PairGain 150-1236-54, Руководство пользователя

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Section 150-319-254
Revision 02
Page 2
A. GENERAL
1. INTRODUCTION
1.01 PairGain's HiGain Line Units Model ELU-
319, Lists 5D and 6D (Figure 1), are the
Public Exchange side of a repeaterless G.703
transmission system. When used with an ERU-412
HiGain Remote Unit (ERU), the system provides
2.048 Mbps transmission on two unconditioned
copper pairs. The “D” designation in the list number
indicates that this line unit can be used in doubler
applications to line power one doubler and one ERU
remote unit or two doublers. This is in contrast to
the ELU-319 List 5 and 6 which can only line power
one doubler or one ERU remote unit. The HiGain
system uses HDSL (High-bit-rate Digital Subscriber
Line) transmission technology as recommended by
Bellcore TA-TSY-001210. HiGain complies with TR-
TSY-000063 (Network Equipment Building System
(NEBS) Generic Equipment requirements) and TR-
TSY-000499 (Transport System Generic
Requirements–TSGR) common requirements.
1.02 Revision History of this practice.
Revision 02—February 22, 1996
a) Numerous updates to tables, figures,
also screen captures to include HiGain
Doubler EDU-451.
1.03 The ELU-319 is compatible with the
PairGain 22-slot HMS-318 shelf and the
associated G.703 HiGain connector panel HCP-322.
1.04 ELU-319 Product Family:
•
List 5D: 75-ohm G.703 Impedance
•
List 6D: 120-ohm G.703 Impedance
1.05 ELU-319 Issue 1 features:
•
-130V dc or -200V dc line power for
ERU-412 or EDU-451
• •
Optimal symmetric or ?symmetric HDSL
line voltage
•
Four-digit front panel display for HDSL
signal/noise (S/N) margin, configuration,
and alarms
•
RS-232 maintenance port
•
Non-volatile configuration memory
•
Front panel splitting and bridging access to
G.703 interface
•
Lightning and power cross protection on
HDSL interfaces
•
1040 kbps full-duplex two-bits one-
quaternary (2B1Q) HDSL transmission on
each of two pairs
•
Front panel status-indicating light-emitting
diode (LED) indicator
•
On / Off front-panel display power cycling
•
G.703 Loss of Signal (LOS) detector (125
consecutive zeros)
•
Margin threshold alarm
•
Single step default setting option
•
Circuit ID option
•
Improved tolerance to cable noise
•
Line powers two EDU-451 doublers or one
EDU and ERU.