5.3 LOOPBACK TEST (LAL)
The Model 2703 is equipped with a Local Analog Loopback (LAL)
mode to assist in evaluating the operation of the local Model 2703.
Any data sent to the local Model 2703 in this test mode will be echoed
(returned) back to the user device. For example, characters typed on
the keyboard of a terminal will appear on the terminal screen. To per-
form a LAL test, follow these steps:
A.
Activate LAL by moving the front panel toggle switch UP and
holding it in the “Loopback” mode. The “Loop” LED should
glow. Once LAL is activated, the Model 2703 transmit output
is connected to its own receiver.
NOTE: The front panel switch is spring loaded, so it will
return to “Normal” operating mode when pressure is released.
To put the Model 2703 in
continual
loopback mode, for the
purpose of performing a BER test, move DIP switch S1-8 to
the “ON” position (see Section 3.1).
B.
Verify that the data terminal equipment is operating properly
and can be used for a test. If a fault is indicated, call a tech-
nician or replace the unit.
C. Perform a BER (bit error rate) test on each unit. If the BER
test equipment indicates no faults, but the data terminal indi-
cates a fault, follow the manufacturer’s checkout procedures
for the data terminal. Also, check the interface cable between
the terminal and the Model 2703.
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APPENDIX A
PATTON MODEL 2703 SPECIFICATIONS
Network Interface:
G.703
Network Rate:
2.048 Mbps
Network Connectors:
Two BNC (75 Ohm) and one
modular RJ-45 connector (120
Ohm)
Terminal Interface:
EIA RS-530 (V.36/RS-422), X.21,
V.35 on UD-26
Terminal Rate:
2.048 Mbps;
1.024 Mbps, 512 kbps, 256 kbps
Diagnostics:
Loopback Test
Indicators:
LEDs for power, network, master
clock and loopback test
Clocking:
Internal or network (receive
loop)
Receiver Sensitivity:
-10 dB (0dB = 2.4V)
Power:
115/230 VAC (switch selectable),
50/60 Hz; 85-265 VAC, 50/60 Hz
(universal input option); 48 VDC
(option)
Temperature Range:
0-60°C (32-140°F)
Altitude:
0-15,000 feet
Humidity:
5 to 95% non-condensing
Dimensions:
7.3” x 6.6” x 1.62” (185mm x
168mm x 41mm)
Weight:
2.02 lbs.
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