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 wireless communications capability enables field personnel to communicate with a remote control console of a distributed system. A hand held communications unit generates console related messages that are coupled, via local devices to the remote console.

Abstract: A wireless communications system incorporates a plurality of synchronized wireless units. Each unit minimizes energy requirements by entering a low current, inactive, state between synchronizing signals. The unit automatically enters an active state prior to receipt of the next synchronizing signal.

Abstract: A wireless communications capability enables field personnel to communicate with remote a control console of a distributed system. A hand held communications unit generates console related messages that are coupled, via local devices, to the remote console.

Abstract: A self-testable photoelectric smoke detector incorporates a housing which defines an internal smoke chamber. The housing carries a laser diode and a radiation sensor along with a supplemental source of test radiant energy. When a test is initiated, the operational characteristics of the laser diode are monitored simultaneously with energizing the source of test radiant energy. Signals from a scattered radiant energy sensor are evaluated via control circuitry, along with signals indicative of performance of the laser diode to determine whether or not the laser diode as well as the radiation sensor are functioning properly.