Same result with different integration time about python-seabreeze HOT 20 CLOSED

What happens if you use an integration time of one second instead of 100 micro-seconds?

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Thank you for your reply. I did try different integration time, 1000, 2000... I also cover and uncover the sensor head. The result is not the same but always very similar result. I plotted the result, the shape of the spectrum is very similar and the range of the values is very similar.

from python-seabreeze.

try setting your trigger mode to free running and take several spectra, if that wont work, report to oceanoptics.

spec.trigger_mode(2)
spec.integration_time_micros(100000)
for i in range(10):
    intensities = spec.intensities(correct_dark_counts=False, correct_nonlinearity=True)
print intensities

from python-seabreeze.

Thank you for the suggestions. I changed the trigger mode to 2 then I have the following error messages:
Traceback (most recent call last):
File "saveSpectrum2File_.py", line 18, in
Intensities = spec.intensities(correct_dark_counts=False, correct_nonlinearity=True)
File "/usr/local/lib/python2.7/dist-packages/seabreeze/spectrometers.py", line 149, in intensities
out[transfered_N:])
File "seabreeze/cseabreeze/wrapper.pyx", line 209, in seabreeze.cseabreeze.wrapper.spectrometer_get_formatted_spectrum (./seabreeze/cseabreeze/wrapper.c:5729)
seabreeze.cseabreeze.wrapper.SeaBreezeError: Error: Data transfer error

Normally I connect the spectrometer to USB, a led light on the spectrometer is on. When I use trigger_mode(2) or trigger_mode(1), the script freeze and the led light is off. If I unplug the USB cable from the spectrometer, I have the above error messages.
Any suggestions on this?

I also tried trigger_mode(0) with a loop to get the last reading from a series of readings. If I cap the sensor head, the dark reading is very high (compared to the dark reading I got from OceanView, 1500 compared to 50). If I remove the cap, the reading is reasonable. Very strange behavior.

from python-seabreeze.

It's very hard to debug from here. I would recommend you'll try the following things:

• get the python module to work on the same machine you run OceanView
• try disabling the nonlinearity correction
• try not setting the trigger mode at all (then it should default, to probably 0 in your case)
• try both backends. cseabreeze and pyseabreeze.

Good luck :)

from python-seabreeze.

Thank you very much for your suggestions. I will update my findings if you have any progress.

from python-seabreeze.

Closing this for now. Please reopen if this is still an issue.

from python-seabreeze.

I am experiencing similar issues. If I get and plot the spectrum with 1 s acquisition time, then change the time to 10 s and measure again (like shown below) i am going to get the result immediately (not blocking for 10 s) and the result would look exactly as for 1 s. If i repeat the measurement again I will be getting proper 10 s measurement.:

spec.integration_time_micros(1e6)  
plot(spec.intensities())
spec.integration_time_micros(1e7)
plot(spec.intensities())

I believe this is due to the fact that the spectrometer is in free-running mode and returns the previous measurement when the 10 s measurement is still running. It does not work for me, as I need to measure spectra in a loop and make sure that the acquisition starts exactly at the beginning each iteration and not before. Therefore I tried to do spec.trigger_mode(1), which according to seabreeze docs it the "software-controlled" trigger mode, but if i try to measure in this mode the code freezes exactly as stated above. I wonder if it is waiting to receive a trigger signal and if there is a specific way to send it.

I tried both backends and do not see any difference in behaviour.
Also I am experiencing similar dark count values of approximately 1500 counts, however I did not check what are the dark counts values in OceanView. I am not using dark count or nonlinearity corrections. And I checked that spec.trigger_mode(0) is actually the default one.

I will be very grateful if you could help me with this,

Thanks,
Anton

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Hi Anton, you forgot to mention your spectrometer model. Best, Andreas

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Hi Andreas,
Yes i did, and thanks to you pointing this out I actually looked trough the spectrometer datasheet. The spectrometer model is QEPro and it seems (according to the datasheet https://oceanoptics.com/wp-content/uploads/OEM-Data-Sheet-QEPRO.pdf) that it actually does not have the software-controlled trigger mode, so free-running is all I get. It seems that the only way to achieve the desired behaviour is to:

1. Send Abort Acquisition message to put the spectrometer into Idle Mode
2. Set it to free running mode at the beginning if each iteration with spec.trigger_mode(0)
3. Clear all buffered spectra (Perhaps with the implementation of sbapi_data_buffer_clear method)
4. Take the spectrum
5. Send Abort Acquisition message again

Do you agree with this findings? And are the "Abort Acquisition" and "Clear buffer" methods implemented in the python library?

Thanks,
Anton

from python-seabreeze.

Hi Anton, I think it's worth a try.

The commands are not exposed via the wrapper, but you can implement them quite easily if you use the pyseabreeze backend.

If you look at issue #37 you'll see an example of how to send the obp commands to the spectrometer.

Let me know how things go, and if you need further help, open a new issue for this.

Best
Andreas

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Hi Andreas,
I actually already wrapped the libseabreeze 'sbapi_data_buffer_clear' method in similar manner you did for others and it seems to work. Also I found that the fork mentioned in pull request has the 'spec.write_usb' method already implemented and it also works. I may look into pyseabreze backend at some point, thanks for the example, but now I seem to have everything I need.

You may also be interested in knowing that this was built on Windows 10, with the latest official libraries from sourceforge.

Best,
Anton

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Cool!
Feel free to make a pull request.
When I have more time I'll start merging new features.

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hello! I'm experiencing the same issues as @lancaster17. Did you push your update? If not how could I get this working? I'm a hardware guy. Thank you very much!!

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I am using c++ wrapper classes to control QE pro. And I just met same problem.I find a way to solve it.
1.set the buffer to minimu size 1.
{
long test = seabreeze_get_buffer_capacity_minimum(m_iSpectralmeterHandle, &error);
seabreeze_set_buffer_capacity(m_iSpectralmeterHandle, &error, test);
}
2.call function to clear buffer before readout data.
{
seabreeze_clear_buffer(m_iSpectralmeterHandle, &error);
flag = seabreeze_get_formatted_spectrum(m_iSpectralmeterHandle, &error, spectrum, spec_length);
}

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@XiaomingY @ap--
Can you reopen this issue ?

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Hi @PyMarc2

I recommend opening a new issue for your specific problem.
It's best to include as much information as possible to make it easy to help.
Example code and stack traces of the error are extremely helpful as well as information regarding you spectrometermodel, your operating system etc.

Cheers,
Andreas 😃

from python-seabreeze.

from python-seabreeze.

Hello, I am having the same problem with QE Pro spectrometer as I want to start measurement at exact time, controlled by software.

I've read in this issue that QE Pro doesn't have a software trigger, however, the User manual explicitly states that software trigger is supported: https://www.oceaninsight.com/globalassets/catalog-blocks-and-images/manual--instruction-re-branded/spectrometers/ocean-qe-pro_manual.pdf (p 15). Is the manual wrong on this? Does anyone know is they've added this functionality since?

Anyway, it seems some people have solution to this problem, @lancaster17, @zzwyrmslayer , could you say whether you achieved the result with pyseabreeze or cseabreeze?

By the way, link to datasheet some posts ago is dead, and I cannot find any updated datasheet on the official website.

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For future reference, here is my solution for adding "stop acquisition" and "clear buffers" functionality. There were some hacky steps needed because of library architecture.

https://gist.github.com/positron96/42107b3a8d5d1aa4a92514665cc46dbb

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