Intelligent powered device (PD) control system including a switch system, state detector (SD), intelligent control device (ICD), and a PD. The switch system includes one or more conventional electrical switches. Each switch includes an interface to receive selection of a switch system state change between conductive and non-conductive states. The switch system includes a conductor pair(s) indicative of switch system state based on the selection. The SD signals the detected state to the ICD. The switch system output is in electrical connection with the detector such that, in the conductive state a loopback is formed in the switch system and SD, and in the non-conductive state no loopback is formed. The ICD receive the message from the state detector and transmits a fixture control command based on the message. The PD receives the command from the ICD via the data communications network, and controls its state based on the command.