Abstract: Devices, systems, and methods for event device system operation are described herein. In some examples, one or more embodiments include a controller comprising a memory and a processor to execute instructions stored in the memory to transmit, to a plurality of event devices via a power line communications (PLC) protocol, a synchronization message according to a predetermined schedule to cause the plurality of event devices to synchronize timing of the plurality of event devices with the controller, transmit, to the plurality of event devices via the PLC protocol, a command according to the predetermined schedule, and receive, from the plurality of event devices via the PLC protocol, a response to the command according to the predetermined schedule.

Abstract: A communication protocol facilitates transmission at maximum rates for various types of cables. The protocol can be used to transmit information between a common control unit and a plurality of spaced apart devices coupled thereto. Alternately, the protocol can be used for transmission of information between devices. One control unit or device transmits clock pulses, while in a low impedance state. The devices respond to the clock pulses and transmit data on the communications link, in a low impedance state, when the source of clock pulses assumes a high impedance state. One or more features of transmitted signals can be used to implement one or more synchronized functions.