Rigol DHO804 Bode Plot

[Mechatrommer]

my prototype now can be used with DHO804 for bode plot (barely) so i tried to redo test by TimFox here...
https://www.eevblog.com/forum/testgear/rigol-dho914s-bode-plot

R = 100 ohm, C = 33nF, so cutoff freq = 48kHz... (1 / (2.pi.R.C) )
i can confirm the same bugs and wobbly effect in old FW1.14.

1) the bode plot procedure is finding optimum vertical scale for each frequency, but its inefficient imho. its just brute force set to minimum vertical scale and increase the scale until signal fits the monitor for each point. this results one click for each channel for every point to be plotted (2 clicks per point), i think this can wear out front end relay quickly. the more efficient way is only do brute force search during the beginning, and increase or decrease vertical scale from there on the next point, if signal too small, decrease scale, if signal too big, increase scale, cant you think of that rigol? how many brains you have over there?

2) i tried to set acquisition to average to reduce noise and hopefully wobbly effect of the plot on low level signal, but unfortunately the dso changes to normal acquisition during bode plotting, sigh. where is another brain?

3) suggestion: another trick to get better bode plot. is to convert input signal to FFT, find largest magnitude bin, that is our fundemantel, get it phase as well. then convert the output signal (CH2) to FFT, and find the same bin element, find its magnitude and phase, substract both values and you got a point on bode plot. i think this will be much cleaner.

so i guess if bode plot is too important, controlling DHO804 from PC to adjust time and vertical scale appropriately, command the AFG to give incremental frequency at desired voltage level, download the data to PC,and do our own procedure/algorithm for bode plot is much preferable... only the good thing about internal AFG/AWG is we only need one cable connected to PC rather than two in case of external AFG unit... fwiw...

[Randy222]

If 100,000 owners of a DHO email Rigol saying "it would be good if you could write the code needed to run a functional BODE plot, that would be good since your competotors like Siglent already do it", maybe Rigol will do it.

Maybe you get a reply like, "yes, our new DHO Pro series will have BODE". 

[Mechatrommer]

they already did, except we need to email them telling "your bode plot function is not efficient enough yet, let us help you with suggestions"

[Randy222]

BODE is in DHO800 firmware 01.00, 01.01, and 01.02 ?
I was not aware.

[Mechatrommer]

BODE is in DHO800 firmware 01.00, 01.01, and 01.02 ?
I was not aware.

i guess yes, but there is channels offset issue after calibration, so nobody use that with 924S vendor.bin... further investigation/hack will be needed on that.

[Fungus]

BODE is in DHO800 firmware 01.00, 01.01, and 01.02 ?
I was not aware.

You have to enable the AWG functions for it to appear (ie. change model to DHO900S).

[vanyas]

But no offset with DHO914/DHO914S vendor.bin

Waiting for your AWG module...

[Mechatrommer]

But no offset with DHO914/DHO914S vendor.bin

do you know the link for DHO914S vendor.bin? i'm not aware of it... what i saw from people is DHO914 vendor.bin (no AFG option)

[Pinkus]

As far as I understand this:
https://www.eevblog.com/forum/testgear/hacking-the-rigol-dho800900-scope/msg5223060/#msg5223060
you can create your own by using the software from the link.
"DHO924S" as the scope model should do it (I did not try this yet).

[vanyas]

But no offset with DHO914/DHO914S vendor.bin

do you know the link for DHO914S vendor.bin? i'm not aware of it... what i saw from people is DHO914 vendor.bin (no AFG option)

You can use this tool to change model in your vendor.bin https://github.com/zelea2/rigol_vendor_bin saving your S/N and MAC

[Randy222]

But no offset with DHO914/DHO914S vendor.bin

do you know the link for DHO914S vendor.bin? i'm not aware of it... what i saw from people is DHO914 vendor.bin (no AFG option)

You can use this tool to change model in your vendor.bin https://github.com/zelea2/rigol_vendor_bin saving your S/N and MAC

SecureAge and BkavPro always seem to red flag these github files.

[Pinkus]

Bkav Pro is known to produce a lot of false positives.
The products of the other 70 virus vendors (checked at https://www.virustotal.com/) did not find any problem, thus I am confident, that SecureAge is wrong too.

[Fungus]

Here's a DHO914 vendor.bin

[Mechatrommer]

Here's a DHO914 vendor.bin

cannot do bode plot

[Randy222]

Bkav Pro is known to produce a lot of false positives.
The products of the other 70 virus vendors (checked at https://www.virustotal.com/) did not find any problem, thus I am confident, that SecureAge is wrong too.

Or perhaps the other 70 have literally missed it. 
VT makes no claims to the accuracy of the tools they list.

[vanyas]

DHO914S vendor.bin

[Mechatrommer]

My Second Bode Plot on DHO804 (AFG module rev 2) with latest FW 1.2.2



bode plot function is improved on latest FW as if they listened to my point #1 in OP last time i tested on much older FW 1.14 btw will do AFG module rev 3 to improve further noise level, if not by a lot...  i hope that will be the last revision before i publish it cheers.

attached are my prototype replica board, just in case if someone want to have a sneak peek fwiw...