| 摘要 |
The controlling of a plurality of smoke and heat evacuation and ventilation (SHEV) devices is shown, in which the devices are connected to field wiring that also includes fire detection devices and alarms. A constant limited current (705) is supplied in a first direction for fire detection. A non-limited voltage is applied to supply alarm current 708 in a second direction for sounding alarms and opening the SHEV DEVICES. A non-limited positive voltage 712 is applied to supply reset current in the first direction for closing the SHEV devices. |
