Loopback Operation; Generic Loopback Commands - ADC HiGain H2TU-C-388 List 1E User Manual

Testing
L O
OOPBACK PERATION
HiGain HDSL2 has a family of loopback options for analyzing circuit functionality. The loopback signal is
transmitted and returned to the sending device for comparison. This allows you to verify the integrity of the
HDSL2 channels to the H2TU-C, the H2TU-C DSX-1 interface and the DS1 channels to the customer. Loopback
options include:
• Generic Loopback (GNLB), including the SmartJack (SMJK) option, as described in
Commands" on page 46
•
Special Loopback (SPLB) options, as described in
following command tables:
–
Addressable Repeater Loopback commands: A2LB, as described in
–
Addressable Repeater Loopback commands: A3LB, A4LB, as described in
Loopback commands can be initiated by:
•
Selecting the loopback type using the MODE and SEL buttons on the H2TU-C front panel or the Manual
Loopback button on the H2TU-R
•
Selecting the loopback type from the Monitor Menu when connected to the craft port of the H2TU-C or
H2TU-R
• Entering the loopback code into the test equipment connected to the H2TU-C or H2TU-R
HiGain HDSL2 only supports one active loopback, however, SmartJack loopback can be present
along with one other network loopback.

Generic Loopback Commands

The HiGain HDSL2 Generic Loopback (GNLB) commands allow you to use inband codes to loop up either
NLOC (4-in-7) or NREM (3-in-7) toward the network. In addition, these inband codes loop up CREM (6-in-7) or
CLOC (5-in-7) toward the customer. Either loopup condition can be terminated (looped down) with the 3-in-5,
SMJK loop-down code. All inband codes must be present for at least 5 seconds before the HiGain HDSL2 system
responds. TLOS is a logic loopback caused by loss of the DS1 input from the CI.
Figure 24 summarizes the available loopbacks in the system, and
HDSL2 generic loopback commands.
the GNLB mode.
Activate loopback using
one of the following:
• MODE/SEL pushbuttons
• Maintenance Terminal
• Test Set
46
"GNLB Test Procedures" on page 50
NLOC CREM
H2TU-C
Network
Figure 24. Loopback Summary
April 21, 2000
"Special Loopback Commands" on page 48
Table 22 on page 52
Table 21 on page 47
details the test procedures when using
Activate loopback using
one of the following:
• LBK pushbutton
NREM
• Maintenance Terminal
SMJK CLOC
• Test Set
TLOS
H2TU-R
Customer
Premises
152-388-115-03, Issue 03
"Generic Loopback
and the
Table 23 on page 55
summarizes the HiGain
H2TU-C-388 List 1E