Common Reset Reasons

DM Support

Modified on: Thu, 23 Mar, 2023 at 1:29 PM

When a device resets, you will typically see a log such as the one below:

Debug[GEN][Crit]: VBat = 4888 mV, Reset = 0X4, Watchdog = 0x1

There are two values that are of interest here - the reset and watchdog reset reasons. The reset reasons tell you what kind of reset occurred - typically either a power on, brownout, or a firmware initiated reset. If the firmware initiated the reset, then the watchdog reason will tell you why.

Reset Reasons

The following are the most common reset reasons:

Reset Reason	Explanation	Applicable Devices
0x1	Power on reset. This mainly occurs when power is first supplied. It can also occur during severe brownouts.	All DM devices.
0x2	Brown out reset. The voltage dipped below the brown out threshold. Typically seen when batteries are depleted. Battery insertions can also appear as brownouts occasionally.	All DM devices.
0x4	Watchdog reset. The firmware reset the device. The reason it did so is detailed by the watchdog reset reason.	All DM devices
0x10/0x14	Under voltage lockout reset. The voltage dipped below the minimum voltage threshold. Typically seen when batteries are getting low.	Battery powered devices.
0X110/0x101	Indicative of flash issues. 0x101 being an issue reading the flash, and 0x110 being an issue powering the flash.
0XA	Reset from Provisioning Tool	All CAT-M1/NB-IoT Devices
0XC	Brown out Reset
0X8	power on reset & Brown out

Watchdog Reset Reasons

Watchdog reasons less than 0x100 are manually initiated resets, whilst watchdog resets greater than or equal to 0x100 are caused by the device resetting itself to try and rectify an error state. The watchdog reasons greater than 0x100 tend to be device specific and are far less frequent so are not included here for brevity.

Common Watchdog Reset Reasons

Watchdog Reset Reason	Explanation	Applicable Devices
0x0	Either not a watchdog reset, or an unknown error occured.	All DM devices.
0x1	App reset. This occurs when the device resets itself due to changed conditions. Typical reasons include: The parameters were updated Firmware was downloaded The device must switch to recovery mode/back to normal operation A reset async message was received	All DM devices.
0x2	No comms. The device could not communicate with the server for 3 days or more. The device resets itself to retry an upload with loose upload restrictions. This also triggers the use of backup admin params when applicable.	All DM devices.
0x3	SMS reset. The device received an SMS command to reset. On some devices, the app reset (0x1) is used instead.	Mainly powered devices.
0x4	Async message reset. The device recieved an async message command to reset. On some devices, the app reset (0x1) is used instead.	Mainly powered devices.

Battery Powered Watchdog Reset Reasons

Watchdog Reset Reason	Explanation	Applicable Devices
0x5	Backup admin params expired. The device was testing the backup admin params and is now reverting back to the standard admin params.	Battery powered devices.

Powered Watchdog Reset Reasons

Watchdog Reset Reason	Explanation	Applicable Devices
0x5	Under voltage lockout reset. The uvlo was triggered. This is typically seen when the external voltage is too low and the backup battery is depleted.	Powered devices.
0x6	Backup admin params expired. The device was testing the backup admin params and is now reverting back to the standard admin params.	Powered Devices.
Watchdog = 7	Reboot due to modem update	Powered devices