Generic Loopback Commands; Special Loopback Commands - ADC HiGain H2TU-C-202 Manual

Testing

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) towards the network. In addition, these inband codes loop up CREM (6-in-7)
or CLOC (5-in-7) towards the customer. Either loopup condition can be terminated (looped down) with the 3-in-5,
SMJK loopdown 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 T1 input from the CI.
Figure 29 on page 45
HDSL2 generic loopback commands. See
when using the GNLB mode.
Table 22. Summary of HiGain HDSL2 Generic Loopback Codes and Activation Methods
Loopback Code
NLOC 1111000
4-in-7
NREM 1110000
3-in-7
CLOC 1111100
5-in-7
CREM 1111110
6-in-7

Special Loopback Commands

In addition to the GNLB loopback command mode, a HiGain HDSL2 system can be configured for one of three
special loopback command modes. These are selected from the ADC Options in the maintenance terminal Config
menu, ADC Options screen (see
commands can be sent by a test set connected to the craft port of the H2TU-C or H2TU-R (see
and Table 24 on page 52
A2LB through A4LB are special, addressable, repeater loopback modes that are supported by the H2TU-C-202.
These loopback modes provide the HiGain HDSL2 system with sophisticated maintenance and troubleshooting
tools. A2LB is patterned after the Teltrend addressable T1 repeater loopbacks. A3LB and A4LB are patterned
after the Wescom addressable T1 repeater loopbacks.
All three SPLBs have been enhanced to handle the specific requirements of the following HiGain HDSL2
customers:
• A2LB (Teltrend) = Southwestern Bell
• A3LB (Wescom) = New England Telephone, Bell Atlantic
• A4LB (Wescom Mod 1) = New York Telephone
A2LB can be configured to do one of the following:
• Block the arming code (after 2 seconds) from exiting the H2TU-C into the network, and replace it with the
AIS code.
• Unblock the AIS code by executing the Far End Activate code.
A3LB and A4LB test procedures are identical.The SMJK loopup and loopdown commands are controlled by the
LPBK setting.
46
summarizes the available loopbacks in the system, and
"GNLB Test Procedures" on page 48
Description
DSX-1 signal is looped back to the network at the H2TU-C.
DSX-1 signal is looped back to the network at the H2TU-R.
DS1 signal from the customer is looped back to the
customer at the H2TU-R.
DS1 signal from the customer is looped back to the
customer at the H2TU-C.
Table 6 on page
for list of SPLB commands).
February 28, 2001
17). Once a loopback mode is activated, other loopback
LTPH-TP-1005-02, Issue 2
Table 22 summarizes the HiGain
for the test procedures that apply
Method of Activation
Test Set Craft Port
X X
X X
X X
X X
Table 23 on page 50
H2TU-C-202 List 3E