Communication link for a lighting control system

A light-generation module configured to receive a bus voltage from a power supply, wherein the power supply is configured to generate the bus voltage from an alternating-current (AC) mains line voltage, the light-generation module comprising:

• first and second electrical connections configured to receive the bus voltage from the power supply, the bus voltage referenced to a circuit common;
• a third electrical connection configured to receive a control signal from the power supply, the control signal referenced to the circuit common;
• at least one emitter configured to emit light;
• a drive circuit configured to receive the bus voltage and control an amount of current conducted by the at least one emitter;
• and
• a control circuit configured to control the drive circuit to adjust the amount of current conducted by the at least one emitter to adjust an amount of light emitted by the light-generation module, the control circuit configured to detect a synchronization pulse in the control signal each line-cycle of the AC mains line voltage, and control the at least one emitter in response to the synchronization pulses;
• wherein the control circuit is configured to control the control signal at the third electrical connection to transmit data to the power supply between the synchronizations pulses received in each line-cycle of the AC mains line voltage.