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Once the Model 2073 is properly configured and installed, it
should operate transparently. This sections describes power-up, read-
ing the LED status monitors, and using the built-in loopback test
modes.
5.1 POWER-UP
To apply power to the Model 2073, first be sure that you have
read Section 4.3, and that the unit is connected to the appropriate
power source. Then power-up the unit using the rear power switch.
Figure 5 (below) shows the front panel location of each LED. A
description of the each LEDs funtion is below Figure 5.
Figure 5. Model 2073 Front Panel
5.2 LED STATUS MONITORS
The Model 2073 features13 front panel LEDs that monitor power,
the DTE signals, network connection and test modes. The figure
below shows the front panel location of each LED. Following the fig-
ure below is a description of each LEDs function.
TD & RD
Glows yellow to indicate an idle condition of Binary
“1” data on the respective terminal interface sig-
nals. Green indicates Binary “0” data
CTS
Glows green to indicate that the Clear to Send sig-
nal from the modem is active.
CD
Glows yellow if no carrier signal is being received
from the remote modem. Green indicates that the
remote modem’s carrier is being received.
RTS
Glows green to indicate that the Request to Send
signal from the terminal is active.
ER
- flashes once to indicate that a CRC error has
occurred (during normal operation) or bit errors
have occurred (during 511/511E tests).
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TM
glows yellow to indicate that the Model 2073
has been placed in Test Mode. The unit can be
placed in test mode by the local user or by the
remote user.
SYNC
Glows green to indicate a valid G.703 connection.
5.3 TEST MODES
The Model 2073 offers two V.54 loop diagnostics: Local Analog
Loopback and Remote Digital Loopback. These tests can be activated
physically from the front panel, or via signals on the
QuickConnect
TM
interface.
5.3.1 Operating Local Analog Loopback (LAL)
The Local Line Loopback (LAL) test checks the operation of the
local Model 2073, and is performed separately on each unit. Any data
sent to the local Model 2073 in this test mode will be echoed
(returned) back to the user device (i.e, characters typed on the key-
board of a terminal will appear on the terminal screen).
Figure 6. Local Line Loop
To perform a Local Analog Loopback test, follow these steps:
1. Notify the G.703 Service provider that you wish to perform a
G.703 Loop test.
2. Move the front panel toggle switch UP to “Local.
3. Verify that the data terminal equipment is operating properly
and can be used for a test.
4. Perform a V.52 BER (bit error rate) test as described in Section
5.3.3. If the BER test equipment indicates no faults, but the
data terminal indicates a fault, follow the manufacturer’s
checkout procedure for the data terminal. Also check the
interface cable between the terminal and the Model 2073.
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