REVIEW - Owon SDS7102 - A look at the SDS series from Owon

[0xdeadbeef]

Ok, nice freeze
Honestly I didn't really test the FFT much as this is a feature I never really need. And Autoset is nothing I normally use either.
Also note that I have a v1.0 firmware though I suspect the 8102 firmware numbering differs from the 7102. But it's a pretty old version anyway...

[rf-loop]

There is nothing wrong with making mistakes. They just need to be documented and fixed. Not offering public downloads and change history might have other reasons (like trying to avoid fw hacking), but usually it stems from the idea that making bugs is something to be ashamed of and therefore trying to conceal it.

This is also partially cultural difference. This is one thing Chinese manufacturers need learn. But it can not go so that Chinese learn and we do nothing. Also we need accept and adapt to cultural differencies. They need littlebit more open mind and no need ashame if some bug or wrong design. We need lean how to do negotiations so that also they do not feel loose faces. If people talk to chinese same as he talk to western manufacturer he loose his game. Best what we can do is co-work style to solve problems together.  If someone go just like showing with finger directly with big noise "you have make wrong" this method do not work.
But one main problem is nearly as paranoic afraid of copycats. This problem they have develop themselves.

Btw. if peoples want hackable scopes, why not do this? (some hidden design so that it seems like factory try secure it not hackable but still keep some door open.. . and peoples are interest. (I littlebit think that someone have find this idea...what happend if Rigols change two bits... maybe selling decay becouse not anymore hackable, and they know what are these bits, hack "door" can close without any money.)

Revision history / Ghangelog and even buglog.
This I hope all do who make things with upgradeable FW.

[rf-loop]

BTW: it's a bit weak that you can't save both channels at the same time. Also the "copy" button always saves the waveform, even if you defined saving to bitmap in the "save" menu.

Both channels at same time. This is nice if have but it is also littlebit difficult. (not exactly difficult but they need store separatelly. One after one to the USB  memory. They can not merge if do not change "everything".

File structure is 69 bytes header what include all information about scope and settings, after then come data what include only ADC 8 bit signed integers.  If do both channels store it need (with this datastructure) only store one whole channel file after one. This can of course do automatic if add this feature to FW. It last twice time and scope need keep frozen whole this time. This feature, store both, have not implemented and user need himself first store other and then store other.  If want do one file, well all need do new. Both channels may have different settings, voltage and shift.

I hope they change "copy" button function. It need follow what user have selected in "save" menu. If I have selected "picture" then it save picture. If I have selected wave it then save this captured ADC data. This make scope more fast to use becouse need only push one button for save wave or picture as user have preselected in save menu.
Some this kind of development (many small things) is nice if they can do for FW after collected some good amount of users opinions.
I'm very happy if some manufacturer do so that just before some new model is ready to markets they collect some independent professionals for make useabilitys tests, then collect opinions and make final version.
Also some info on the screen need name different.

Where from come example M:  what it means... yes after 5 minutes you learn and remember it is time/div. In some cases chinese language is more nice, it is more powerful if look how much information short phrase can contain. Information density is (mostly) much higher than western alphabetical languages where all info is in serial gueye.  And voltage is V, mV, not v, mv.
But it is nice that they can write western alphabeticals.
Try turn you scope menu language to chinese. maybe it is more nice.

[0xdeadbeef]

Ok, the good news is that Owon finally responded. The bad news is that I don't get an update yet...

Dear Sir,
Thanks for your support to OWON products.
We'll give u a upgrade software to solve your problem but needs some time.
After finishing, we'll send to u.

And one pretty bad thing that I just noticed and that I wasn't really aware of when selecting the 8102: the 2GS/s (1ch) and 1GS/s (2ch) sampling frequency is only possible for record lengths of 10k or less. With more than 10k record length, the sample frequency is automatically reduced to 1GS/s (1ch) and 500MS/s (2ch).
So I guess if you want to use the large record lengths, the 8102 is effectively the same as a 7102.

[marmad]

And one pretty bad thing that I just noticed and that I wasn't really aware of when selecting the 8102: the 2GS/s (1ch) and 1GS/s (2ch) sampling frequency is only possible for record lengths of 10k or less. With more than 10k record length, the sample frequency is automatically reduced to 1GS/s (1ch) and 500MS/s (2ch).
So I guess if you want to use the large record lengths, the 8102 is effectively the same as a 7102.

