Author Topic: New Rigol 16-bit function generators DG800/900 series  (Read 92749 times)

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Offline maxwell3e10

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #175 on: May 20, 2019, 02:52:41 am »
HOW TO CHANGE RIGOL DG800/DG900 MODELS

1. Get a blank formatted USB disk (capacity >= 1GB)

2. Write signature in the disk with the following command (in linux):

        sudo dd if=DG800_sardinha.bin of=/dev/sda1 bs=512 seek=2000000


This sounds great! Does anyone know how to do this on Windows? What file system should the USB be formatted to? What is the equivalent signature command?
 

Offline bitseeker

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #176 on: May 20, 2019, 04:34:17 am »
Here's a good place to start: https://www.google.com/search?q=dd+for+windows

I haven't tried dd on non-Linux platforms, but if one of them supports all the parameters, it should work.
TEA is the way.
 

Offline timber23

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #177 on: May 20, 2019, 06:15:28 am »
HOW TO CHANGE RIGOL DG800/DG900 MODELS

1. Get a blank formatted USB disk (capacity >= 1GB)

2. Write signature in the disk with the following command (in linux):

        sudo dd if=DG800_sardinha.bin of=/dev/sda1 bs=512 seek=2000000


This sounds great! Does anyone know how to do this on Windows? What file system should the USB be formatted to? What is the equivalent signature command?
I used a virtual machine (VMware) with Xubuntu installed. VMware player or VirtualBox are free software and the procedure works. Inside a VM you won't do any damage to your system, if you use dd command wrong. Installation is nowadays straight forward. Opening a terminal should be easy. Finding the correct device path to USB drive is also easy, when knowing the command, e.g. "lsblk" or maybe "sudo lsblk". Knowing the correct path leads to the dd command introduced by tv84. That's it.
 

Online TurboTom

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #178 on: May 20, 2019, 07:26:25 am »
Since I also didn't have a Linux machine available (my Linux netbook silently vanished in my epic mess...too many projects at a time...and I was too lazy to wire up a Raspi) I used a free disc editor (HxD) to manually enter the eight "magic" bytes at the beginning of sector 2000000 of the thumb drive. Worked a treat.

Regarding the performance of a "pimped" DG811, it clearly doesn't match the specs of a DG9xx. The latter is specified with an amplitude accuracy of +-1dB above 40MHz and we're consitently seeing close to -3dB @ 100MHz on the modified DG8xx's. We've got to figure out how the calibration of the DG9xx is supposed to work to finally be able to tell if there's a hardware difference -- maybe actually the DG8xx series utilizes a different output opamp than the DG9xx series since two of the THS3091 that I'ld expect there would add considerably to the BOM...
« Last Edit: May 20, 2019, 07:27:56 am by TurboTom »
 
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Offline bitseeker

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #179 on: May 20, 2019, 08:14:56 am »
Since I also didn't have a Linux machine available (my Linux netbook silently vanished in my epic mess...too many projects at a time...and I was too lazy to wire up a Raspi) I used a free disc editor (HxD) to manually enter the eight "magic" bytes at the beginning of sector 2000000 of the thumb drive. Worked a treat.

Cool :-+
TEA is the way.
 

Offline timber23

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #180 on: May 20, 2019, 08:37:32 am »
Since I also didn't have a Linux machine available (my Linux netbook silently vanished in my epic mess...too many projects at a time...and I was too lazy to wire up a Raspi) I used a free disc editor (HxD) to manually enter the eight "magic" bytes at the beginning of sector 2000000 of the thumb drive. Worked a treat.

Regarding the performance of a "pimped" DG811, it clearly doesn't match the specs of a DG9xx. The latter is specified with an amplitude accuracy of +-1dB above 40MHz and we're consitently seeing close to -3dB @ 100MHz on the modified DG8xx's. We've got to figure out how the calibration of the DG9xx is supposed to work to finally be able to tell if there's a hardware difference -- maybe actually the DG8xx series utilizes a different output opamp than the DG9xx series since two of the THS3091 that I'ld expect there would add considerably to the BOM...
Your approach, using HexEditor, is much better than mine if someone has no Linux available. Thanks for sharing.

Did you spot any parts on the PCB which could cause this ~ -3dB attenuation?

Maybe the user with his DG952 could upgrade to DG992 and check if his amplitude at 100 MHz is within +/- 1dB ?
 

Offline idolclub

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #181 on: May 20, 2019, 09:03:04 am »
Here's a good place to start: https://www.google.com/search?q=dd+for+windows

I haven't tried dd on non-Linux platforms, but if one of them supports all the parameters, it should work.
There is no need to install linux, just download Ubuntu Linux ISO and running Ubuntu directly from either a USB stick or a DVD.
« Last Edit: May 20, 2019, 02:39:24 pm by idolclub »
 

Online TurboTom

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #182 on: May 20, 2019, 11:36:31 am »
After another, more thorough reading of the DG900 performance verification guide, it appears that the "improved" DG8xx may actually match the requirements of the DG992!

