- Have 2 activators linked to 1 AND-signal.
- Put a rail block next to the AND-signal and link the AND-signal to other rail blocks
- Both activators are on false, put 1 activator on true
You'll notice that the orientation of that rail next to the AND block has been set to its linked rails, the AND-signal however never turned "true".
Orientations/types should only bet set on a true signal, not on both.
The same applies for undocking something, any signal does that, only true should.