Is that actually confirmed anywhere in the literature or documentation for the 8102?  That doesn't seem right.  Make sure you confirm with another owner that they have the same issue (maybe bertchai?).

[0xdeadbeef]

Well, I was not aware of this limitation, as IMHO it's not mentioned in either the technical specs nor the manual.
Indeed Owon advertises the SDS like this on their site: "10M record length with highest 3.2GS/s sample rate".
Now I guess you'd need to read this as "up to 10M record length" and "up to 3.2GS/s" sample rate and not as "10M record length at 3.2GS/s".

On a 2nd thought, that limitation makes sense if you consider that the common understanding ist that all SDS models share the same hardware (apart from the ADC). So they also share the same memory bandwidth. Quite obviously you'd need twice the bandwidth for a 2GS/s sample rate. So probably the Owon is limited to the FPGA internal block RAM for any sample rate >1GS/s.

Of course everybody with a 8102 or even 8202 is invited to confirm this limitation. I also asked the Owon customer service about it, but based on my experience, it will take them a few days to answer. And honestly I can't imagine that this is a firmware bug.

[marmad]

On a 2nd thought, that limitation makes sense if you consider that the common understanding ist that all SDS models share the same hardware (apart from the ADC). So they also share the same memory bandwidth. Quite obviously you'd need twice the bandwidth for a 2GS/s sample rate. So probably the Owon is limited to the FPGA internal block RAM for any sample rate >1GS/s.

Yes, I suppose it makes technical sense, given the hardware - but it's something that should be addressed in the specs or manual.  To me, that would be grounds for returning the scope for a refund  (if that's what you wanted to do) - since it's a fairly big thing.  OTOH, perhaps you might consider swapping down to a 7102 - it costs quite a bit less for just the loss of the higher sample rate at 1K and 10K.

[Chinakoch]

I tried to get some information regarding the USB protocol specifications via the Owon customer support. As I am not a native speaker my English might not be the best, but at least people understand what I am writing. Unfortunately the person in the customer support does not seem to understand what I want:

Dear Grace,
sorry, for not explaining myself clearly. I do not ask for a Linux or
Mac Version of the software, but for the specifications of the data
protocol used for communication with the oscilloscope. These
specifications are independent of the operating system. We are running
several research projects using Linux machines and it would be very
helpful if I could read data from your oscilloscopes with these
machines. If you could provide me with the USB protocol specifications,
I could develop a driver that enables me to read data from your
oscilloscopes using our Linux machines.

Please tell me, if you can provide me with the data protocol
specifications or not.

Kind regards,
   XXXX

Am Montag, den 17.10.2011, 16:50 +0800 schrieb service:
> ?
> Hello XXXX,
> It can only support WINDOWS.
> 
> 
> Best Regards,
> Grace
> OWON Service Team
> ------------------------------------
> Xiamen Lilliput Technology Co., Ltd.
> Website: www.owon.com.cn
> Mail address: service@owon.com.cn
> Tel: +86 592 2575666
> Fax: +86 592 2575669
>
> 
> 
> ? XXXX
> ?? 2011-10-17  15:08:13
> ? service
>
> Re: SDS series USB protocol specifications
> 
> Dear Grace,
> as I have mentioned in my previous eMail, I am not asking for the
> current version of the Windows software you offer, but for the current
> specifications of the USB protocol, so that it is possible to get data
> from the scope using also e.g. MacOS or Linux. I have found
> specifications for older Owon scopes here:
>
> http://sourceforge.net/projects/owondriver/files/
>
> Unfortunatly, these specifications do not seem to be up-to-date. I am
> therefore kindly asking, if you could provide me with an up-to-date
> version of the USB protocol specifications.
>
> Kind regards,
>   XXXX
>
>
> Am Montag, den 17.10.2011, 08:52 +0800 schrieb service:
> > ?
> > Dear Sir,
> > Thanks for your support to OWON products.
> > The newest software can be found on our websit.
> > FYR:
> > http://owon.com.cn/eng/technology.asp?types=SDS
> > 
> > Hope these  can help you and still have any problem,pls let us know.
> > 
> > 
> > Best Regards,
> > Grace
> > OWON Service Team
> > ------------------------------------
> > Xiamen Lilliput Technology Co., Ltd.
> > Website: www.owon.com.cn
> > Mail address: service@owon.com.cn
> > Tel: +86 592 2575666
> > Fax: +86 592 2575669
> >
> > 
> > 
> > ? XXXX
> > ?? 2011-10-16  02:26:07
> > ? service
> >
> > SDS series USB protocol specifications
> > 
> > Dear Madam or Sir,
> > I have recently purchased an SDS7102 oscilloscope. I would certainly
> > like to run the Windows software that was provided with the scope.
> > Unfortunately, the PC I use for measurement runs Linux for different
> > reasons. I found some specifications regarding the USB protocol for
> > communication with older versions of Owon scopes (PDS series) and tried
> > to use these specifications to implement a simple driver in Python.
> > Obviously the specifications seem to have changed for the SDS series, as
> > bulk-reading from the scope times out when sending the start command. I
> > guess, that it might be the endpoints or the start command that have
> > changed. Anyway, I kindly ask, if you could provide me with an updated
> > version of the USB protocol specifications, so that I could develop a
> > linux driver for SDS series oscilloscopes.
> >
> > Kind regards,
> >   XXXX

