Tigo’s RSS Signal Detector is a functionality testing device for sensing the Power Line Communication (PLC) signal from the Tigo RSS Transmitter to the TS4-F or TS4-R-F (Fire Safety) units. The Detector is used during installation to verify that the TS4-F units are receiving the keep-alive signal from the Transmitter. This is the handheld, failsafe tool to confirm that your PV system is compliant with NEC 2017 690.12 rapid shutdown specifications.