Path finding and marking circuit

Claim 1

A path-finding and marking circuit for a multi-stage switching network employing a plurality of switching matrices and links coupled by guide wires over which offering signals and catching signals are applied, each stage of the multi-stage switching network including a switching matrix together with offering signal inlets and outlets and catching signal inlets and outlets, said offering signal inlets and outlets providing access to path means over which, in a first step, all links usable for a desired connection are marked by an offering signal transmitted from an offering signal inlet on one side of a switching matrix to an offering signal outlet on the other side of the switching matrix, and on which, in a second step, one out of several offered links is marked as ''''selected'''' by a catching signal sent back from a catching signal inlet on the other side of said switching matrix to a catching signal outlet on said one side of the switching matrix over path means provided through said catching signal inlets and outlets, wherein the improvement comprises a plurality of logic means in each stage coupling respective inlets and outlets to each other and to inlets of the switching matrix, said logic means including a selection circuit coupled to each matrix, said logic means responding to the simultaneous presence of offering and catching signals whereby said selection circuit marks crosspoints in the switching matrix.