Rigol HDO1000 and HDO4000 12bit oscilloscopes launched in China

[Veteran68]

I have received the below news from Rigol, see the attached screen capture.

The following link for USA :

https://www.rigolna.com/promos/?utm_campaign=DHO1000%20PROMO%20EMAIL%20-%20032724&utm_medium=email&utm_source=AHA

That's the same $899 the DHO1074 has been selling for since February. Looks like the promotion will extend through July. It's $100 off, but nowhere near the deal that BF was ($400 off).

[vokars]

I am working with the Rigol DHO 1072 for 2 weeks now and it is finally the scope I was looking for many years now. I need it for audio stuff that means low noise, low SFDR, high vertical resolution but not so much bandwidth.

Pros Presale

• Very well specified
• Because many features from the DHO4000 series: very well shielded (information thanks to EEVBLOG teardown) and 1.5 ppm clock precision
• 10 MHz reference input / output
• Averaging and High Res mode in acquisition not just math
• screen resolution 1280×800
• Good visual representation of analog waveforms
• fast and reliable datatransfer for scripting (python / pyvisa)
• Window docking
• pricing ok

Pros from Testing for 2 Weeks now (latest firmware release xxx.12)

• Very good general user experience:
• Really sensitve well shielded instrument with low noise and good SFDR. I finally can see all this mud that my function generator is creating.
• Ergonomic workflow including FFT(!).
• Many small but useful features that make this a great scope e.g. Option windows can be left open during measurement because they can be set to transparent background.
• Low SFDR / noise
• 16 Bit High Res mode @25 MHz bandwidth (with full 2 GSa/s sample rate) !!!
• 14 Bit High Res with 50 MHz bandwidth.
• With the usual bandwith reduction of factor 4 per bit this would be 3.125 MHz not 25 MHz in 16 Bit mode. So it looks like the High Res Filter for 16 Bit doesn't reduce the corner frequency directly but the 14 Bit filter is applied for a second time so that the filter attenuation is larger instead (not sure)?
• Actual good visual representation of analog waveforms as expected.
• 1 MSa FFT works fine. As always the FFT has to be set up approriatly by the user to get the optimal results.
• Remote interface works fine using python scripting / pyvisa. There is one issue: see cons.

Cons from Testing

• Encoders
  
  • in this blog it was reported that encoders sometimes can lose a step. It was speculated if this is a mechanical, software, asic, ... issue: It's mechanical. I have it at the horizontal encoder. But with light side pressure the problem is gone. So it's no showstopper for me but nevertheless Rigol should use other encoders in future versions.
    
  
  
• When measurement is stopped and memory setting is changed then after next measurement the user interface should show the new samplerate. Works with autotrigger but not with single trigger. The refresh is finally triggered when e.g. the horizontal time base is changed. Not a showstopper because just a GUI problem and a workaround exists. When using the remote interface the correct value is provided. But Rigol should fix it with a firmware release.

• XY
  
  • As shown here for the DHO900 33:35 the grid in xy mode is not quadratic. XY is a visual tool so sin/cos with equal amp should be a circle. Nevertheless the scale values are correct but Rigol should change that with a firmware update.

• When getting large waveforms from the scope with scripting/python/pyvisa I need an additional delay of about 200 msec to get the correct waveform. *WAI, *OPC?, *OPC + polling event registers, ... don't provide the required handshaking. Rigol should fix that in a future firmware release.

• FFT cannot use math channels as source. That issue was discussed in this BLOG. It cannot. I understand that this is a performance issue but a slow FFT when using a math channel is better than none at all. Rigol should change that with a firmware release.

Siglent Comparison (SDS1000 HD) (Only Presales no Testing)

• Showstopper for me was that Averaging and High Res ("ERES") is just available as math channels. For audio stuff High Res is the most important mode. And a learned from experience that Rigol has 16 Bit@bandwidth of 25 MHz with smarter filter than just moving average / decimation.
  
