self test function

forward scatter light detection direct from Wanlin Fire Protection — 12-year factory experience, WL-SFP200 smart fire detector certified CE/EN14604/EN54/UL217/UL268/FCC/QCVN. Key specs: Photoelectric Smoke Sensor + Electrochemical CO Sensor + NB-IoT Cellular Communication + Multi-Sensor Fusion, NB-IoT + IoT Cloud Platform + Dual Alarm (Smoke + CO) + SMS/Push···