Control systems and methods for independent control of power systems, particularly lighting network branches, and separate control of individual branch components. Multi-branch systems comprise independently controllable branches that inter-communicate via PLC communications. In each branch, components such as ballasts, local control units, sensors, actuators, and repeaters, may exchange commands and queries independently of a branch remote control unit (BRCU). Alternatively, a BRCU may manage or arbitrate communications, or interact with other BRCUs, other control units and external management systems. Ballasts include a multi-channel ballast that enables close-loop control of individual fixtures, or of individual dimmable or non-dimmable lamps within a fixture. The close-loop control is facilitated by sampling circuits/sensors co-located with each controlled fixture or lamp. All controllers are preferably implemented using an integrated digital controller. The PLC communication is preferably carried out by a direct spread spectrum method that eliminates side lobes from a cross-correlation function, using an anti-collision protocol.