> For the complete documentation index, see [llms.txt](https://docs.ceruleansonar.com/c/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ceruleansonar.com/c/tracker-650/technical-details/api/outgoing-message-formats-tracker-650-to-host/freeform-error-and-informational-messages-usddvtxt.md).

# Freeform Error and Informational messages ($DVTXT)

The Tracker 650 may output quite a few informational messages that are not needed for navigation, but which may make integration and debugging easier. There are no periodic freeform messages. You can liken it to a Unix or Linux boot console display. Most of it will look like gibberish to you, some of it will make sense if you’re having a problem of some sort, and all of it can be ignored until there is a problem and you need to call the factory for help. You will see more boot messages on the serial port; these are output before the Ethernet link is established and mostly report on Ethernet link establishment progress.

Many freeform messages are packaged in an NMEA-type $DVTXT packet.

Nearly all freeform messages are formatted as an NMEA message starting with $DVTXT.

Example:

$DVTXT,Firmware release version Aug 22 2023