REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol

[feds27]

Ah.  I noticed it was just posted to YouTube four days ago.  When I did a search on the thread and forum nothing came up so I posted it.

That's EEVBlog member studio25's video - and the thread where the video is posted (and which is investigating hacking the Rigol) is here. But thanks for posting here - I know it's sometimes impossible to find stuff on EEVBlog  - hell, I often can't find posts I made myself. 

Ah, that's perfect.  Thanks marmad.  Subscribed!

[egonotto]

Hello,

I try the rs232 decode on my DS2072. So far it works pretty good.
But it knows only little ascii symbols.
.,:;-_!"§$%&/()=? is unknown.

The DS2072 is a little analphabet

Here are the dates from my DS2072:
DS2A15050...
Software 00.00.01.00.05
Hardware 1.0.1.0.0
SPU   03.01.02
WPU  00.06.00
CCU   12.29.00
MCU   00.05

Best Regards
egonotto

[marmad]

Hello,

I try the rs232 decode on my DS2072. So far it works pretty good.
But it knows only little ascii symbols.
.,:;-_!"§$%&/()=? is unknown.

The DS2072 is a little analphabet

Thanks, egonotto. Any chance you can save the RS-232 waveform with the undecoded symbols as a WFM file and get it to me? Or post it here as a .zip file?

[egonotto]

Hello marmad,

i generate the signal with Scanalogic-2 a little logic analyser. Therefore the pegel is no true RS232.

I use the script:
BAUD=9600
b1
UCHR=Hello world
UCHR=0123456789
UCHR=.,:;-_!"§$%&/()=?
UCHR=End of text

The hex on DS2072 are ok. So DS2072 can decode the signal well.
Only the ascii  presentation has gaps.

Best Regards
egonotto

[marmad]

i generate the signal with Scanalogic-2 a little logic analyser. Therefore the pegel is no true RS232.

Thanks, egonotto. I was planning to test it on other versions of the FW - but I just remembered that Rigol changed the WFM format again in v.01.00.00.03 - so I can't load it.    Sorry, but can you try saving it one more time as CSV instead?

[egonotto]

Hello marmad,

now the rs232_csv_max file

Best Regards

[marmad]

Hello marmad,

now the rs232_csv_max file

Best Regards

Thanks    I'll let you know what I find out,

[neilhao]

Hi guys,

I did a little about measuring EMI using DS2202, details can be found at https://www.eevblog.com/forum/projects/idea-about-measure-emi-using-oscilloscope/

I have a little question about the bandwidth of the FFT, it seems the BW of the DS2202 is far higher than 200Mhz?

[marmad]

Hello marmad,

now the rs232_csv_max file

Best Regards

@egonotto: I haven't been having any luck trying to create a usable new version of the RS232 WFM for FW post-v.01.00.05. So I would suggest you upgrade to v.01.00.00.03 (you can always downgrade back to v.01.00.05 if you want). Then test the RS232 again on the new FW - and also create a new version WFM file that we can pass along to Rigol if it still isn't decoding those characters.

If you don't have copies of FW v.01.00.00.03 and FW v.01.00.05, send me a PM (or email) with your email address, and I'll send them to you.

[marmad]

I try the rs232 decode on my DS2072. So far it works pretty good.
But it knows only little ascii symbols.
.,:;-_!"§$%&/()=? is unknown.

Added to the bugs/issues list - and passed along to Drieg/Rigol.

[Wim13]

Hi guys,

I did a little about measuring EMI using DS2202, details can be found at https://www.eevblog.com/forum/projects/idea-about-measure-emi-using-oscilloscope/

I have a little question about the bandwidth of the FFT, it seems the BW of the DS2202 is far higher than 200Mhz?

Here some FFT pictures from my 2072 ( 70 Mhz) at 100 , 300 and 500 Mhz,
it is correct to the bandwidth measurements, -10 db at 300 Mhz and -20 dB at 500 Mhz ( 2 div down )

In FFT it is all in dB and in this example 10 dB per div, which gives a total different view.

Edit: the input level knob of the DSO, has no influence on the dB range displayed, has only impact on the S/N and noise floor

Edit2: In later post you can find a graph of the differences of the Bandwidth of the 2072 nad 2202

[marmad]

Effects of using AUTO memory depth setting on DS2000s.

Two interesting things to note:

1) The AUTO setting is obviously meant to optimize the sample length to keep the sample rate as high as possible - but for some reason, Rigol decided to not use sample lengths beyond 14MPts. Perhaps because that's the standard maximum without the added option?

2) I wonder why at time bases < 500ns/div (which is where 14kPts @ 2GSa/s fills the display) the waveform update rate is not getting faster than when you just use the 14kPts setting? Obviously, the sample length is being decreased and the acquisition time is getting shorter - so the number of waveform's being captured should be higher than for a fixed 14kPt length - but it isn't.

[g2]

I have had a Rigol DS2072 and I Got An Electric Shock from it.
I was using  a 2 wire extension cord without ground (earth).
 I found out when Rigol DS2072 is not grounded, there is 115 volt on  Chassis ground,
and independently  of the switch are On or Off.
If I switch Off the neutral wire, and Rigol DS2072 only get the phase, I got 230 volt on Chassis ground, and also on probe tip.
From Rigols user guide: Ground The Instrument. The instrument is grounded through the Protective Earth lead of the power cord. To avoid electric shock, it is essential to connect the earth terminal of power cord to the Protective Earth terminal before any inputs or output.
Of course it is best to ground the instrument; but I have many other electrical appliances that are not grounded and do not  do that. And I do not have ground (earth) in most of the rooms  in the house.
Is  Rigol DS2072 OK ??
Is it only my Rigol DS2072 that  is defective ?
How are other digital oscilloscopes ?
Do I have  to  change the house's electrical installation with ground  (earth)  ?