First of all, the performance specs list the amplitude accuracy as "typical" which basically means you can forget all the number that follow...  :o

Then, the verification procedure of the amplitude accuracy asks just for a test at 50MHz as the highest frequency where the output amplitude has to be +-1dB accurate -- which shouldn't be a problem for a modified DG8xx.

---------

Just did it correctly and pulled my 437B / 8482A power meter out to do the amplitude accuracy test "the proper way". At the specified test frequencies for the DG992, my "DG811+++" performs better than within one tenth of the permitted error margins on both channels. I further tested for the frequency of 1dB amplitude drop, which were 81MHz and 85MHz for channels 1 and 2. At 100MHz I measured a drop of 2.16dB and 1.83dB, respectively.

So we may actually be up to a surprise if we'ld get a chance to test a "real" DG992...  >:D
 

Offline Zack

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #183 on: May 20, 2019, 02:43:23 pm »
maybe actually the DG8xx series utilizes a different output opamp than the DG9xx

The Motherboard part numbers 2010004229 in the the DG800 and DG900 are identical, comparing the Service Guides.

https://www.rigol.com/File/TechDoc/20190213/DG800_ServiceGuide_CN.pdf
https://www.rigol.com/File/TechDoc/20190213/DG900_ServiceGuide_CN.pdf
 
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Online TurboTom

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #184 on: May 20, 2019, 05:20:43 pm »
@Zack -

welcome to the forum and great finding! This should actually wipe away all my (our?) concerns regarding differences between DG800 and DG900 series, the hardware is identical and hence the performace should be the same after the upgrade. I'm curious if there's a calibration guide available on the chinese site already?

During my tests of the "DG811+++" I found a few peculiarities:

It's good to see that parameter changes (frequency) of sine output takes place without any glitches. Square and Pulse waveforms provide (almost) glitch-free parameter changes (frequency, symmetry/pulse width, slope) up to frequencies of 1MHz, above that, the signal pauses for a few milliseconds at half the signal level (i.e.[Vmax+Vmin]/2).
The "almost" mentioned above means that once in a while I was able to catch a strange high frequency glitch of several superimposed frequencies when changing the frequency setting, see attached screenshots.
Ramp and Arb waveforms always pause for a few milliseconds upon parameter changes.

Amplitude changes only cause glitches if the internal attenuators switch ranges. Yet, this happens rather often. I found such switching events (50 Ohms output impedance selected, for high-impedance, double the specified figures) to take place at 2.5mV, 6.4mV, 16mV, 40mV, 100mV, 256mV, 640mV*, 1.6V and 4V. It's quite peculiar that the 640mV switching event takes place without an audible relay click. If a glitch-free level sweep is required, the output signal can be amplitude modulated by an internal ramp.

I also did the "PAL raster frequency test" (outputting two ramps of 50Hz and 15625Hz and observing the relative phase) that my SDG6000X failed at and found the "DG811+++" to fail as well. The phase should stay constant, i.e. the frequencies should stay locked against each other, but I find them to walk through at very slow pace in an incremental manner, see the third and fourth screen shot. They can be brought back to the original relation by pressing the "Align" button.

Considering the price of the "unimproved" instrument  ;), these small problems may be tolerable, especially since they are really of minor importance for the average user.

Btw, the very nice touch screen is extremely well integrated into the UI concept, it's obvious that the whole UI had been designed with the touch panel in mind instead of other manufactures' approaches where it's plain to see that a touch panel had been added to an existing firmware package and it more or less only duplicates functions that can be accessed via the key pad as well.

Cheers,
Tom


P.S. Just for fun I aded a fifth screen shot where I compared the rise times of the edges in Pulse mode between the "DG811+++"  and my "SDG6000X-I" ("I" =  improved...must be chosing the equipment upon the possibility to hack...  >:D) Hint: The measured rise time of the SDG is rather limited by the scope used than by the generator!
« Last Edit: May 20, 2019, 07:03:37 pm by TurboTom »
 
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Offline maxwell3e10

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #185 on: May 20, 2019, 05:49:51 pm »
@TurboTom -thanks for digging into it. I already ordered one.  It will be fun to compare against Keysight 33522.
 

Offline timber23

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #186 on: May 21, 2019, 12:57:15 am »
I did not find any remote control software for DG800/900. Because I wanted to control the device from PC, I wrote a small Python script.
I used Python 3.7 with PyQt5 and PyVISA. If you do not have it: After installing Python3 you can install PyQt5 with "pip install PyQt5" and PyVISA with "pip install pyvisa"
The GUI is made using Qt Designer.

To change a value type it in and press [enter].

Execute from command line with all three files in same folder: "python myDG800.py"

The script is "work in progress". Maybe it is of some use for anybody...
 
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Offline bitseeker

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #187 on: May 21, 2019, 01:04:43 am »
Looks cool, timber. Thanks for using Python 3.
TEA is the way.
 

Offline timber23

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #188 on: May 21, 2019, 02:56:01 pm »
I have the opportunity to do some measurements with a real DG992. It seems that at least at the top end of the frequency range, the real one is better.

I did an initial comparison. If you have special requests, let me know. But I am not allowed to open the device.

