Mission Protocol - Clarifications on Geofence and Rally + Regular

[hamishwillee]

Mission Protocol covers regular missions in detail, and mentions how you set the two "new in MAVLink 2" types: - MAV_MISSION_TYPE_FENCE, MAV_MISSION_TYPE_RALLY

1. For Rally Points, my assumption is:
   • A rally point is just like a flight plan mission except that you only use the MAV_CMD_NAV_RALLY_POINT as a command, and of course the mission_type
   • MAV_PROTOCOL_CAPABILITY_MISSION_RALLY should be set to specify support.

Is there anything else to them?

2. For Geofence,
   • I assume that you can define a bunch of things about the fence using these messages: MAV_CMD_NAV_FENCE_RETURN_POINT, MAV_CMD_NAV_FENCE_POLYGON_VERTEX_INCLUSION, MAV_CMD_NAV_FENCE_CIRCLE_INCLUSION, MAV_CMD_NAV_FENCE_CIRCLE_INCLUSION, MAV_CMD_NAV_FENCE_CIRCLE_EXCLUSION
   • Also that you can turn it on and off at different points in the mission using MAV_CMD_DO_FENCE_ENABLE?
   • If you support the feature you enable MAV_PROTOCOL_CAPABILITY_MISSION_FENCE

Is that right? In PX4 can these be sent outside of missions?

How do you use FENCE_ACTION, FENCE_BREACH ?