Abstract: Apparatus establishes a connection between a certain network input or input channel and a certain network output or output channel by rearrangement of a three-stage switching network, where, in a specific network condition, each network input or input channel is assigned to a specific network output or output channel. The desired connection is derived by means of successive permutations of the connections within the switching stages until the desired connection has been attained.The apparatus includes a special switching memory wherein the actual network condition is recorded. The organization of the memory is such that the various memory cells are addressed according to the numbering of the interstage links on one side of the central switching stage and each of the cells has a record of which network input and network output is interconnected via the link in question.

Abstract: In a SPC (Stored Program Controlled) system including function blocks of the controlled system proper and function blocks of the controlling computer, an improved function block orientation is introduced by providing each function block with its own program and data stores and with its own addressing device. Via an address decoder, access to control information of the respective function block, registered in its stores is possible only by means of its addressing device identified by a responsive function block number. The central processor unit of the computer communicates with the addressing devices of the function blocks by means of a selection device which is set by the respective function block identifiers or numbers. In each addressing device are stored addressing parameters which define the storage structure of the control information in the associated stores. For performance of a control operation, operation parameters are supplied to the central processor unit.