  • I heard that for SDS2000 HD series this is planned to be changed with a firmware release but I didn't want to bet on a firmware release for the SDS1000 HD series. When this would be included in a future firmware release it would actually be a game changer.
• Spec not as good as the Rigol DHO 1000 datasheet. E.g. I didn't find the clock precision. My fault?
• SDS1000 HD has lower screen resolution than Rigol DHO 1000 series. Hm ... it's a 12 bit scope ...
• SDS1000 has better math (formula editor, ...) but Rigol math is ok for me because the math channels can be chained (exception FFT ). More complicated stuff has to be done with scripting anyway.

Rigol DHO800 comparison (Only Presales no testing)

• Thanks to the EEVBLOG teardown I have learned that the DHO 800 internal shielding is not what I expect from a sensitive measurement istrument. DHO1000 quite the opposite. Looks rock solid and instrument performance shows that.
• DHO 800 screen too small for a touchscreen with docking windows.

[egonotto]

Hello,

Batronix states “availability unknown (Verfügbarkeit unbekannt)” for the Rigol DHO1074.

Best regards
egonotto

[hololens]

There is an update available:

[Model Supported] All the DHO4000 series oscilloscopes
[Latest Revision Date] 2024/03/27


[Updated Contents]
00.02.13 2024/03/27

      - Fixed the problem of deleting files when copying the same files.
      - Requirements for optimizing the total time for oscilloscope delivery, configuration, and reading.
      - Fixed the problem of crash when LAN is not connected and click Apply.
      - Fixed the problem that after passing the test screenshot, it cannot be stopped.
      - After fixing the default, *IDN? cannot read the project version number.
      - The problem of not closing the project version number lxi/identification.
      - Fixed the issue of statistics not being reset when moving the measurement cursor.
      - Fixed the problem that the measurement value of the moving cursor area is not updated after STOP.
      - Fixed the problem of occasional no waveform when booting.
      - Fixed the issue of the waveform disappearing in small gears after a pause.
      - Implementation of USB external keyboard requirements.
      - Fixed the problem of obtaining Math waveform error.
      - Fixed vertical scaling mask error by testing.
      - Fixed SPI timeout triggering problem, also for four-channel mode.
      - Modify the problem that ultraLab cannot connect to the server after shutting down and restarting.
      - When the Zoom function is turned on, the cursor adjustment area is not limited to the Zoom window.
      - Modify the offset range below 50 ohm and 500uV/div to solve the flip problem.
      - Fixed the problem of failure to modify the settings of measurement source B.
      - Fixed the problem of window transparency and failure to load the last value.
      - Fixed the problem of error in saving screen waveform to csv and SCPI command to obtain waveform in Math filter operation.
      - Fixed the problem of crosstalk caused by adjusting vertical offset.
      - One-click to open the measurement items required by the user and realize the functional requirements of the trigger source tracking channel.
     - Error displayed when modifying the measurement cursor for multi-source measurement.
     - Fix the problem of IIC SCL threshold and SDA threshold random reset&trigger level line random jumping caused by probe ratio at 10X gear.

[sorenkir]

Installed on my DHO1074 without any issue. All options still active. I just had to do the fan speed hack again.
Michel.

[TurboTom]

As @sorenkir reported, installation of the firmware works okay, though not as described in the instructions (Menu -> Storage -> Upgrade -> File Path -> select "Removable USB Disk -> select firmware file (check circle) -> OK -> Upgrade). The "Upgrade" function directly in the main menu (still) doesn't seem to work.

Fan speed mod gets reset as mentioned, moreover the broken "Flattop" FFT window file gets re-installed, so to correct this, the window file needs to be replaced again as described here.

Probe scaling factor appears to be corrected in the decoders, so that's a 

Unfortunately, video trigger still appears to be broken (at least PAL and NTSC, I didn't have a source available for the higher standards).

