![Nortel NT5D12 Скачать руководство пользователя страница 109](http://html1.mh-extra.com/html/nortel/nt5d12/nt5d12_installation-manual_1706448109.webp)
NTD12 Dual-port DTI/PRI card description and installation
Page 101 of 188
ISDN PRI Installation
NTBK51AA daughterboard
The optional dual-port Downloadable D-Channel daughterboard (DDCH,
NTBK51AA) has been introduced to be used with the NT5D12 DDP in
system hardware configurations as an alternative to an MSDL or a DCHI card
(refer to
“Hardware required for DDP configuration” on page 113
for possible
configurations.)
The NTBK51AA DDCH daughterboard is a two-port D-Channel Handler
card supporting all the features of the existing four port MSDL (NT6D80). It
eliminates the need for a D-Channel Handler or an MSDL card, and
associated cables.
Note:
Only one version, the NTBK51AA, can be used in DDP cards.
The newer NTBK51BA version has only 30+30 pin connectors (instead
of 40+30 pins in the AA version). The missing 10 pins in the BA version
prohibits usage of port 0 on the DDP card.
The NTBK51AA can support a maximum of 32 (16*2) D-Channels per
system (the MSDL can support a maximum of 64.)
Note 1:
The software allocation for NTBK51AA DDCH is similar to the
MSDL. It is both physical and logical, and supports D-Channel
functionality only.
Note 2:
Port 0 has to be an even loop on the DDP, and Port 1 has to be
an odd loop. Port 2 and Port 3 should not be configured.
The connection between the DDP card and the DDCH daughterboard is made
using two headers: one 30 pin and one 40 pin connector.
The NTBK51AA DDCH card consists of the following:
— 16 MHz MC68EC020 microprocessor;
— MC68901 Multi-function Peripheral Controller;
— Z16C35 Integrated Serial Communication Controller;
— One Mbyte of main memory;
— 512 KBytes of Flash EPROM.