Telephone switching system with central data carrier - has logic circuit combining request signals to produce free signal only when one request signal is present

摘要

The telephone switching system has devices of a first kind (data carrier drives) arranged centrally w.r.t. devices of a second kind (central drives). The latter are provided with request lines. The devices of a first kind have inputs equal in number to the number of request lines. The inputs are connected to the inputs of logic network that combines simultaneous request signals with one another in such a way that only when one single request signal is present does a 'free' signal appear at the output of the logic. This 'free' signal is passed to all the devices of a second kind via a shared line.