Product Manual - DM991 Series V Family - 204.4092.08
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Figure 25. DM991 - BERT Test on G.shdsl Interface
12.1.4. RDL Test
This test facilitates the verification of the link status and of the two data directions. The interface sends a
loopback request to the remote equipment. The remote detects the RDL request and sends a loop closing
confirmation signal. When the equipment that sent the request detects the answer, it goes into testing.
The remote device has the same behavior when in LDL test. In the terminal status menu, the remote side
shows the RX-LDR indication while the local side shows the TX-LDR indication. Figure 26 shows the
pattern generation in this interface.
It is also possible to simultaneously execute the BERT, eliminating the need for an external test-set and
locally testing the metallic link. To carry this test it is necessary to first activate the RDL and then the
BERT.
The equipment will remain on testing conditions until the key (in the case of DM991S/SE modems) or the
CT141 are deactivated.
Figure 26. DM991 - RDL Test on G.shdsl interface
12.2. E1 Interface Tests
12.2.1. LDL Test
This test helps the verification of the internal and external data link status. Two loopbacks are done. The
internal loopback makes the data coming from the G.shdsl interface to be retransmitted. The external
loopback makes the external data coming from the E1 tributary to return to it. Figure 27 shows the test
conditions
Figure 27. DM991 - LDL Test on E1 Interface
12.2.2. LAL Test
The LAL tests the analogue part of the interface circuits. The data transmitted through the E1 interface
returns to the modem interface and the data coming from the E1 is discarded.
The BERT of DM991 modems is generated with exact rate of line (minimum 192Kbit/s), except the
timeslot used for CAS, in which is sent mark (all bits equal 1). It is different of interfaces DM705 -
DSL1/DSL2/DSL8 where BERT is sent in accordance with the number of channels configured for the
interface (minimum 64kbit/s).
Summary of Contents for DM991C
Page 1: ...DM991 SERIES V DM991C DM991CE DM991S DM991SE PRODUCT MANUAL 204 4092 08 rev 08 Date 8 12 2008 ...
Page 66: ...Product Manual DM991 Series V Family 204 4092 08 66 Figure 31 LDL Test Converter Mode ...
Page 89: ...Phone 55 51 3358 0100 Support 55 51 3358 0122 Fax 55 51 3358 0101 www datacom ind br ...
