Failure to establish serial com ports

Hi there,

Following your quick start guide, 4 four serial com ports should be etablished on the PC when the EVB is connected via the micro USB. However, when I connect the EVB it is showing up in the device manager as an "Unknown USB Device (Device Descriptor Request Failed)" and as such no COM ports are made available.


It is still possible to connect to the device via the Ethernet connection using http://openrtk/ however the python device driver is unable to connect.

Could you please assist me with this issue?


You may lack the appropriate driver,try this ,please.
CDM v2.12.28 WHQL Certified FT4232H.7z


So I've got the driver now. The COM ports are being established in the device manager and I can get some data off of the device using the python driver. However, it still won't connect properly to the web portal (

In the logs I'm getting the following warningshow up amounst the INFO messages:

2021-09-17 15:40:33,340 - WARNING: error happened when decode the payload of packets, pls restart driver: pack expected 36 items for packing (got 30)

Hi Boreham,
Are you sure you're using the latest Pythondriver? If not,please download the latest Pythondriver(verison:2.5.0)
And try Google Chrome please.If you try all this and it doesn't work.please give me the sn number.

Hi @zrs

The sn number of our device is 2075000309

I've tried with the v2.5.0 of the python driver (we were previously using 2.5.2) and google chrome. It does now seem to work, however we do occasionally get the error message:

Exception when log device connection to db: HTTPSConnectionPool(host='', port=443): Max retries exceeded with url: /api/deviceConnections/log (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1108)')))

Hi @Nicholas-Boreham
Please ignore this problem for now, it does not affect your usage, but we will continue to reproduce this problem .So we need more information:
1.What operating system do you use.
2.How do you run the python driver? exe file or source code.

I am using windows 10 with the v2.5.0 python driver. The Python driver is being run via powershell.

I need to thank you for this post!! I definitely loved it and also bookmarked to check out new things you post.

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