A non-transitory machine-readable medium comprising: an emergency lighting device programming in an emergency lighting device memory (235, 335, 435), wherein execution of the emergency lighting device programming by an emergency lighting device processor (230, 330, 430) configures an emergency lighting device (40A-40L) to implement functions to: in response to determining that a line power source for a subset of member devices or all member devices of a lighting control group is interrupted, wherein the member devices of the lighting control group comprise the emergency lighting device and a non-emergency lighting device (10A-10D), enter an emergency active state to control a light source of the emergency lighting device, via a driver circuit, to emit emergency illumination lighting; upon entering the emergency active state, transmit, via a wireless lighting control network (5, 7), an emergency active state message to the lighting control group; receive, via the wireless lighting control network, an emergency exit message from a member device being configured as a group monitor of the lighting control group indicating to exit the emergency active state; and in response to receiving the emergency exit message from the member device, exit the emergency active state by controlling the light source, via the driver circuit, to discontinue emitting the emergency illumination lighting; and a non-emergency lighting device programming, wherein execution of the non-emergency lighting device programming by a non-emergency lighting device processor configures the non-emergency lighting device (10A-D) to implement a function to: after being powered on by the line power source, receive, via the wireless lighting control network, the emergency active state message; the non-transitory machine-readable medium being characterized in that execution of the non-emergency lighting device programming configures the non-emergency lighting device to implement functions to: in response to receiving the emergency active state message, initiate a timer for a predetermined wait period; and in response to receiving, via the wireless lighting control network, the emergency exit message before expiry of the predetermined wait period, stop the timer and halt transmission of an intermediary emergency exit message to the group monitor; or upon expiry of the predetermined wait period, transmit the intermediary emergency exit message to the group monitor. in response to determining that a line power source for a subset of member devices or all member devices of a lighting control group is interrupted, wherein the member devices of the lighting control group comprise the emergency lighting device and a non-emergency lighting device (10A-10D), enter an emergency active state to control a light source of the emergency lighting device, via a driver circuit, to emit emergency illumination lighting; upon entering the emergency active state, transmit, via a wireless lighting control network (5, 7), an emergency active state message to the lighting control group; receive, via the wireless lighting control network, an emergency exit message from a member device being configured as a group monitor of the lighting control group indicating to exit the emergency active state; and in response to receiving the emergency exit message from the member device, exit the emergency active state by controlling the light source, via the driver circuit, to discontinue emitting the emergency illumination lighting; and a non-emergency lighting device programming, wherein execution of the non-emergency lighting device programming by a non-emergency lighting device processor configures the non-emergency lighting device (10A-D) to implement a function to: after being powered on by the line power source, receive, via the wireless lighting control network, the emergency active state message; the non-transitory machine-readable medium being characterized in that execution of the non-emergency lighting device programming configures the non-emergency lighting device to implement functions to: in response to receiving the emergency active state message, initiate a timer for a predetermined wait period; and in response to receiving, via the wireless lighting control network, the emergency exit message before expiry of the predetermined wait period, stop the timer and halt transmission of an intermediary emergency exit message to the group monitor; or upon expiry of the predetermined wait period, transmit the intermediary emergency exit message to the group monitor. in response to receiving the emergency active state message, initiate a timer for a predetermined wait period; and in response to receiving, via the wireless lighting control network, the emergency exit message before expiry of the predetermined wait period, stop the timer and halt transmission of an intermediary emergency exit message to the group monitor; or upon expiry of the predetermined wait period, transmit the intermediary emergency exit message to the group monitor.