Owner's manual

Architecture 769
• Task handler: also referred to as an executive, the task handler
provides orderly per-channel task execution to maintain real-time task
ordering constraints.
•
Transmit voice: inserts digital pads, manipulates transmit AB bits for
DS1, and provides graceful entry into T-Link data mode when the data
module connected to the DTI/PRI trunk is answering the call.
• Receive voice: inserts digital pads and provides graceful entry into
T-Link data mode when the data module connected to the DTI/PRI
trunk is originating the call.
• T-Link data: a set of transmit and receive vectored subroutines which
provides T-Link protocol conversion to/from the DM-DM protocol.
•
Receive ABCD filtering: filters and debounces the receive ABCD bits
and provides change of state information to the system.
•
Diagnostics
• Self-test
Digital pad
The digital pad is an EPROM whose address-input to data-output transfer
function meets the characteristics of a digital attenuator. The digital
pad accommodates both µ255-law and A-Law coding. There are 32
combinations each for µ255 to µ255, µ255 to A-Law, A-Law to µ255, and
A-Law to A-Law. These values are selected to meet the EIA loss and level
plan. See Table 320 "Digital pad values and offset allocations" (page 769).
Table 320
Digital pad values and offset allocations
Offset
PAD set 0 PAD set 1
0
0dB –7db
1
2dB –8db
2
3dB –9db
3
4dB –10db
4
5dB 0.6db
5
6.1dB 7db
6
8dB 9db
7
–1dB 10db
8
–3dB 11db
9
–4dB 12db
A idle code, 7F 3db
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.