Timbering and walling control for controlling the movements of timbering and walling units in the coal face of a mine

A longwall support control for controlling the movements of a plurality of longwall support units in the longwall of a mine, comprising:

• a central control system, and
• a separate mining shield control device locally and operationally associated to each longwall support unit, the mining shield control devices being connected to the central control system and serially connected to one another by means of at least one bus line, through which each of the mining shield control devices can be called up from the central control system or an adjacent mining shield control device for inputting a control command, and with each mining shield control device being programmed such that it is possible to deliver for execution to its associated longwall support unit control commands that are received via the one bus line, and with each mining shield control device storing a code word uniquely associated with the respectively called up mining shield control device, and with each mining shield control device being programmed to execute a control command only when the code word is received with the control command,
• wherein, each mining shield control device comprises a switching element, which permits separating a phase conductor of the at least one bus line, the switching element being normally closed so as to allow signals to pass and being opened to effect a separation of the one bus line upon the occurrence of a failure, and wherein the central control system comprises a primary and a secondary central control system connected at respective opposite ends of the one bus line so that the mining shield control devices are positioned between the primary and secondary control systems along the bus line.