A control system for mounting to a rail, the control system comprising: a base (40, 42) including a body formed by a mounting portion (50, 108) and a side portion (52, 110) extending outwardly from a front side of the mounting portion (50,108) at about a right angle to form an L-shaped base (40, 42), the mounting portion (50, 108) further including an enlarged opening extending through the front side and into the interior of the mounting portion (50, 108) and a circuit board connector at the front side of the mounting portion (50, 108), the enlarged opening and the circuit board connector forming a socket, the body having a channel formed therein that is opposite the front side and adapted to receive the rail, the side portion (52, 110) comprising at least one connector (92, 112) on its free outer end, and opposite the rail, for establishing communication between the base (40, 42) and one or more devices, the base (40, 42) further including a latching assembly being mounted to the body that includes a movable lever and at least one latching member (72, 80), the lever being movable between a latched position and an unlatched position, wherein the movement of the lever between the unlatched and latched positions moves the at least one latching member (72, 80) into and out of the channel, whereby when the rail is disposed in the channel and the lever is moved to the latched position, the at least one latching member (72, 80) moves into the channel, thereby trapping the rail in the channel and securing the base to the rail; and a module (12,14) for removable mounting to the base (40,42), the module (12,14) comprising circuitry for processing control signals and a plug, the plug being configured to be received by the socket to establish communication between the base and the module (12, 14), wherein when the module (12,14) is mounted to the base (40,42), the module (12,14) covers the lever of the latching assembly so as to be inaccessible, and wherein when the module (12, 14) is mounted to the base (40, 42), the module (12, 14) extends outwardly from the body and is disposed laterally from the side portion (52, 110). a base (40, 42) including a body formed by a mounting portion (50, 108) and a side portion (52, 110) extending outwardly from a front side of the mounting portion (50,108) at about a right angle to form an L-shaped base (40, 42), the mounting portion (50, 108) further including an enlarged opening extending through the front side and into the interior of the mounting portion (50, 108) and a circuit board connector at the front side of the mounting portion (50, 108), the enlarged opening and the circuit board connector forming a socket, the body having a channel formed therein that is opposite the front side and adapted to receive the rail, the side portion (52, 110) comprising at least one connector (92, 112) on its free outer end, and opposite the rail, for establishing communication between the base (40, 42) and one or more devices, the base (40, 42) further including a latching assembly being mounted to the body that includes a movable lever and at least one latching member (72, 80), the lever being movable between a latched position and an unlatched position, wherein the movement of the lever between the unlatched and latched positions moves the at least one latching member (72, 80) into and out of the channel, whereby when the rail is disposed in the channel and the lever is moved to the latched position, the at least one latching member (72, 80) moves into the channel, thereby trapping the rail in the channel and securing the base to the rail; and a module (12,14) for removable mounting to the base (40,42), the module (12,14) comprising circuitry for processing control signals and a plug, the plug being configured to be received by the socket to establish communication between the base and the module (12, 14), wherein when the module (12,14) is mounted to the base (40,42), the module (12,14) covers the lever of the latching assembly so as to be inaccessible, and wherein when the module (12, 14) is mounted to the base (40, 42), the module (12, 14) extends outwardly from the body and is disposed laterally from the side portion (52, 110).