Once the Flight control computer determines the proper speed for each propeller, it uses a high speed data circuit on the Power Distribution board (PDB) to communicate control instructions for each motor. The FC inject the control signal onto the PDB. Each individual BL-Cntrl has it’s own electronic address, and accepts only the control instructions sent from the FC that are address to it alone. The BL-Cntrl also communicates information back to the FC using the same method.
Battery power is also distributed to each BL-Cntrl Board (ESC) using this bus.
Overall, it is a well designed and effective way to provide communication between the Flight controller and the motor controllers while at the same time providing a solid path for battery power.
Pictured below are the Power Distribution Boards for the Quad, Hexa, and Okto with the Motor Controllers,(ESC) boards already mounted.