nrfUtil Trace LTE Intermittent Issue

[test_user1]

Hello, 

I am currently using the nrfutil application to convert modem trace logs to pcaps through an automated process. I am seeing intermittent failures with the following text: "Error: No UUID could be found in the provided trace stream" The same modem trace can be converted using the Cellular Monitor Application. What triggers the UUID to show up in the log, is there an AT command or something I can use to ensure the UUID is present? In addition, why does the Cellular Monitor not have the same exception? 

Thanks Again!

[Maria Gilje]

Hello, 

Thank you for your patience and apologies for the delayed response. 

What triggers the UUID to show up in the log, is there an AT command or something I can use to ensure the UUID is present?

The UUID string in the modem trace is used to choose the correct MWF version and subsequently the correct decoder. If you specify a different MFW version than what the UUID string in the modem trace states, the mismatch could cause this error. Could you please verify that you are choosing the correct MFW version? 

In addition, why does the Cellular Monitor not have the same exception? 

In the Cellular Monitor app there is the option to use the automatic MFW detection feature. If you use this, the correct decoder is chosen automatically.

Best regards,

Maria

[test_user1]

Hi Maria, 

Thank you for the information. I confirmed that the firmware version of the device is mfw_nrf91x1_2.0.2. I tried running this command nrfutil trace lte --input-file test_file.bin --database-config ./trace_db/mfw_nrf91x1_2.0.2_trace-db.json --output-pcapng test_file.pcapng and I get the following error:

00:00:00] ------ 0% [Fixed tracing] No UUID could be found in the provided trace stream
Error: No UUID could be found in the provided trace stream

I looked at the Cellular Monitor and do not see this automatic setting, but it makes sense this would be the default when selecting Open trace file in Wireshark. 

Thanks,

Korey

[Maria Gilje]

Hi Korey, 

Which nrfutil and trace versions do you have installed? 

test_user1 said:

I looked at the Cellular Monitor and do not see this automatic setting, but it makes sense this would be the default when selecting Open trace file in Wireshark. 

In the "trace options" section you can select Autoselect for the modem trace database. 

Best regards,

Maria

[test_user1]

Hi Maria,

I am using nrfutil 8.0.0 (54d8087 2025-01-07) and nrfutil-trace 4.0.1 (4c291c5 2025-04-29). 

Thanks!

[Maria Gilje]

Hi Korey, 

Thank you for sharing your versions. 

I have posted an internal ticket to get some feedback from the relevant team. Thank you for your patience.

Best regards,

Maria

[Maria Gilje]

The likely explanation for the error is that nrfutil trace times out when looking for a UUID in the trace stream. If you send an arbitrary AT command early in the trace, the trace command may have enough time to find the UUID. Let me know if it helps.

Best regards,

Maria