CHAPTER 3 NDA-24296
Page 582
Revision 1.0
PA-24PRTB-A
Primary Rate Interface Trunk

PA-24PRTB-A

Primary Rate Interface Trunk

1. General Function
The PA-24PRTB-A ( PRT) circuit card is a digital interface supporting voice and data communications at
1.5 M bit/sec. Being 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 Acc es s Int erface (PR I) with th e system. A built-in
resonance circuit extracts clock signals, which are supplied from the network, so that the system may be in
exact synchronizat ion wit h the networ k. To obtain appr opria te speech le vel, this card is also e qui pped with
a mask ROM in which typica l PAD patterns have been al ready wri tten. A desired PAD value can be easily
selected by key s ettings and pro g ramming from the MAT.
Figure 3-181 Location o f P A-24 PRT B - A (24PRT ) w ithin the System
I/O Local Bus
CPU
System Clock
INT TSW INT
Speech Path (PCM Signal)
D-channel Signaling Link
2-wire
2-wire
PLO
1.544MHz Clock
Extraction from Network
24ch
T
R
ISDN
NETWORK
24PRT