Rigol DG4xxx Signal Generator - Burst mode BUG

[GonzoTheGreat]

It would be good for Shahriar to show these bugs as a follow up on the DG4162 video that he did a while ago.  Maybe Rigol will take notice....
Is anyone here in contact with him?

[miguelvp]

It would be good for Shahriar to show these bugs as a follow up on the DG4162 video that he did a while ago.  Maybe Rigol will take notice....
Is anyone here in contact with him?

I believe member Hugoneus knows him well
https://www.eevblog.com/forum/profile/?u=8240

[OldNeurons]

Another bug.

Setup:
Rigol DG4062, firmware revision 00.01.10
Metrix MTX3293 connected to DG4062 channel 1 output.

All voltage measurements below are averaged values over 30s.

Steps to reproduce:
01- Let your DG4062 warm up for 30mn.
02- Reset it to factory defaults. 'Preset' / O.K.
03- Waveform / Arb / SelectWform / Builtin / Common / DC / Select / Arb
04- Switch ON Output Channel 1
05- At this stage, you should read someting close to zero on your DMM (60µV in my case).
06- Set 'Offset' value to 50mV. You should read something close to 50mV (50.033mV in my case).
07- Switch Waveform type from 'Arb' to 'Sine'
08- Switch Waveform type from 'Sine' to 'Arb'
09- Voltage, in my case, jumps to 55.555mV (5.5mV increase).
10- Set 'Offset' value to zero.
11- Switch Waveform type from 'Arb' to 'Sine'
12- Switch Waveform type from 'Sine' to 'Arb'
13- Voltage, in my case, goes back to zero (60µV in my case).

This "I don't know what" remains somewhere at 5.5mV for Offset values ranging from zero to 2.0000V.
From 2.0001V to 10.0000V, this "I don't know what" jumps to 30mV.
This jump corresponds to a relay status changing internally (you can here a click when going from 2.0000V to 2.0001V.

I am curious to read your findings.
Thanks for your feedback.

[Teneyes]

Another bug.
Setup:
Rigol DG4062, firmware revision 00.01.10

07- Switch Waveform type from 'Arb' to 'Sine'
08- Switch Waveform type from 'Sine' to 'Arb'

Let's Call this the Arb-Sine-Arb BUG
Yes I can Confirm it, FW 1.08
So Attached is Gif of these steps:
   1. Arb-> Sine -> Arb ,with Arb DC set =0.0mV. ,          frames 1-15
   2. ArbDC =1.0mV.                                                       frame. 16
   3  Arb -> Sine -> Arb BUT ArbDC comes back as 3.6mV.    frames. 17-45
   4. ArbDC = 0.0 mV  .causes a Step of -1mV to 2.6mv    Frame  37
   5 Arb-> Sine -> Arb  and offset back to 0 mv.                frames 38- 62

So it looks like the Sine Func corrupts the offset parameters for the Arb DC function.
Was it because my sine wave function changes DC relays?

[GonzoTheGreat]

I confirm the Arb-Sine-Arb bug with firmware v1.08

[GonzoTheGreat]

I noticed a fourth bug!

Namely, the SYNC output is not synchronized with the period of the waveform appearing on the OUT output generated with the "Harmonic" menu for certain 3rd order waveforms.

By "not synchronized" I do not mean a constant phase difference.  I mean a variable phase difference between the OUT and SYNCH outputs.  The phase fluctuates wildly - maybe even 100º   

Now, I am trying to figure out for what harmonic amplitudes this bug occurs...

[Tom D]

...The phase fluctuates wildly - maybe even 100º   

Maybe the climate of Antarctica is wreaking havoc on your unit? 

Tom

[GonzoTheGreat]

Maybe the climate of Antarctica is wreaking havoc on your unit? 

No, I have a good bon fire going.

Both of the bugs I have reported were replicated by others from warmer climates.
I'd wager the 3rd one will be replicated, too, once I post detailed replication instructions.

[Tom D]

Thanks, Gonzo. I was looking at buying one of these, so I've been following this thread with interest. Nevertheless, I'm somewhat perturbed by your findings - I'm sorry to hear that you are having issues. I hope that this is only a firmware issue that will be resolved fairly quickly.

Tom 

[Teneyes]

Thanks, Gonzo. - I'm sorry to hear that you are having issues. I hope that this is only a firmware issue that will be resolved fairly quickly.

It would be proper for Gonzo to modify the first post of this thread to indicate all bugs and in which Firmware revision the bugs exist and if the bug was corrected in later firmware . 

To be realistic, Rigol will evaluate a bug report and decide if it will be corrected.

I have report bugs, and only after 18 months and,
after the bug continued on to the next generation of devices and
Dave Jones highlighting the bug did Rigol correct it.

These bugs on this thread are small, so just but be aware of them.

[OldNeurons]

These bugs on this thread are small, so just but be aware of them.

I do not consider bug#1 as a minor one, but as a major one.

It would be proper for Gonzo to modify the first post of this thread to indicate all bugs and in which Firmware revision the bugs exist and if the bug was corrected in later firmware . 

Yes, good idea.
Gonzo, do you intend to do so?

To be realistic, Rigol will evaluate a bug report and decide if it will be corrected.

I have report bugs, and only after 18 months and,
after the bug continued on to the next generation of devices and
Dave Jones highlighting the bug did Rigol correct it.

