Digital connection device for telephone PABX systems

摘要

A connection device for connecting analog and digital PABX systems via two-wire exchange lines to digital telephone switching devices is formed by a logic module identical for all PABX systems as a central module and a direct dialling-in circuit adapted to the respective operating mode of the PABX system and an interface component. The logic module and the interface component are used for conversion of the different signalling methods between the higher-order digital exchange and the PABX system and for coding and decoding the speech information.