ADTRAN DS3 NIU3 PM, Установка и эксплуатация

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2 Issue 5, February 2011 61213075L2-5E
Revision History
This is the fifth issue of this practice. This revision
updates the Guidance Troubleshooting information.
Description
The NIU3 PM resides at the demarcation point next to
customer premises equipment and can be housed in a
standalone enclosure, a 3-unit shelf, or a 12-unit shelf.
A loopback can be initiated at the customer interface
toward the network by either of the following methods:
• Remotely from the Test Center or Central Office
(CO).
• Locally from the NIU3 PM front panel
LBK SEL
pushbutton. Refer to Initiating Loopback with LBK
SEL Pushbutton on page 26 for details.
• Through the RS-232 (DB-9) craft interface.
The NIU3 PM is designed to loopback test data origi-
nating at the Test Center or the CO and responds to
commands inserted into the data stream by a test head
or portable test set. The loopback can isolate problems
located on the customer side of the demarcation point,
thus eliminating the need for an immediate trouble-call
dispatch. The NIU3 PM is transparent to data trans-
mission during normal operation. If the NIU3 PM fails,
is removed from its housing, or a flash upgrade is in
progress, the housing bypass relays (ADTRAN patent
pending configuration) ensure circuit continuity to
maintain data flow between the network and the
customer. A front panel LED on the NIU3 PM provides
notification of failure.
Figure 2 illustrates a circuit
diagram of the NIU3 PM in a SONET-based DS3
network.
Features
The NIU3 PM supports the following features and
functions:
• Enclosures:
– 12-slot shelf (P/N 1212078L1)
– 3-slot shelf (P/N 1212073L1)
– Standalone housing (P/N 1212070L1)
• DS3 C-Bit and M13 framing or unframed
• Bypass relays ensure virtually uninterrupted data
transmission during card failure, removal, or power
loss
• BNC network and customer connections
• Loopback in response to FEAC and in-band M13
codes
• Midsize flush-mounted jacks for nonintrusive
monitoring in both network and customer directions
• Recessed front panel pushbutton loopback control
• Performance and status information reports via DS3
network performance report messaging (NPRM)
• 50-character scratch pad
• RS-232 craft interface
• Loss of signal detection and notification
• 20, 60, 120-minute, and 24-hour test time out
• ±24 VDC or –48 VDC power for standalone or
shelf enclosures
• 120 VAC independent power options
• Dual power feeds in shelf configuration
• Internal test pattern generation/detection
• dBdsx measurement
• Performance history displays for intervals of 15
minutes, 60 minutes, 24 hours, and 30 days
• Customer transmit level setting
• Comprehensive troubleshooting screens including
receive level and frequency offset warnings
Figure 2. DS3 NIU3 PM Loopback Diagram