Verilink 2000 (34-00182) Product Manual - Manual (Page 33)

Front Panel Testing 3-3
13 TST: This LED lights continuously during a Far or a Local test. It flashes while
loopback codes are transmitted at the start of a Far test and while unloop codes are
transmitted at the end of a Far test.
14 ERR: This LED lights for one second when BERT pattern errors are received
during a Far test.
15 Test Switch: This switch (FAR /LOC) is used for local testing. Refer to Test
Switch for more information.
16 Test Access Jacks: These six bantam test jacks are provided for access to the T1
line on the DTE side of the CSU. Refer to Test Access Jacks for more
information.
17 Supervisory Port: The supervisory jack provides direct terminal access to control
the unit and gather status/facility performance data. Refer to Supervisory Port.
18 Pattern Select: This switch determines the BERT pattern sent by the CSU when
the Test switch (item 15) is in the FAR position. Refer to BERT Pattern Select.
Front
Panel
Testing The previous section gave a brief description of each front panel control and LED
indicator. This section explains the front panel test functions. Testing may also be
performed using software control from the EM8000 Network Manager, the
Terminal Interface program, or the 8100A Site Controller.
Test
Switch
This switch (labeled FAR/LOC) is used for local testing. When in the Far position,
the unit sends five seconds of IBLC (inband loop codes), then switches to the test
pattern selected by the Pattern Select rotary switch. When transmitting IBLC, the
test LED blinks. When transmitting a test pattern, it lights continuously. The ERR
LED lights for one second when a bit error or sync loss is detected.
When the Test switch is returned to the normal, center position, the unit sends five
seconds of loop down code (100) and then returns to its normal operating mode.
When the Test switch is in the Local position, the unit performs a local loop. The
LLB and Test LEDs are lit.
Test
Access
Jacks
Six bantam test jacks are provided for access to the T1 line on the DTE side of the
CSU. Two are used for non-intrusive bridge monitoring of the line in both
directions (MON). Two are used to drop the line (DTE) and two are used to insert
into the line in both directions (NET). Jacks are customarily used to inject and
receive T1 signals using a T1 test set. Figure 3-2 shows the front panel access
jacks. Figure 3-3 shows where the jacks connect in the circuit.
Receive signal
from the DTE
Transmit signal
to the network
Transmit signal
to the DTE
Receive signal
from the network
Monitor signal
from the network
Monitor signal
from the DTE
Figure 3-2 Front Panel Access Jacks