Loopback operation, Generic loopback commands, Loopback summary – ADC H2TU-C-231 User Manual
Page 51: Oopback, Peration
LTPH-UM-1109-01, Issue 1
Testing
H2TU-C-231 List 2
January 9, 2002
43
L
OOPBACK
O
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) options, including the SmartJack (SMJK) option (see
)
•
Special Loopback (SPLB) options (see
“Special Loopback Commands” on page 45
) and the following
command tables:
–
Addressable Repeater Loopback commands: A1LB, A2LB, A5LB (see
–
Addressable Repeater Loopback commands: A3LB, A4LB (see
Loopback commands can be initiated by:
•
Selecting the loopback type using the MODE and SEL pushbuttons on the H2TU-C front panel or the manual
loopback (LBK) pushbutton 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 (exceptions are COLB and RULB) into the test equipment connected to the
H2TU-C-231 or H2TU-R.
Figure 27.
Loopback Summary
Generic Loopback Commands
The HiGain 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 DS1 input from the CI.
summarizes the available loopbacks in the system, and
on this page summarizes
the HiGain HDSL2 generic loopback commands.
Network
Customer
Premises
Activate loopback using
one of the following:
• Maintenance Terminal
• Test Set
• MODE/SEL pushbuttons
Activate loopback using
one of the following:
• Test Set
• LBK pushbutton
• Maintenance Terminal
H2TU-C
H2TU-R
NLOC
NREM
SMJK
TLOS
CREM
CLOC