A lighting control system includes a control group including a plurality of member devices which includes a power monitor and an emergency luminaire. The power monitor includes a power supply driven by a normal power source. The power monitor implements the following function. Transmit, via a wireless lighting control network, a normal power active message to the control group repeatedly at a predetermined time interval. The emergency luminaire includes an emergency light source to continuously emit illumination lighting during an emergency, and a power supply driven by an emergency power line. The emergency luminaire implements the following functions. Track an active message gap time. Reset the active message gap time after receiving the normal power active message. In response to the tracked active message gap time exceeding an active message timeout, enter an emergency mode active state by controlling the emergency light source to continuously emit the illumination lighting.