1. Executive standard : GA385- 2002
                     2. Operating voltage: DC24V (pulse modulation)
                     3. Operating current: quiescent current: ≤1mA (the current consumed by the bus); alarm current: ≤120mA@DC24V
                     4. Operating environment: Temperature: -10°C~+55°C; relative humidity: ≤95% (40°C, without condensation)
                     5. Flushing rate: one time/s
                     6. Alarm volume: >85dB (measured at a place 3m in front of the hooter/horn)
                     7. Coding method: Electronic coding
                     8.  Wiring method: Four-wire system, non-polarity two signal buses (L1, L2) and power lines (+24V, GND)
                          Matched host machine: fire alarm control panel (such as AW-AFP2188)