Starting modem tracing

Note

If you already have a binary trace data file and would like to have it in a different format, see Converting trace data.

Complete the following steps:

Make sure you have configured your application for tracing.
Identify the device's serial port for tracing by listing the devices with the modem device trait:
```
nrfutil device list --traits modem
```
Note

When selecting a serial port for the trace:
- For nRF91 Series devices, pick the serial port with the highest serial port number.
- For the nRF93M1 DK, pick the serial port of VCOM1 instead.
To trace continuously, run the nrfutil trace lte and specify the tracing options - at least the input serial port and the output file format.
Use the following command pattern:
```
nrfutil trace lte --input-serialport <serial_port> --output-raw <file_name>
```
For example, run the following command to save the input from the COM10 serial port to trace.raw:
```
nrfutil trace lte --input-serialport COM10 --output-raw trace.raw
```
When done, stop tracing by pressing CTRL-C. The command exits with a zero exit code when you stop tracing this way. The binary trace file is created in the current directory unless a different path is specified. You can view the file size in bytes while the trace is running.

The raw binary output file contains all traffic to and from the modem. Raw binary files are primarily used as an attachment when assistance is needed from Nordic Semiconductor support. Some of the traffic is proprietary to Nordic Semiconductor and not publicly available.

Note

By default, the PcapNG, Wireshark, and modem text outputs include only AT, IP, LTE-RRC, and NAS-EPS packets. To include all packet types, add --modem-trace-filter all to the command. You cannot combine the all value with other filter values. The raw binary output is not filtered.

Note

If tracing into a PcapNG file does not produce any trace, reset the board and try again.