Loopback Testing - ADC HDSL4 Quick Installation

L
OOPBACK
Initiate loopback testing from the maintenance menus or use the MODE and SEL
pushbuttons. Testing can also be initiated by using a test set to send inband codes
Refer to the user manual, document number LTPH-UM-1122-xx, for more information.
DSX-1
Network
NLOC
H4TU-C
Downstream
Loopback Inband Code Description
NLOC 1111000
NREM 1110000
CLOC 1111100
CREM 1111110
NDU1 110000
NDU2 111000
CDU1 111100
CDU2 111110
SMJK 11000
Loopdown 11100
Message
(b)
PWR FEED SHRT
(b)
PWR FEED GND
(b)
PWR FEED OPEN
SPNn-LOSW
LLOS
RLOS
LAIS
RAIS
LRAI
RRAI
xxx-LOF
xxx-DBER
PRMF
PRMN
(c)
xxxx-HBRx
(c)
xxxx-MALx
(c)
xxxx-LAx
(a) Front panel alarm messages are listed in order of priority. ALRM displays prior to any alarm message.
Pressing the LBK button initiates an Alarm Cutoff (ACO) message.
(b) Message displays repeatedly as long as the alarm condition exists and is not included in the priority order.
(c) The xxxx prefix denotes TUC, TUR, or a first or second doubler interface, upstream or downstream (DUxU
or DUxD, where x = Doubler 1 or 2). The single x suffix denotes Loop 1 or Loop 2.
To comply with the intrabuilding wiring requirements of GR-1089
CORE, Section 4.5.9, the shields of the ABAM-type cables that
connect the H4TU-C-388 List 1 DSX-1 output ports to the
cross-connect panel must be grounded at both ends.
T
ESTING
Span 1
CREM CDU1
NDU1
H4D1
*
When enabled, TLOS is an automatic loopback
that occurs with an LOS at the remote DS1 input.
Table 1. GNLB Loopback Commands
DSX-1 signal is looped back to the network at the H4TU-C.
DSX-1 signal is looped back to the network at the H4TU-R.
DS1 signal from customer is looped back to the customer at the H4TU-R.
DS1 signal from customer is looped back to the customer at the H4TU-C.
Signal is looped back to the network at H4D1.
Signal is looped back to the network at H4D2.
Signal from customer is looped back to the customer at H4D1.
Signal from customer is looped back to the customer at H4D2.
DSX-1 signal is looped back to the network at the H4TU-R SmartJack module.
Deactivates any of the above loopbacks.
Table 2. Front-Panel Alarm Messages
Description
A short between Loop 1 and Loop 2 of the HDSL4 pairs.
The HDSL4 loop is grounded.
A line-power open condition.
The HDSL4 loop has lost synchronization. The span closest to the network has
highest priority. (n = span number)
No signal is detected at the DSX-1 input to the H4TU-C.
No signal is detected at the DS1 input to the H4TU-R.
Line Alarm Indication Signal.
Remote Alarm Indication Signal.
An RAI alarm (yellow) from the Customer Premises Equipment (CPE) with an
error-free signal from the line unit or network. RAI signal is transmitted towards the
network.
An RAI alarm (yellow) from the CPE with errors from the line unit or network.
DS1 input does not contain the ESF or SF frame pattern setting of the FRMG option.
(xxx denotes either Transmission Unit Central Office [TUC] or Transmission Unit
Remote End [TUR]).
A system DS1 Bit Error Rate (DBER) alarm (xxx denotes either TUC or TUR).
H4TU-R Performance Report Messaging BER threshold exceeded at far end.
H4TU-R Performance Report Messaging BER threshold exceeded at near end.
A system HDSL4 Block Error Rate (HBER) alarm.
The margin on the HDSL4 loop has dropped below the threshold setting.
The attenuation on the HDSL4 loop has exceeded the maximum threshold value.
Span 3
Span 2
CDU2
NDU2
H4D2
(Table
NREM
Customer
SMJK CLOC
Premises
*
TLOS
DS1
H4TU-R
Upstream
(a)
1).