GCS Failsafe

The Ground Station Control (GCS) failsafe controls how Sub will behave if contact with the GCS is lost. The GCS failsafe monitors the time since the last MAVLink heartbeat from the GCS. If no heartbeat is received FS_GCS_TIMEOUT seconds (Default is 5 seconds), the GCS failsafe event will trigger based on your parameter settings. Note that if no GCS is ever connected, the GCS failsafe will remain inactive regardless of parameter settings.

Note

Sub also supports other failsafes, see the Failsafes.

When the failsafe will trigger

The following situations can cause a loss of GCS MAVLink heartbeat, triggering a GCS failsafe event after FS_GCS_TIMEOUT seconds:

  • The operator turns off or otherwise disconnects the GCS

  • The vehicle travels beyond the range of the GCS telemetry radios

  • The GCS telemetry mechanism on either end loses power

  • Wires connecting the GCS telemetry to the autopilot or ground equipment become disconnected

What will happen

When a GCS failsafe is triggered, the vehicle can be configured via parameters to do nothing, send the GCS a warning message, disarm, or change to ALTHOLD or SURFACE modes.

If the failsafe clears (i.e. GCS reconnects and MAVLink heartbeat is restored) the vehicle will remain in its failsafe mode. It will not automatically return to the flight mode that was active before the failsafe was triggered, if it was changed.

Setting the failsafe

In Mission Planner’s full parameter list or full parameter tree, set the FS_GCS_ENABLE parameter to:

  • Disabled (Value 0) will disable the GCS failsafe entirely.

  • Warn Only (Value 1) will send a GCS warning message.

  • Disarm (Value 2)

  • Enter ALTHOLD mode (Value 3), if armed. If mode change fails, disarm.

  • Enter SURFACE mode (Value 4), if armed. If mode change fails, disarm.