Trace AT commands
Note
These AT commands are Experimental.
This page describes the AT commands for controlling the shared UART trace backend.
The AT#XLOG command is always available in the default build.
The AT#XTRACE command requires building with the overlay-trace-backend-uart.conf configuration overlay.
See Shared UART log and trace backend for a full description of the feature.
The Zephyr application log backend (AT#XLOG) and the modem trace backend (AT#XTRACE) share a single UART.
They are mutually exclusive: enabling one while the other is active returns an error.
During boot, the UART outputs logs from B0, MCUboot, and the application.
After initialization, the UART is suspended when no backend is active and resumed when at least one backend is enabled.
The trace UART is configured at 1000000 baud rate to support the high data rate required for the modem traces. Trace data is available through the UART1 interface (VCOM1 on the nRF9151 DK).
Application log AT#XLOG
The AT#XLOG command enables or disables the Zephyr application log backend and the shared UART.
Set command
The set command enables or disables the Zephyr application log backend.
Syntax
AT#XLOG=<mode>
The
<mode>parameter is an integer:0- Disable the application log backend and suspend the UART.1- Resume the UART and enable the application log backend.
Note
Returns ERROR if AT#XTRACE=1 has been issued.
Read command
The read command returns the current state of the application log backend.
Syntax
AT#XLOG?
Response syntax
#XLOG: <mode>
The
<mode>parameter reflects the current state (0= disabled,1= enabled).
Test command
The test command returns the supported parameter range.
Syntax
AT#XLOG=?
Response syntax
#XLOG: (0,1)
Example
AT#XLOG=1
OK
AT#XLOG?
#XLOG: 1
OK
AT#XLOG=0
OK
Modem trace AT#XTRACE
The AT#XTRACE command enables or disables the modem trace backend on the shared UART.
When enabled, the UART is resumed and the modem is instructed to generate full-level traces (AT%XMODEMTRACE=1,2).
When disabled, the modem is instructed to stop generating traces (AT%XMODEMTRACE=0) and the UART is suspended.
Set command
The set command enables or disables the modem trace backend.
Syntax
AT#XTRACE=<mode>
The
<mode>parameter is an integer:0- Disable modem traces and suspend the UART.1- Resume the UART and enable the modem trace backend.
Note
Returns ERROR if AT#XLOG=1 has been issued.
Read command
The read command returns the current state of the modem trace backend.
Syntax
AT#XTRACE?
Response syntax
#XTRACE: <mode>
The
<mode>parameter reflects the current state (0= disabled,1= enabled).
Test command
The test command returns the supported parameter range.
Syntax
AT#XTRACE=?
Response syntax
#XTRACE: (0,1)
Example
AT#XTRACE=1
OK
AT#XTRACE?
#XTRACE: 1
OK
AT#XTRACE=0
OK