Chapter 5 - Troubleshooting and Diagnostics HCD-E1
Installation & Operation Manual
5-22 Diagnostic Tests 01/01/01 08:15
LP L LINE
These local loopbacks on the HDSL lines are performed in the HDSL framer,
as shown in Figure 5-1. Test signal is provided either by the equipment
connected to one of the inputs, which must receive its own transmissions
without errors, or by applying the BERT test.
This test fully checks the connections to the equipment connected to the
local E1 sublink and/or data channels, as well as the circuits of the local unit.
Figure 5-1 LP LINE Loopback
Notes
1. This loopback can be activated only from the unit configured as central.
2. While this loop is active, HCD-E1 loses HDSL synchronization.
LP L HRPT
This local loopback on the HDSL repeater is performed as shown in
Figure 5-2. The loopback can be performed only from the HCD-E1 unit
configured as central.
This test fully checks the connections to the equipment connected to the
local E1 sublink and/or data channels of the HCD-E1 unit configured as
central, all the circuits of both HCD-E1 and H-RPT, and the transmission
path connecting the two units.
During the loopback, the remote unit continues to receive data sent from
the central unit.
Figure 5-2 H-RPT Local Loopback