[amspire]

It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead - no code was ever committed to the svn repository. Probably nothing to do whatsoever with Owon, which means that support will be no help.

You could try contacting Michael:  http://sourceforge.net/users/mgmurphy

[0xdeadbeef]

OTOH, perhaps you might consider swapping down to a 7102 - it costs quite a bit less for just the loss of the higher sample rate at 1K and 10K.

I'm trying to get a definite response first, but indeed I'm toying with the idea to downgrade. Indeed I could send my 8102 back without any reason for 14 days, so I have at least one week left to decide.

[Bored@Work]

It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead -

I see three releases. One from May of this year. Dead looks different to me.

[Bored@Work]

I tried to get some information regarding the USB protocol specifications via the Owon customer support. As I am not a native speaker my English might not be the best, but at least people understand what I am writing. Unfortunately the person in the customer support does not seem to understand what I want:

She understands you very well. But because she can't give you what you want she pretends to not understand what you want. In short, the answer is "No, we won't give you the protocol.". If you continue to try to make your point she will just stop answering

If you are in the EU, you could consider making use of the EU directive which allows a limited amount of reverse engineering for the sake of interoperability.

[0xdeadbeef]

Well, the document ("OWON Oscilloscope PC Guidance Manual 1.1") in the sourceforge archive seems to speak a different language. There is no hint that it could be created by anybody else but Owon and its title (though in pretty bad English) obviously states that it's meant to support Open Source development: "Communication Protocols of USB and Introduction of data format, open source for the third party".
Besides, it would be dumb to not support Open Source development. The Windows application is pretty bad and they should be glad if anybody would volunteer to support the Owon scopes with anything better.

[tinhead]

The Windows application is pretty bad and they should be glad if anybody would volunteer to support the Owon scopes with anything better.

the Windows app is written in java, take a java decompiler, spend 2hrs (with decompiler and USB sniffer)
and you will know everything you wish to know about the protocol.

Even if you spend a day, it will be faster than waiting for an answer from a dumb manufacturer.

[0xdeadbeef]

It always helps if you quote the same you address. As you obviously address Chinakoch, it would have made more sense to quote him than to quote me.

[rf-loop]

This is very clear:

http://ee07m060.wordpress.com/2010/07/14/owon-release-official-specifications/


Problem is now more only that what to talk, how to talk and with who.

It is clear that there is "phone answer machines" also in Owon (letter answering "machines".

If someone is really seriously developing this kind of things for public use I can easy look between lines that Owon is happy if someone want do this.

But it need serious work and not things what make any harm to Owon brand... if there is win-win I thing Owon smile kindly to you and give also some help. But you need find also right person in Lilliput group. Person who understand that it is good for all parties and also person who have enough deep knowledge - and person who can put some his working resources to this.

[Bored@Work]

Well, the document ("OWON Oscilloscope PC Guidance Manual 1.1") in the sourceforge archive seems to speak a different language.

This is the past. Just because someone at some time in the past released that document doesn't mean they will do it now.

Besides, it would be dumb to not support Open Source development.

First, companies do dumb things all the time. In fact, probably 80% of what large companies do is dumb. Chines companies are maybe up to 95% dumbness. So dumb isn't an argument.

Second, why should it be good to spend time and effort to make a tiny minority happy? Until now they manage to sell the SDS oscilloscopes without such a specification, and the majority of those buying such a low-end oscilloscope anyhow couldn't care less about the PC interface.

