A solid-state lighting fixture assembly having a lighting fixture with a socket configured to receive a plug associated with one or more accessories to allow for easy in-field mounting of accessories, e.g., controls, onto installed lighting fixtures. The socket may be internally electrically connected to an auxiliary power output of a driver and/or to a battery power pack within the lighting fixture assembly, thereby providing direct-current voltage power for the accessory and, also, allowing for signal transmission to and from the accessory. Each accessory includes one or more sensors and communication components to provide the connected lighting fixture assembly with specific capabilities including, but not limited to, motion detection, ambient light level detection, ambient temperature measurement and wireless communications. The wireless communication can also be used to control one or a group of lighting fixtures and transmit sensor data associated with, for example, monitoring space utilization and asset tracking.