Special Loopback Commands - ADC PAIRGAIN HiGain HDSL2 Manual

Testing

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 maintenance terminal System Settings screen (see
Table 6 on page 21) or by using the MODE and SEL buttons (see
is activated, other loopback commands can be sent by a test set connected to the craft port of the H2TU-C or
H2TU-R (see Table 22 on page 54
A2LB through A4LB are special, addressable, repeater loopback modes that are supported by the H2TU-C-231.
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 differs from A4LB in that A3LB supports the additional (1-in-6) SMJK loopback command.
50
and Table 23 on page 57 for list of SPLB commands).
April 21, 2000
152-231-115-03, Revision 03
Figure 26 on page 53). Once a loopback mode
H2TU-C-231 List 1E