Digital load control system providing power and communication via existing power wiring

A controller for use in a load control system for controlling a power delivered from an AC power source to an electrical load, the controller comprising:

• a controllably conductive device adapted to be coupled in series electrical connection on a power wiring between the AC power source and a power device of the load control system;
• a control circuit coupled to the controllably conductive device for rendering the controllably conductive device conductive each half-cycle of the AC power source to generate a phase-control voltage on the power wiring, the control circuit being configured to transmit a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage;
• and
• a reverse receiving circuit coupled in parallel electrical connection with the controllably conductive device and configured to receive a reverse digital message from the power device via the power wiring, the reverse digital message being split up into two or more packets;
• wherein the control circuit is configured to transmit a continuation pattern between the packets of the reverse digital message.

A power device for use in a load control device for controlling a power delivered from an AC power source to an electrical load in response to a controller that is coupled in series electrical connection between the AC power source and the power device, the power device comprising:

• a forward receiving circuit adapted to be coupled to the controller via a power wiring, and configured to receive a phase-control voltage from the controller via the power wiring;
• a control circuit operatively coupled to the forward receiving circuit for receiving a forward digital message from the controller in response to digital information encoded in timing edges of the phase-control voltage;
• and
• a reverse transmitting circuit adapted to be coupled to the controller via the power wiring;
• wherein the control circuit is operatively coupled to the reverse transmitting circuit for transmitting a reverse digital message to the controller via the power wiring, the reverse digital message being split up into two or more packets;
• and
• wherein the control circuit is configured to receive a continuation pattern between the packets of the reverse digital messages.