The Windows application is pretty bad

Exactly because they figured only a tiny minority really wants to use the interface. And they just need to have some software to tick of an item on the requirements list.

and they should be glad if anybody would volunteer to support the Owon scopes with anything better.

And if they don't see the point? If you feel it is your job as a customer to enlight a company, you are welcome to try. The reality is companies don't want to be enlightened.

[amspire]

It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead -

I see three releases. One from May of this year. Dead looks different to me.

May of last year you  mean.  Nothing since.

It looks like Michael got the drivers working for his model of oscilloscopes, along with a few other models owned by other he was in contact with, and left it at that.

There is no sign that this is an ongoing driver development project. No files were ever committed  to  the svn, so it does not look like this was intended as a community opensource project. Just one guy using Sourceforge to publish his code.

It appears Michael did get some data from Owon, so that is why it is worth contacting him.

His email address is in his driver files.

Richard

[rf-loop]

Of course everybody with a 8102 or even 8202 is invited to confirm this limitation. I also asked the Owon customer service about it, but based on my experience, it will take them a few days to answer. And honestly I can't imagine that this is a firmware bug.

Shortly: (I'm now extremely busy so I can not make more tests)

With SDS8202 VGA, (version 1.1.1) I can confirm that 2GSa/s is limited only for 1k and 10k capture memory lenght.
It is not bug, it is feature.  But I do not know how they do it becouse first mutual feel is that ADC do not change clock frequency. (not yet confirmed by measurements directly in the acquisition circuit)

Later I do more lab tests with 8102 and 8202.

But fast overall look, signal sampling quality looks amazing good in this price class, pity it do not have direct 50 ohm (HF impedance) inputs, if it have it is HF-RF peoples's scope..

[0xdeadbeef]

I kinda assumed that this is a bandwidth limitation.
BTW: if you have access to a 8102, could you tell me to firmware version it has?

[rf-loop]

V 2.1.1
Serial prefix SDS81021128
BTW: it is also VGA  version.

[0xdeadbeef]

They have quite a lot of different firmware versions out for a company that claims that the product is mature. Or they use a strange version system.

[rf-loop]

What are all version numbers what you know or have seen somewhere for SDS8102?
I do not know if VGA optin scope and not VGA have different FW. (maybe have)

Please do test:

CH1 or 2 alone used. 10k mem, fast speed (example 1 or 2ns/div.) look stable triggered good quality signal. Use normal capture (not average). Note how it trig and where is trig point. It need be nearly where signal cross trig level.

Turn mem to 100k or 1M. What happend if look where is real trigger point. (trigger time mark related to point where is real trigpoint. Also watch if trigger stability change and how much it add triggerjitter.

I did not have enough time to do deeper test but only I notice that I'm not as satisfied as with 7102

[0xdeadbeef]

Hm, the time between crossing the trigger threshold and the actual trigger seems to vary indeed with the record length, but this also seems to depend on the current timebase (time/div).
Unfortunately, I currently don't have any means to create really strong edges, so going down to 1 or 2ns/div to check the trigger condition is not really feasible.
E.g. at 50ns/div, the signal crosses the trigger threshold about 50ns before the displayed trigger event when using 1k record length. When increasing the record length, this distance decreases to less than 10ns.
Then again, when I repeat the same test at 10ns/div, this behavior is not reproducible and the signal crossing the trigger level will always be around 50ns before the displayed trigger, no matter what record length.
In both cases, there is a certain jitter visible. Then again, my test signal is not very sharp edged and with some noise added, this is to be expected.

[ujda]

I just bought a SDS7102 directly from OWON, I paid $500 USD total to be shipped to
USA, I think I bought the brand new model, which includes a VGA out, a LAN port, and also
a 8Ah Li-Polymer battery. The firmware version is 2.2.1, I am still testing the scope,
more detail will follow.

The reason I bought from them is I want to know if OWON has the model with LAN port,
so I can use the scope remotely.  I saw many people here said there was no such model.
But several websites do show SDS7102 with LAN. I asked many retailers and ebay sellers,
all replied SDS7102 only has two modes: with VGA and without VGA.

So I contacted OWON to clarify this issue, and later a lady replied from   fiona@owonchina.com,
told me they can ship directly to me. Total is $500 include DHL express shipping.
But I have to wire transfer $500 to their HSBC bank account.