I'm not certain if someone from Rigol checks this forum for bugs of their products or ideas for improvements -- I rather get the impression that this isn't the case. But I'ld consider it a great idea for Rigol to "give us" the 50 Ohms inputs since Siglent's "Counterpart" (I know some members will argue that comparison...  ) SDS1000X HD comes with them, and some may remember that the DSA800 series of spectrum analyzers all of a sudden got the 10Hz RBW with a firmware update after the SSA3000X appeared on the scene... And come on, repair the FFT windows functions, and what about a temperature-controlled fan? All the required hardware is there already.

Time lacked for more in-depth testing of the new frmware, but as yet it doesn't appear to be a game changer...unfortunately. At least, Rigol is still supporting the series.

[Tom620]

Also upgraded without any problem. Extra options are still there. Had to re-apply the fan-mod.

[Frunse]

Hello, nice to read this,
I am also interested in Audio Elektronics and used the Rigol DS1054Z (Hacked) so far.
For Decoding i have an 34Channel Logic Analyzer https://www.pctestinstruments.com/deutsch/
And the Software is much better to use than on Scops so no MSO Needed.

I was comparing DHO1074 against the SDS1104XHD and ordered me, @ the End, the DHO1074 because of the better Price Performance Ratio on Analogue Representation.

@Saelig
DHO1074                 900$
SDSSDS1104XHD   1399$

DHO1074 Has HDMI Out and better Screen resolution, also the 10MHz Clock Syncronisation capability (SDS1104XHD dont has it @all) becomes Handy with the Sigllent SDG2000X for Syncronisation
(My Eyes will not become better on my Age so i like big Screens )

The only thing i would miss is the BodePlot ability but not for the Cost off Performance.

The Sinalgenerator for SDS1104XHD cost extra Money (165€) so not realy comperable.

The Logic Analyzer kost also additional 342€ for 16 Channel!

The Intronix has 34 Channel and cost 490$ .
Timing-Modus, Sampling-Rate: 1KHz to 500MHz (interne LogicPort Clock)
State-Modus, Sampling-Rate: 0 to 200MHz (Clock-Signal from DUT)
Sample-Puffer: 34 x 2048 Samples (Datakompression: 2^33 to 1 (Sample-Rate up to 200MHz))
Interpreter: see Attachment!



Now i need to wait to get the Sope delivered.

Robert

[TurboTom]

I really like the smooth waveform display on these scopes, especially when playing with memory depth and multiple, overlaying scans, combined with the really good resolution of the display. It's a shame that Siglent apparently didn't do better with their pixel-doubling on the SDS1000XHD. At lest, that's something that Rigol got pretty much right with their entry-level high resolution scopes... 

Definitely a decent choice for audio electronics!

[skander36]

I really like the smooth waveform display on these scopes, especially when playing with memory depth and multiple, overlaying scans, combined with the really good resolution of the display. It's a shame that Siglent apparently didn't do better with their pixel-doubling on the SDS1000XHD. At lest, that's something that Rigol got pretty much right with their entry-level high resolution scopes... 

Definitely a decent choice for audio electronics!

This rubbish called "pixel doubling" by some peoples is a smoothing technique used by all manufacturers(including Rigol on DHO1K) to display a moving wave (pic1). In stop mode where wave is unmoved it is not visible. Not all people zoom on screenshots to search for double/triple /quadruple pixels
The thing that add an unpleasant effect on Siglent scopes (in particular on SDS1KHD) is the stair effect, remembering about 8 bit scopes (pic2). 
For audio electronics I will choose Siglent first, because of it's Bode plot capabilities. It can use two channels to analyze and generate Bode plots simultaneous on both channels on a stereo system (pic3).
That combined with it's easy zoom function to help observing low signals make him the preferred choice for audio.
I have both scopes and I like them both ...

