The PA-24PRTBA-B (PRT) circuit card is a digital interface supporting voice and data communications at 1.5 M bit/second equipped with a Link Access Procedure for a D-Channel (LAP D) controller based on the ITU-T I/Q series. This card provides a Primary Rate Access Interface (PRI) with the system. A built-in resonance circuit extracts clock signals that are supplied from the network, so that the system may be in exact synchronization with the network. To obtain appropriate speech level, this card is also equipped with a mask ROM in which typical PAD patterns have been already written. A desired PAD value can be easily selected by key settings and programming from the MAT |