Rigol DHO804 Test and Compare Thread

[ebastler]

Which is all consistent with what we said all the time, right? The sweep time defines the time window which gets decoded.

[Martin72]

I added the siglent, which does exactly the same thing.
Here 100ms with both scopes, both show 75 lines in the table, the packages can only be recognised as dashes - I can't imagine that the scopes can decode this if they don't decode from memory.
(By the way: I like the table colour of rigol much better, have I said that before?   )

Edit: Traces are hided on the siglent, forgot to set it back. Edit2: Why does the rigol shows "too many results" but still decode correctly..

[Martin72]

Hi,

See #825 and yes I've also tried with max memory (25Mpts because of 2 channels active).
Look at the amount of memory the siglent got(Automode), it doesn't matter at all.

Edit: Post was erased...

[Fungus]

See #825 and yes I've also tried with max memory (25Mpts because of 2 channels active).
Look at the amount of memory the siglent got(Automode), it doesn't matter at all.

Try disabling roll mode and set it to 1s/div or something like that. You can grab several seconds of data.

[nctnico]

Try to figure how to drive the number of messages in that table display and you'll know it.

Just tried it out, you can only change the number of decoded packages displayed via the time base.
If you set it to 50ms, you have 15 packages. 37 packages
If you set it to 10ms, you get 7.
If you now use the manual allocation of the memory and set it to e.g. 10Mpts, the number of packages displayed remains at 7, although the memory is now much more than in auto mode.

If you zoom out (if there is off-screen data), you should be able to see more packets in the decoding table (up to the limit). And what happens with the number of packets in the decode table when you zoom in? Both in stop mode BTW so the acquisition record is fixed.

[Fungus]

Yes, because you didn't record for longer time, you only increased the sample rate.

The amount of serial data you recorded stayed the same, ie. 100ms (7 packets).

[Martin72]

@nctnico:



Something like this will happen.

[nctnico]

That answers my question! Thanks for taking the trouble to show it in a video 

[Martin72]

No problem, its better than posting pics - But now to the interesting part:
Does it decode from the memory in the last part of the video ? 

[nctnico]

No problem, its better than posting pics - But now to the interesting part:
Does it decode from the memory in the last part of the video ? 

Yes. There is (acquired) data outside the visible area when you pressed stop. By zooming out, you increased the timespan and brought the packets which where invisible before into the visual 'range' so the DHO804 decided to try and decode that part of the acquisition as well.

[ebastler]

But now to the interesting part:
Does it decode from the memory in the last part of the video ? 

The I²C code shows with approx. 70 bits/div in your last scope setting. Even at an ideal 2 pixels/bit, it would take 2*70*10 pixels to resolve these on the screen, which is more than what the screen provides even in full-screen mode. So it can't be decoding from the screen buffer, right?

[Martin72]

The same scenario again, only with the siglent hd.
It has memory management on board, so I was able to set it to 100Mpt* and zoom out accordingly.



*) 200Mpts if I had used channel 3, but that doesn't matter in this case.

[Martin72]

Hi,
Got the rigol DS1054Z out of the cupboard at work today to try out this decoder thing on it (unfortunately forgot the usb stick with pics at work).
It's true, for the one I2C test you set the time base to 1ms, then the DS1054Z decodes one word.
If you set it to 2ms, then it decodes nothing...
But what I found really "scary" was that I took the scope out of the cupboard for the first time in a while - and compared to the DHO, it seems downright "antique" to me.

[Fungus]

But what I found really "scary" was that I took the scope out of the cupboard for the first time in a while - and compared to the DHO, it seems downright "antique" to me.

Yep.

I bet the non-touch Siglents aren't much different either.

I'm going to get my Micsig out this week and see which one I want to keep. 

[Martin72]

I bet the non-touch Siglents aren't much different either.

Exactly.
Once you've experienced the benefits of a touchscreen, you're dead to the other way of operating devices.