[hpw]

HDO4000 looks for Audio nice ... BUT 

- 2 years old DSO
- FW maintenance cycles a about 6 month

- Only 1M FFT
- Only Flat Top as for 16 bit this is a low performing FFT Window, as may OK for 8..12 Bits
- No dt/d math function as LeCroy & Siglent... and ??
- unknown, white background as using print screen background, as like to print later on. Or to use transparency 0% ??
- 250M to as max 500M memory
- unknown Jitter figures on reference & in case of used external 10MHz reference

Good:

- 100uV/div as lowest scale
- 16uV lowest noise may seen as lowest value on DSO entry market

the question rises, as 2 years old design, any newer DSO in pipeline?

Hp

[zrq]

Note that the possibility to hack a DHO1000 for the 50 Ohm input (only for ranges <=100 mV/div and with some offset issues), all software features on DHO4000 and >500 MHz BW has been proven on my 1074. Although I still couldn't find a perfect solution to the 50 Ohm input that gets me the correct gain for the 200 and 500 mV/div range .

[David Hess]

- 16uV lowest noise may seen as lowest value on DSO entry market

16 microvolts RMS on a 800 MHz 1 megohm input?  Not a chance, and Dave's video showed much higher noise, although not as high as I would have expected.  Dave's video also showed that the ground input coupling selection does not ground the input buffer, so the noise measurement with ground coupling is useless.

Did anybody investigate the noise claim?

[egonotto]

Hello,

Quote from: hpw on Today at 02:47:54 pm:
"- 16uV lowest noise may seen as lowest value on DSO entry market"

As far as I can remember, this was with 20 MHz bandwidth and a 50 Ohm terminator at the input. With a newer firmware the noise is about 22 uV RMS

Best regards
egonotto

[Frunse]

"For audio electronics I will choose Siglent first, because of it's Bode plot capabilities. It can use two channels to analyze and generate Bode plots simultaneous on both channels on a stereo system (pic3)."

This was my only Concern, i wisch i had this on Rigol too but i have an QuantAsylum 403 Analyzer for Audio Spectrum to do great Graphs and FFT.
And for Higher Frequencies I have the little TinySA Ultra but not realy used it much till now.
I am not realy after Radiofrequencies but to watch sometimes the Wlan Channel / Frequencies used, or the Spectrum from an Switched Powersupply (EMV) is a nice Feature

So the Noise and the other Stuff i mentioned before took me to "Dark" Rigol Side also the Possabillity to hack this thing easey

The DS1054Z tooks also long time to get an neare bugfree Firmware so lets look wat Rigol will do in the Future with this Thing "feel the Force Rigol, it will be on youre Side"
The Hardware seems Descend on this Thing only Software seems to be abit behind on some edges.

I will find it out if i got the Scope on Friday

I am an Hobbyist and need to watch my Money so 900$ was much Money for me. And dont want to go higher. \o/

The Rigol 924 and Lower Versions have to little Displays for my Eyes and only 1,25 Gs on one Channel so on 4 Channels not much Left right? like on DS1054Z!

For the Pricepoint i was long time happy with this little Puppy

Robert

[skander36]

Yes, QuantAsylum 403 Analyzer for Audio Spectrum is a better tool for audio than an oscilloscope.

The Rigol 924 and Lower Versions have to little Displays for my Eyes and only 1,25 Gs on one Channel so on 4 Channels not much Left right? like on DS1054Z!

Robert

Indeed for me 7" and 8 bit is a no go from now.

[Frunse]

Got the DHO1000 Scope from Saelig @ Friday.

so far i am happy with it.
Did Firmwareupdate to the newest 00.02.13.00.07

Also the Hack applyied, works realy well.

BW -3dB @330MHz and still @ 500MHz the Signal dont look to bad.
Signal was from TINY SA Ultra 500MHz Sinewave @ 70mvpp.

For an bought 70MHz Scope not bad @ all

For now the only Bug i got was with Web Controll.
The Scope Window change every some Minutes back to Start Window if i changed the Windows size off DHO1000.

May be an Firefox Problem??? Has anyone else the same Problem?? with other Web Browser?
The same Problem with Microsoft EDGE Webbrowser.