[Hydrawerk]

And I do not have ground (earth) in most of the rooms  in the house.

Are you from Russia??
Your scope is probably OK, but provide it a proper ground.

[g2]

And I do not have ground (earth) in most of the rooms  in the house.

Are you from Russia??
Your scope is probably OK, but provide it a proper ground.

No, i am from Denmark. First in ca 1995 the installation off ground in all room in a house started.
All other instrument I have do not have that. and the do not have ground

[alank2]

So guys, I'm thinking about possibly getting a DS2072 someday - my question is what is the deal with the demo features?  It comes with all of them enabled for a period of time?  How long?

[marmad]

I have had a Rigol DS2072 and I Got An Electric Shock from it.
I was using  a 2 wire extension cord without ground (earth).
 I found out when Rigol DS2072 is not grounded, there is 115 volt on  Chassis ground,
and independently  of the switch are On or Off.
Is it only my Rigol DS2072 that  is defective ?
How are other digital oscilloscopes ?
Do I have  to  change the house's electrical installation with ground  (earth)  ?

Other oscilloscopes are the same (except for specially-built ones with isolation - I have a Tektronix battery-operated analog scope that is double-insulated). What you were doing is dangerous - and there is lots of information about it online; the DSO MUST be grounded.

Dave even made a video which talks about the fact that the DSO chassis (and all BNC connectors) are shorted to Earth ground (and how to avoid accidents when probing).

[marmad]

So guys, I'm thinking about possibly getting a DS2072 someday - my question is what is the deal with the demo features?  It comes with all of them enabled for a period of time?  How long?

Yes - 36 hours of ON time - although they're reasonably easy to just keep restarting.

[Hydrawerk]

Same as on my DSOX2002A and my father's DSOX3000 at his company. It's probably not a bug.

[egonotto]

Hello Hydrawerk,

if you anser at my posting that I erase.
If the trigger level is AC coupled I now understand a trigger level line makes no sense. So I erase my post.

Best Regards
egonotto

[Hydrawerk]

Well, I am not sure, someone told me that the trigger indicator is always visible on TDS2000 scopes... 

[g2]

Same as on my DSOX2002A and my father's DSOX3000 at his company. It's probably not a bug.

Thank you for testing. But it just tell that all Rigol oscilloscopes, is real bad isolated from main power(230V).

[g2]

I have had a Rigol DS2072 and I Got An Electric Shock from it.
I was using  a 2 wire extension cord without ground (earth).
 I found out when Rigol DS2072 is not grounded, there is 115 volt on  Chassis ground,
and independently  of the switch are On or Off.
Is it only my Rigol DS2072 that  is defective ?
How are other digital oscilloscopes ?
Do I have  to  change the house's electrical installation with ground  (earth)  ?

Other oscilloscopes are the same (except for specially-built ones with isolation - I have a Tektronix battery-operated analog scope that is double-insulated). What you were doing is dangerous - and there is lots of information about it online; the DSO MUST be grounded.

Dave even made a video which talks about the fact that the DSO chassis (and all BNC connectors) are shorted to Earth ground (and how to avoid accidents when probing).

Dave's  video  is about measurement and connection to other  electrical appliances, and what can  happen.
When Rigol DS2072 is not grounded, it have 115 Volt  (or 230 Volt) on chassis and also on probe tip.
Completely without being connected to other equipment.
All my old analog oscilloscopes I have had, do not have 230 V out on  Chassis ground, and also on probe tip. And all other  electrical instruments I have do not have it.
Rigol DS2072 must be bad isolated from main power(230V).
Are other digital oscilloscope brands also poorly insulated ?
Of course, it is best to ground.

[Harvs]

Dave's  video  is about measurement and connection to other  electrical appliances, and what can  happen.
When Rigol DS2072 is not grounded, it have 115 Volt  (or 230 Volt) on chassis and also on probe tip.
Completely without being connected to other equipment.
All my old analog oscilloscopes I have had, do not have 230 V out on  Chassis ground, and also on probe tip. And all other  electrical instruments I have do not have it.
Rigol DS2072 must be bad isolated from main power(230V).
Are other digital oscilloscope brands also poorly insulated ?
Of course, it is best to ground.

So I just did a few checks.  From measureing the mains input socket with an LCR meter, there's a common mode filter with 4.7nf caps between N-G and A-G.  There's no blead resistance across the caps and ground (I am not saying there should be.)

So under controlled conditions I removed a ground, powered it up, and got what you described.  This is as to be expected, the 4.7nf caps are forming a voltage divider to earth at the input CM filter, and so earth is now half way  between neutral and active potentials.  In Oz, with a 240V active and neutral at close enough to ground, this gives ~ 120VACrms on the jacks.

Shorting this to ground gives a current of 338uArms, which if you work out 1/(2*pi*f*C) on 4.7nf, and divide 240Vrms by it, you’ll get exactly that.

It’s got nothing at all to do with insulation, it’s designed that way to remove mains line noise (and vice versa.)  So just operate it with a ground and you’ll be fine.

[Harvs]

To answer the second part of your question, is it common?  Yes, very.  It's needed to meet EMI/EMC compliance when you've got a switching power supply.

Attached is a photo of the IEC input socket on a high end computer power supply I happen to have in pieces.  You can also see here they've done exactly the same thing.  If I connected this PC without a ground, I'd have 120Vrms on the PC case.