The tank on the engine should normally be full. It should not get to a half full level. Two things will account for that: The tank on the motor doesn't know it is low on oil or the remote tank is not feeding oil fast enough to keep the engine tank full.
If you get the alarm, pull the cowling with the motor turned off and see what the level is in the tank. If less than full, start the motor and let it idle for a while. See if the engine tank is filling. If it is, you have an oil delivery problem from the remote tank. That is usually caused by an air leak in the pressurized air feed from the motor. It could also be a blockage in the plumbing from the tank to the motor (oil hose or gunked up tank)
There may also be a screen/filter in the oil delivery system on the motor but I am not sure.
So do the check on oil level and refill rate first
