A fence was switched on or off
What ArduPilot says:
- Min Alt fence enabled (auto enable)
ArduPilot says which fences it has just switched on or off. “Max Alt, Circle and Polygon fences auto-enabled” comes at arming and “… auto-disabled” at disarming when FENCE_AUTOENABLE is 3, or after an automatic take-off and during landing when it is 1 or 2. “… enabled” and “… disabled” come from a DO_FENCE_ENABLE command in a mission. The minimum-altitude fence (FENCE_TYPE bit 3) is never on at take-off: it turns on by itself once the aircraft is FENCE_MARGIN above FENCE_ALT_MIN (“Min Alt fence enabled (auto enable)”) and goes off again for landing.
Min Alt is never in the “auto-enabled” line at arming: it gets its own line later. “Polygon” is listed whenever bit 2 of FENCE_TYPE is set, even when no drawn fence has been uploaded, so the line does not prove that one is on the aircraft.
Parameters to look at
| Parameter | What it is |
|---|---|
FENCE_AUTOENABLE | Fence Auto-Enable |
FENCE_ENABLE | Fence enable/disable |
FENCE_TYPE | Fence Type |
FENCE_ALT_MIN | Fence Minimum Altitude |
FENCE_MARGIN | Fence Margin |
Where to do it:Failsafe Explainer
The code that sends it
Min Alt fence enabled (auto enable)
libraries/AC_Fence/AC_Fence.cpp AC_Fence::auto_enable_fence_floor() · Open in ArduPilot Copter-4.7.1