A backplane and a communications device are disclosed. The backplane includes: at least one fixing plate, multiple connectors, and multiple flexible cables, where signal connection is implemented between corresponding connectors by means of the flexible cables, each of the connectors is provided with a housing and multiple signal pins installed on the housing, and the housing is installed on the fixing plate and is provided with a jack for insertion of a connector of a subcard in the communications device; one end of each signal pin is inserted into the jack, and the other end is connected to each flexible cable. When the communications device provided with the backplane transmits a high-rate signal, transmission quality and a transmission rate are relatively high.

A main unit of a director-class switch including a wire-based backplane located in a chassis, having a plurality of slots configured to receive switch boards. The wire-based backplane includes a plurality of harnesses each including first and second cartridges, a plurality of interface port units mounted on each of the first and second cartridges and cables connecting each of the interface port units of the first cartridge to each of the interface port units of the second cartridge. The harnesses are mounted in the chassis such that the interface port units face ends of the slots in a manner configured to mate with corresponding connectors of switch boards inserted into the slots. A plurality of interface port units are mounted in each slot. Each cartridge includes interface port units which are located in a plurality of different slots.

A device for use in a building management system (BMS) is a controller device. The device includes a base comprising a first processor and a base interface, the first processor being configure to provide control operations for a device in the building system, and a first module installable on and removable from the base. The first module includes a first module interface for receiving power from and communicating with the base via the base interface. In some embodiments, the device includes an optional a second module installable on and removable from the base, the second module comprising a second module interface for receiving power from and communicating with the base via the base interface.