Got me also the Noctua 60mm Fans for Silent Upgrade but will do it after some Time Using the Scope.
The orig. are hearable but not realy bad sounding @ all.

2024.07.04
Installed the Noctua 60x25mm 12DC Fan's and now more silence with more Air is moving if i feel it right.
Original only 60x15 Fans.

I am Happy with it

The Probes ar not adequate for the 330MHz -3dB now but i will buy this next Month or so:
Sensepeek 6026 PCBite 2x SQ500 Set

https://www.batronix.com/versand/messtechnik/platinenhalter/sensepeek/6026-PCBite-kit-SQ500.html

With additional 2 SQ500 Probes

Robert

[vokars]

""For audio electronics I will choose Siglent first, because of it's Bode plot capabilities. It can use two channels to analyze and generate Bode plots simultaneous on both channels on a stereo system (pic3)."
This was my only Concern, i wisch i had this on Rigol too but i have an QuantAsylum 403 Analyzer for Audio Spectrum to do great Graphs and FFT. "

Another option that I am using for free for the frequency response / Bode plot is python scripting / pyvisa for that. The remote scpi interface of the Rigol DHO1000 works fine and is well specified. At the moment I am using a sweep, download the 2 measurement channels (channel A direct from the signal generator, channel B from DUT) from the scope, and then FFT the B/A ratio.

But a simple scan via scpi remote interface like that done by all of these embedded Bode plot implementations on other scopes would also be an option. By the way: Siglent Bode's plots seem to be rather slow.

[Frunse]

Hi, thats sounds good and very interesting.
I never worked with Python right now so i need to look into it i guess.

I have an Siglent SDG2042X (Hacked to 120MHz) with LAN and USB, may be this both Devices could worked together with Pyton.
For Bode Plotting.


Found this as an Starting Point

https://www.siglenteu.com/application-note/programming-example-sdg-waveform-creation-with-python-and-sockets-no-visa/
https://www.siglenteu.com/application-note/programming-example-create-a-stair-step-waveform-using-python-and-pyvisa-using-lan/


I know there is on Githup something like this for the older Rigol DS1054Z Oszilloskopes need to look in to that too.

https://github.com/jbtronics/DS1054_BodePlotter

Would be realy nice.

https://github.com/python-control/python-control this seems also for that Kind of using

https://staff.fnwi.uva.nl/r.vandenboomgaard/SP20162017/Python/bodeplots.html

Need to check that.

Again something new i need to learn

Probably the Pythonscript could also easely used on an Raspberry 5 i guess with an touch Display.

[vokars]

"Need to check that."

I am using the toolchain NI Visa + Anaconda + Pyvisa

https://www.ni.com/de/support/downloads/drivers/download.ni-visa.html
https://www.anaconda.com/download
https://pypi.org/project/PyVISA/
https://tw.rigol.com/tw/Images/DHO10004000_ProgrammingGuide_EN_tcm17-5395.pdf

from Anaconda Prompt type: jupyter notebook
That starts the jupyter server and opens a navigation page in the web browser. There you can load existing or create new notebooks. A notebook has cells that can include python code. With shift + enter the code can be executed.

typical start is:

import pyvisa
import matplotlib.pyplot as plt
rm = pyvisa.ResourceManager()
print(rm)
print(rm.list_resources())
scope=rm.open_resource(<your scope visa id string>)
scope.read_termination = '\n'
print(scope.query('*IDN?'))

Now you can query the scope using SCPI command strings as described in the Rigol Programming Guide.
Note that for query waveforms in raw mode the auto trigger must be stopped first. To check, wether the scope actually has stopped, you can poll with :TRIGger:STATus?

[Frunse]

Very Nice and thanks alot

I will try it by sure.

Robert

Installed all.
But already the first Command don't Work

import pyvisa

---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
Cell In[4], line 1
----> 1 import pyvisa

ModuleNotFoundError: No module named 'pyvisa'

Also tried this:
import PyVISA

Same Error:

Not sure why
I am Installed all on C: with the Default Values the Installation Rutine gave me....