[Martin72]

In the next few days I will show you an example of how drastic the difference can be, even with things as ordinary as choosing the right divisor factor.
With the DHO and the siglent touch models this is a matter of a few seconds, with the DS1054Z and the 1104X-E you first have to call up the menu and then scroll through the divisions with the action button.
This is no longer up to date, but you can forgive them, they are a bit older.

[Fungus]

This is no longer up to date, but you can forgive them, they are a bit older.

Yes, but if you're going out to buy today... not even on the shortlist, right?

[2N3055]

This is no longer up to date, but you can forgive them, they are a bit older.

Yes, but if you're going out to buy today... not even on the shortlist, right?

Like we said before many times, there are still many things DS1104X-E can do that DHO800 cannot.
It is only a question if that matters to you or not.

[Fungus]

there are still many things DS1104X-E can do that DHO800 cannot.

You mean things that require more hardware?

[2N3055]

there are still many things DS1104X-E can do that DHO800 cannot.

You mean things that require more hardware?

And when people call you a troll and Rigol apologist and shill you seem to get offended.

But all you ever offer is never ending innuendos and spreading of vague denialism.

Facts are out there. Go back and read again.

[ebastler]

Like we said before many times, there are still many things DS1104X-E can do that DHO800 cannot.
It is only a question if that matters to you or not.

Since I just decided to spend the money for an SDS2104X plus, which punches one weight class above, I consider myself impartial in the "DHO800/900 vs. SDS1104X-E" debate now. Early bugs aside, here's my take -- purely a summary of what I have learned from the forum, I don't have first-hand experience with either scope:

• Regarding core scope functionality -- waveform acquisition & display, triggers, measurements, decoders -- the two seem pretty much on par. Some advantages here or there for one or the other, but no clear winner.

• The DHO800 "package" has several unique aspects: Touch screen, very portable, VESA mount, HDMI out, supply from external power bank possible. If you want these, they will tip a "new purchase" decision towards the DHO. If you want them a lot, they may even convince some 1104X-E owners to switch to a DHO.

• If you want Bode plots and/or MSO functionality, the DHO800 does not offer these at all. You would have to buy the DHO900, spending several hundred USD or EUR more. The DHO900 will provide digital inputs and an AWG which are more integrated into the scope than in the SDS1104X-E, where both are fully external units. This also means that you can buy or build a DIY logic probe for the DHO, while you have to buy the relatively expensive Siglent probe for the SDS, which reduces the price difference significantly. On the other hand, if you only want Bode plots and already have a Siglent AWG, that's a strong argument in favor of the Siglent.

Did I forget anything major?

[Fungus]

Facts are out there. Go back and read again.

Fact: The DHO800 can do many things the SDS1000X-E cannot.

[2N3055]

Facts are out there. Go back and read again.

Fact: The DHO800 can do many things the SDS1000X-E cannot.

That is PARTIAL fact.

FULL Fact is that it is true both ways...

Ebastler  nicely quickly summarized it. There are few more details but those are details.

EVERY device, even 1M USD 100 GHz scopes have pros and cons. It is a list.
Which people look at and decide what is important to them or not.

You should start adding a new phrases to your vocabulary. It is :"to me." and "for me".

Example of use in sentence: "The DHO800 can do many things for me that SDS1000X-E cannot."
or: "Yes, but if you're going out to buy today... for me not even on the shortlist, right?"

And I would not have said a word.

[Mechatrommer]

If you want Bode plots and/or MSO functionality, the DHO800 does not offer these at all. You would have to buy the DHO900, spending several hundred USD or EUR more.

i hope soon DHO800 will be upgradable (hackable) to bode plot capable... hopefully at less than $100 cost...

You We should start adding a new phrases to your our vocabulary. It is :"to me." and "for me".

here corrected for you cheers.

[2N3055]

If you want Bode plots and/or MSO functionality, the DHO800 does not offer these at all. You would have to buy the DHO900, spending several hundred USD or EUR more.

i hope soon DHO800 will be upgradable (hackable) to bode plot capable... hopefully at less than $100 cost...

You We should start adding a new phrases to your our vocabulary. It is :"to me." and "for me".

here corrected for you cheers.

Yeah, you are the one with moral right to claim so....