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 Access Interface (PRI) with the system. A built-in
resonance circuit extracts clock signals, which 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.
Figure 3-181 Location of PA-24PRTB-A (24PRT) within 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