assumption that I would be able to decode the captured memory,   the manual specifically described the function of decoding from trace as default, not as the only choice… there is an event table and payload screen which further suggests you will be looking at more than a few bytes.   I don’t think my assumption/expectations were unreasonable. 

I picked up an MSO2072A yesterday which so far does exactly what I expected from it as a logic analyzer, and the ribbon cable is much nicer than the MSO1000Z one.
 

Offline pickle9000

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #35 on: January 10, 2015, 04:34:32 am »
well the Saleae is perfect for what I do.  I don't need realtime but I do need to be able to write my own protocol decoders and I need to capture arbitrary lengths of data.  So, yeah the Saleae is useful for me.

I wasn't trying to imply that it is a perfect solution for everyone, because nothing is a perfect solution for everyone, and everyone knows that.

Regarding the MSO1000Z - you get what you pay for, I guess.  How many pieces of test gear can you cram into one inexpensive body before you wonder if it all really works like you imagine it will?

The decoding limitations of the M/DS1KZ are known.  They were known before the MSO1KZ line came along.

When you are getting a design up and running or if there is a repair a scope with protocol decoding is an excellent tool. Once up, a device like a Saleae is ideal for getting your software up to snuff. There are scopes that can do both but there is always cost to consider.

I personally consider a Saleae a protocol decoder and not a logic analyzer. It is however a very good protocol decoder and useful tool for a programmer.

 
 

Offline Mark_O

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #36 on: January 10, 2015, 10:45:28 am »
I understood going into the purchase there were limitations to the built-in logic analyzer of this lower end oscilloscope, however I did not anticipate that the functionality would be so heavily crippled.   I made an assumption that I would be able to decode the captured memory,   the manual specifically described the function of decoding from trace as default, not as the only choice… there is an event table and payload screen which further suggests you will be looking at more than a few bytes.   I don’t think my assumption/expectations were unreasonable. 

I'd agree with everything you said, 100%.  (emphasis added) 

I believe those are expectations that anyone evaluating the unit would share, based on tech materials that are available.
 

Offline Rigby

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #37 on: January 11, 2015, 12:52:58 am »
The shortcomings mentioned have been mentioned as being present on the DS1000Z series in the software decoding of signals captured on the analog channels, and this limitation is precisely why I purchased my first Saleae device.  I mentioned it in the huge Rigol I2C decoding thread that contains all the rigol hacking info.  No one made a stink about it then, and yeah, I don't know why.  It is a pretty huge limitation.
 

Offline pickle9000

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #38 on: January 11, 2015, 01:22:20 am »
Sounds like Saleae are having issues, prices going up.
 

Offline Rigby

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #39 on: January 11, 2015, 11:04:53 pm »
Sounds like Saleae are having issues, prices going up.

Yeah.  Shame because they have really good stuff.  If this helps them get back in black I'm on board.
 

Offline smgvbest

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Re: Rigol Ds1074z I2C Decode event table only shows one packet.
« Reply #40 on: January 14, 2015, 04:12:01 am »
I posted this over in the DS1000Z wishlist thread and thought I would duplicate it here.  I hope you do not mind

Quote
I had asked Rigol about the Decode working on screen only and was informed the DS1000Z series has very little FPGA space left.
I would assume if that is true they are keeping their Limited resources for bug fixes not features and I would assume they are looking across the whole product line which includes the MS01000Z as well.   So while implementing the decode may work on a base DS1000Z the MSO1000Z would run out of space so that makes the feature something that can not be implemented.

From a support POV if this is true it would be a nightmare.   If they implemented the better decode on the DS1000Z but did not on the MSO1000Z I know I would be upset because I paid more for scope with LA capabilities so to have the support in the DS but not MSO would upset users so Rigol would be in a bad position.   Best stance as a company is to fix bugs but not add features that can not be supported across the whole line of the supported boards.

Thats mine opinion FWIW based on a simple reply from Rigol,  take it for what it's worth.

I do say that the decode function is not worth buying if this is the case.
Sandra
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