Systems and methods for controlling electrical loads in one or more areas. The system includes a room controller having a microprocessor for accessing data and providing commands, memory for storing information operably connected to the microprocessor, a relay for powering a load based on commands from the microprocessor, and a port for connecting a peripheral device. The system also includes a peripheral device connected to the port and configured to send data including a device type and a device instance byte to the controller indicating the type of peripheral device. The device instance byte includes a port number identifying the port and a slot number identifying a time slot within a time domain multiplexing cycle. The system also includes a load connected to the relay.