Capturing trace data from an nRF9160 modem to a binary file

nRF Util trace can be used to collect Universal Asynchronous Receiver/Transmitter (UART) traces from the nRF9160 System in Package (SiP) or any device supporting modem trace. The trace can be used to analyze the communication between the device and the Long-Term Evolution (LTE) network.

1. Identify the device's serial port for tracing:

   nrfutil device list --traits modem

   When selecting a serial port for the trace, pick the serial port with the highest vcom value.
2. To trace continuously, for example, on COM10 and output to Packet Capture Next Generation (PcapNG) format, run the following:

   nrfutil trace lte --input-serialport COM10 --output-pcapng live-trace.pcapng

3. To stop tracing, press CTRL+C.
   The trace file is created in the current directory unless a different path is specified. You can view the file size in bytes while trace is running.

nrfutil trace lte --input-serialport COM10 --output-wireshark path_to_wireshark