Error code 6 when trying to convert LI file

I’m trying to run this example to have a python script grab some data and save it to file. However, when I try and convert the saved .li file to any other format, using either the GUI converter or mokucli, I get “Error code 6” and the conversion fails. moku.__version__ yields 3.0.0 and the last firmware update I did was for fw_ver=576. Is this user error on my part? The only line I changed in the example file is the IP address of my specific device.

Hi @gautam, thank you for reporting this issue.

Can share the log file with us please to have a look at where the issue originated from. Can you please email the file to

Thank you!

Thanks Nandi for looking into this, I’ve emailed the file.

Hi Gautam,

Thank you for sending through the file.

There is a bug in our Data Logger example, you will need to replace line 46, i.e. the file download command, with the following:"persist", logFile['file_name'], os.path.join(os.getcwd(), logFile['file_name']))

We are working on updating the example script on our documentation page now, thank you for pointing this out.

Kind regards,

Great, thanks, this worked for me!

FWIW, I was able to workaround the original problem by using the start_streaming followed by the stream_to_file function calls. This had the advantage that I could stream directly to a .npy file and bypass the conversion step. However, I found the need to include (somewhat arbitrarily chosen) sleep statements between start_streaming and stop_streaming calls and subsequent python function calls. Is start_logging preferred to start_streaming from a robustness point of view? I have an MWE script that I can’t seem to upload here, but asking in case this is a known issue?

Hi @gautam,

Your latest post in this thread sounds like something that I’m also working on: we also would like to capture data with the logger and then post-process in Python immediately, so ideally we’d like to have it as .npy directly rather than .li.

Could you perhaps share (part of) your code where you implemented the start_streaming, sleep and stop_streaming?

Thanks in advance!


Hi @dhwielens

Apologies for the incredibly delayed reply - i don’t think i got an email notification about your message and I am just now logging into the support forum again. In case it’s still useful, here is a snippet of code.

logger = Datalogger(mokuIP, force_connect=True)
logger.set_frontend(channel=1, impedance='1MOhm', coupling='DC', range="50Vpp")
logger.set_samplerate(100) # 100 Hz should be plenty fast, and yields a reasonable file size