Software is everywhere. In your car, your fridge, your oscilloscope ...
Testing and debugging a new software is time consumming and costs money.
Well, this is one of the reasons why some products are cheaper than other. They live factories before completion ... and final debugging is made by the end consumer.
O.K., in our case, I have no problem to live for a certain period of time with a product which is only 95% finished.
But, when end consumers take a part of their time to properly describe and report issues to the manufacturer, and when this go unanswered and without any corrective actions, then I start to have a problem, and this kind of situation will certainly affect my future equipments choices and recommendations ...

I also found on my side another bug, not a serious one, but too much for me ... At the end, I will need a kind of 'Warning list' attached to this device  .

I'll come later with a description.

[OldNeurons]

So, here it is ...

Description:
Signal modulation stops when modulation shape is changed.

Setup:
Rigol DG4062, firmware revision 00.01.10
Rigol DS2102A for signal monitoring.

Steps to reproduce:
01- Reset DG4062 to factory defaults. 'Preset' / O.K.
02- Switch ON Output Channel 1
03- Press MOD. At this stage, you should observe a sine signal with 100% AM.
04- Change SHAPE to SQUARE, TRIANGLE.. or whatever you want. At this stage the signal goes OFF.
06- To restore the signal, there are 3 solutions. Press MOD 2 times, or press OUTPUT OFF and ON, or change the AM Depth to a new value.

When AM Depth is different than 100% and SHAPE is changed, the signal freezes at low level of AM Depth value.

If carrier signal is PULSE, instead of any other, then when changing SHAPE or DutyDev in the MOD menu, PWM will stop. Same medecine than above applies to recover...

Still curious to get your feedback with same or different firmware version.
Thanks.

[GonzoTheGreat]

It would be proper for Gonzo to modify the first post of this thread to indicate all bugs and in which Firmware revision the bugs exist and if the bug was corrected in later firmware . 

Yes, good idea.  Gonzo, do you intend to do so?

I will do it.
I think all bugs replicable on firmware v1.08 and v1.10, correct?
I am a bit fuzzy about v1.09 though...

Also, do you want me to add the Arb-Sine-Arb bug to the first post ?

[OldNeurons]

Also, do you want me to add the Arb-Sine-Arb bug to the first post ?

Yes, sure, and also the last one "Signal modulation stops when modulation shape is changed."

[GonzoTheGreat]

Description:
Signal modulation stops when modulation shape is changed.

Setup:
Rigol DG4062, firmware revision 00.01.10
Rigol DS2102A for signal monitoring.

Steps to reproduce:
01- Reset DG4062 to factory defaults. 'Preset' / O.K.
02- Switch ON Output Channel 1
03- Press MOD. At this stage, you should observe a sine signal with 100% AM.
04- Change SHAPE to SQUARE, TRIANGLE.. or whatever you want. At this stage the signal goes OFF.
06- To restore the signal, there are 3 solutions. Press MOD 2 times, or press OUTPUT OFF and ON, or change the AM Depth to a new value.

When AM Depth is different than 100% and SHAPE is changed, the signal freezes at low level of AM Depth value.

If carrier signal is PULSE, instead of any other, then when changing SHAPE or DutyDev in the MOD menu, PWM will stop. Same medicine than above applies to recover...

I was not able to reproduce any part of this bug on firmware v 1.08.

[GonzoTheGreat]

I noticed a fourth bug!

Namely, the SYNC output is not synchronized with the period of the waveform appearing on the OUT output generated with the "Harmonic" menu for certain 3rd order waveforms.

By "not synchronized" I do not mean a constant phase difference.  I mean a variable phase difference between the OUT and SYNCH outputs.  The phase fluctuates wildly - maybe even 100º   

Now, I am trying to figure out for what harmonic amplitudes this bug occurs...

Here we go ...this behavior turns out to be a feature -  not a bug
Below are the steps needed to replicate this behavior:

1) Set the Rigol DG4xxx to factory defaults using the "Preset" button.
2) Enable the Ch1 SYNC output on the front panel using the "Utility" button
3) Enable Ch1 Output
4) Set Ch1 to the Harmonic mode using the "Harmonic" button (Frequency: 100kHz, Amplitude: 5.0Vpp, Offset: 0.0VDC, Start Phase: 0.000º, Order: 2, Type: Even,  SN: 2, Amplitude of the 2nd harmonic: 3Vpp, Phase of the 2nd harmonic: 0.000º)
5) Set your scope to display Ch1 output and SYNC1 output, while triggering on the SYNC1 output.
6) Slowly increase the Amplitude of the 2nd harmonic (shown in green color in pt.4) to 6.0Vpp and observe the loss of synchronization on your scope.

CONCLUSION:  The period of the rectangular signal at the SYNCH1 output is not related to the period of the harmonic waveform on CH1 output, unless you set the CH1 "SyncMode" to "Carrier" using the "Utility" button.

[Tom D]

Thank you for the updates, Gonzo - your time and efforts are much appreciated.

Tom

[OldNeurons]

I received an e-mail from Rigol U.S. one hour ago.
A new firmware is available (00.01.11) and I am waiting for it ...
It is supposed to be fully automated and should take a few minutes according the e-mail.
I followed step by step the procedure and ... nothing yet after more than one hour now. I am not very surprised since previously, I had to ask Rigol US and Germany several times before I got something.

If someone is more lucky than me, please let me know, and share ...

Thanks !!!

Edit : Link to the Rigol Web site
http://beyondmeasure.rigoltech.com/acton/form/1579/0012:d-0001/1/index.htm?id=0012