Installed Python 3 than Anaconda and as last NI_VISA all on C:
Jupiter starts and i open an Notebook session but it wont't work

So not sure whats going on

Also this way i Checked it:

(base) C:\WINDOWS\system32>py -m pip install --upgrade pip setuptools wheel
Requirement already satisfied: pip in c:\users\frunse\appdata\local\programs\python\python312\lib\site-packages (24.1.2)
Requirement already satisfied: setuptools in c:\users\frunse\appdata\local\programs\python\python312\lib\site-packages (70.3.0)
Requirement already satisfied: wheel in c:\users\frunse\appdata\local\programs\python\python312\lib\site-packages (0.43.0)

(base) C:\WINDOWS\system32>py -m pip install PyVISA
Requirement already satisfied: PyVISA in c:\users\frunse\appdata\local\programs\python\python312\lib\site-packages (1.14.1)
Requirement already satisfied: typing-extensions in c:\users\frunse\appdata\local\programs\python\python312\lib\site-packages (from PyVISA) (4.12.2)

(base) C:\WINDOWS\system32>


May be something is wrong with the PATH Variable on Windows

Found Help need to instal pyvisa this way on Conda Shell:

conda install -c conda-forge pyvisa

Now it looks like this but something didn't work also no massages whats going on here??? See attached picture.

Anaconda Shell tells that!!!

[I 2024-07-11 13:32:00.389 ServerApp] Connecting to kernel d89653e5-2b7f-4a61-a3fc-ac3fdfc1d611.
[I 2024-07-11 13:32:00.389 ServerApp] Restoring connection for d89653e5-2b7f-4a61-a3fc-ac3fdfc1d611:70119777-695e-4c42-bc23-ee2fd58194cb
0.00s - Debugger warning: It seems that frozen modules are being used, which may
0.00s - make the debugger miss breakpoints. Please pass -Xfrozen_modules=off
0.00s - to python to disable frozen modules.
0.00s - Note: Debugging will proceed. Set PYDEVD_DISABLE_FILE_VALIDATION=1 to disable this validation.

It seems realy slow here now i gott all Informations and it works like suggested!

So Kommunication with Generator works also

generator=rm.open_resource('TCPIP0::192.168.0.103::INSTR')
generator.read_termination = '\n'
print(generator.query('*IDN?'))

Got this:
Siglent Technologies,SDG2122X,0123456789,2.01.01.38R4

If i am right i need to do this next:

Commands for Generator to start an sweep between Start and Stop Frequencies with @ specified Voltage 
Commands for Scope to get the recordet Values from SCOPE ADC after DUT (Filter or anything like this) on specified Channel (Triggering ?)
Commands to Plot an Graph from transfered Values.

Easy ....LOL ....NOT Realy

Colected some Commands that works so far with my Generator as Example:
Preparation for Sweeping Wave:

generator.write('C1:SWWV STATE,ON')
generator.write('C1:SWWV TIME,30S')
generator.write('C1:SWWV STOP,20000HZ')
generator.write('C1:SWWV START,20HZ')
generator.write('C1:SWWV CARR,AMP,0.5V')
generator.write('C1:SWWV CARR,OFST,0.1V')
generator.write('C1:SWWV CARR,PHSE,20')
generator.write('C1:SWWV STATE,OFF')

Output Aktivation Settings:

generator.write('C1:OUTP LOAD,50')
generator.write('C1:OUTP ON')
generator.write('C1:OUTP OFF')

Bassis Wave Command:

generator.write('C1:BSWV MAX_OUTPUT_AMP,2')

More next days

Robert

[zrq]

Noise of a hacked DHO1000 (actual bandwith conservatively estimated to be >500 MHz) with input terminated with 50Ohm. Note that in the one with 500 uV/div, the scope seems to apply a 250 MHz bandwidth limit which can not be disabled.
And DSOX3034T at work for comparsion (forgot turning off 50 Ohm though).