Please note that I used the same cable for all the tests. The second cable in the photo above let to misleading results.

Somehow the pimped DG811's signal is a little bit attenuatet (-2.2 dBm) at 100MHz.

Best regards
Timber

 
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Online tv84

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #189 on: May 21, 2019, 03:23:42 pm »
timber,

Convert the 992 to 811 and do the same tests.
 

Online TurboTom

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #190 on: May 21, 2019, 05:01:48 pm »
@timber23 --
Great that you had the opportunity to test a genuine DG992, and thanks a lot for the info.
Since we know that the hardware of the DG800 and DG900 series is identical, I'ld assume that it's all about a different calibration of the two flavors.
This means one way or the other we've got to get hold of the calibration instructions...

Cheers,
Thomas
 

Offline Kosmic

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #191 on: May 21, 2019, 05:37:09 pm »
Another possibility is that they test the boards after production and sort them by performance. The good performer goes for the DG992 and the average for the other models.
 

Offline frozenfrogz

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #192 on: May 21, 2019, 07:06:08 pm »
Another possibility is that they test the boards after production and sort them by performance. The good performer goes for the DG992 and the average for the other models.

That was exactly my guess.
He’s like a trained ape. Without the training.
 

Offline bitseeker

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #193 on: May 21, 2019, 07:23:22 pm »
It's possible that they bin the final boards by performance, but it may simply be that the calibration just isn't performed at frequencies above their model designation.

Being able to recalibrate the generators would take care of either case. So, that would be the important next endeavor.
TEA is the way.
 

Online tv84

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #194 on: May 21, 2019, 07:50:17 pm »
I bet on calibration. That's why I asked timber to convert the 992 in a 811/812 and do some tests.
 

Online 2N3055

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #195 on: May 21, 2019, 08:35:23 pm »
With today process control and components, I would be surprised if there was any significant spread in specs across batches. Any spread is calculated in into parameter calibration range. They save money calibrating amplitude for smaller bandwidth.
Short version: I also highly doubt there is binning, only partial calibration. Binning actually cost money, they would avoid it, leaving only shorter calibration as a savings on lesser models..
 
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Offline Kosmic

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #196 on: May 21, 2019, 08:46:49 pm »
With today process control and components, I would be surprised if there was any significant spread in specs across batches. Any spread is calculated in into parameter calibration range. They save money calibrating amplitude for smaller bandwidth.
Short version: I also highly doubt there is binning, only partial calibration. Binning actually cost money, they would avoid it, leaving only shorter calibration as a savings on lesser models..

Make sense.
 

Offline thm_w

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #197 on: May 21, 2019, 09:21:12 pm »
Processor: https://www.ti.com/product/AM3352

That is a nice processor board, price seems not bad for TI, $6 for 1GHz A8.
J1 connector seems to just be to prevent you from plugging it in backwards! The connections don't go anywhere. There is a very small risk though of that board falling out, if there is excessive shock during transportation.

Ram (2pc): https://www.micron.com/products/dram/ddr3-sdram/part-catalog/mt41k128m16jt-125-it
DDR3-1600 256MB ~$8

Relay (12pc): http://www.hongfa.com/product/detail/70689a00-9d73-4802-b0ac-e36561332f57
HFD4/4.5-S <$1 ea

DAC (if its the one reported above): https://www.analog.com/en/products/ad9747.html#product-overview
AD9747 Dual 16-Bit 250 MSPS $16
AD9743/AD9745/AD9746 are reported as lower bit rate (10, 12, 14-bit) so probably cannot be swapped in, but who knows? They could still be using the same die.
« Last Edit: May 21, 2019, 09:26:25 pm by thm_w »
 

Offline timber23

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #198 on: May 22, 2019, 12:45:11 am »
I conducted the following test:
First DG922 connected to Rigol MSO5000 via BNC and 50ohm termination.
I put DG922 in all possible modes using channel 1.
I measured every 100 KHz Vpp starting at 1 MHz up to maximum frequency using SCPI commands (one command to set freq. and one for measuring).
After finishing all modes for DG922 I disconnected the BNC cable from DG922 and connected it to DG811. After that I performed the same measurements for all modes again.

All measurements were added to an excel sheet (see file attached).

This is how the plot of the data looks like. Until 55MHz the results are very similar. After that there is a difference between DG992 and DG811, independed of the mode set.
 
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Offline frozenfrogz

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Re: New Rigol 16-bit function generators DG800/900 series
« Reply #199 on: May 22, 2019, 12:58:51 am »
Until 55MHz the results are very similar. After that there is a difference between DG992 and DG811, independent of the mode set.

That looks about what I am seeing on my hax0red DG812 (though I do not have that sophisticated kind of gear to really verify).

Thank you for going through all the effort! :)  :-/O


Edit: There is no calibration manual available yet for either DG800 or DG900 series, but as these are available for more or less the rest of the line-up it might be just a matter of time to see it pop up here:

https://www.rigol.eu/calibration/
« Last Edit: May 22, 2019, 01:02:53 am by frozenfrogz »
He’s like a trained ape. Without the training.
 
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