Telephone exchange circuit with selector stages and real time control - has connecting circuits arranged in groups and connected to central control
摘要
<p>The dialling is performed by dial switches or by keys. Each first stage selector has a connecting circuit and there are a number of connecting circuits which are combined in groups. Each group of circuits has access to dialling receivers through an interstage network, and is also connected through a control unit to a central control. Evaluation of the dialling signals is performed bythe central control which controls accordingly the connection build-up through the corresponding connecting circuit.</p>