[vokars]

"More next days"

I have created a simple Bode Plot script blueprint. Is a starting point and can be modified for personal needs:

# Script Initialization
import pyvisa, time, math
import numpy as np
import matplotlib.animation as animation
%matplotlib inline
#%matplotlib notebook
import matplotlib.pyplot as plt
rm = pyvisa.ResourceManager()
print(rm)

fg=rm.open_resource(<Your function generator VISA string here>)
fg.read_termination = '\n' # See programming manual for your function generator
print(fg.query('*IDN?'))

scope=rm.open_resource(<Your scope VISA string here>)
scope.read_termination = '\n'
print(scope.query('*IDN?'))


# Bodeplot Scan Method

# Only 1 channel. Final version should use a ref channel from the function generator without DUT and substract the log amp.
# If you wanna see the progress live, use Python animation framework
# For test run without DUT but just 1 channel function generator uncomment the function generator amp model creation

# ********** Config ***********
gl_points_per_decade = 2.0
gl_decade_start_log = 2 # Min 2, otherwise Autoset unstable
gl_decade_stop_log = 7.2
y_axis_is_dB = False # choose between dB or vpp y axis scaling here
# *****************************

lc_f_log = gl_decade_start_log
f_log_list = []
dB_list = []
vpp_list = []

scope.timeout = 5000
fg.timeout = 5000
scope.write("*WAI;:MEASure:ITEM VPP,CHANnel1")
scope.write("*WAI;:MEASure:STATistic:RESet")

# Loop: Set function generator frequency and measure amp with scope
while lc_f_log <= gl_decade_stop_log:
    lc_f_Hz = pow(10.0, lc_f_log)
   
    # function generator set frequency
    lc_str = "SOURce1:FREQuency " + str(lc_f_Hz) # for AFG 30022B; exchange if other function generator
    fg.write(lc_str)
    # time.sleep(1.0) # Settlement Time for function generator
    fg.query("*OPC?")
   
    """
    # Only Test
    # Function Generator emulates DUT, use comments for real DUT
    lc_amp = 5.0/lc_f_log # Model
    #lc_amp = 5.0 * (gl_decade_stop_log + 0.5 - lc_f_log) / (gl_decade_stop_log - gl_decade_start_log)
    lc_str = str(lc_amp)
    #print(str(round(lc_amp,2)))
    lc_str = "SOURce1:VOLTage:LEVel:IMMediate:AMPLitude " + lc_str
    fg.write(lc_str)
    #time.sleep(1.0) # Settlement Time for function generator
    fg.query("*OPC?")
    """

    scope.write(":AUToset")
    # scope.query("*OPC?") # Not working: ToDo Rigol Firmware Update
    time.sleep(3.0) # Workaround that wastes time. Would be better to query if Autoset is ready. Change value if read errors occur

    # scope measure amp
    # ToDo: Average instead of current value for higher precision. In this case increase sleep for settlement
    lc_vpp = float( (scope.query(":MEASure:STATistic:ITEM? CURR,VPP,CHANnel1")).strip() )
    # store log f
    if lc_vpp < 1E3: # check for read errors
        f_log_list.append(lc_f_log)
        vpp_list.append(lc_vpp)
        dB_list.append(20.0 * math.log10(lc_vpp))
        print("*", end="")
    else:
        print("!", end="")
    lc_f_log += 1.0/gl_points_per_decade

# Show result
print()
plt.title("Bode Plot", fontsize=14, pad=12)
plt.xlabel("log(f) / log Hz")
plt.grid()
if y_axis_is_dB:
    plt.ylabel("dB Vpp") # With second Ref channel this becomes real frequency dependend attenuation
    plt.plot(f_log_list, dB_list)
else:
    plt.ylabel("Vpp / V") 
    plt.plot(f_log_list, vpp_list)
plt.show()