A flexible cable is provided for a lighting system having a power supply
that includes a power supply input to receive a first signal having a
first frequency and a circuit for converting the first signal to a second
signal, and at least one luminaire coupled to a lamp driver. The cable
comprises a first leg of wires for carrying the second signal. The first
wire electrically connects a loop output of the power supply to an input
of the lamp driver and a second wire electrically connects an output of
the lamp driver to a loop return of the power supply. The cable further
comprises a second leg of wires electrically connected to a ground of the
power supply and the ground of the lamp driver. The second signal has a
substantially constant current and a second frequency distinctly higher
than the first frequency. The flexible cable further comprises a modular
connector.