The ground station announcing itself

This text was not written by the flight controller: it came in from outside and ArduPilot only copied it into the log. Mission Planner sends its name and version each time it connects, so the line marks the moment a ground station was plugged in or linked up, and which version. In the log a text from your ground station (the system ID in SYSID_MYGCS, 255 by default) is prefixed “GCS:”; one from any other MAVLink device, such as a companion computer or a gimbal, “SRC=” with its system and component ID.

Parameters to look at

Where to do it:Setup & Tuning Guide