Chapter 3. Test Modes
3-6
DSU 56/64 User Manual
61200062L1-1
LOOP ONLY TEST (RT)
The
L
OOP
O
NLY
test or
R
EMOTE
L
OOPBACK
test (RT) is used to test
the loop interface and a major portion of the DTE interface of the
local DSU 56/64 from the remote site over the actual digital data
circuit.
For the
L
OOP
O
NLY
test, the network receive data is looped to the
network transmit data inside the DTE interface section of the DSU
56/64. The physical DTE interface is ignored for this test. The
L
OOP
LED flashes during initialization of the test and turns on solid once
the test is in progress. Figure 3-4 illustrates the loopback point and
the signal paths for this test.
Figure 3-4. Loop Only Test Diagram
To initiate the
L
OOP
O
NLY
test
,
perform the following steps:
1. Press
S
ELECT
four times to turn on the
L
OOP
test indicator.
2. Press
T
EST
while this test indicator is on.
3. To terminate this test, press
T
EST
.
56/64 DSU
DTE
Receive
Interface
DTE
Transmit
Interface
Loop
Transmit
Interface
Loop
Receive
Interface
Loop
Only
TD
DTE or Test
Equipment
Interface
Network
Interface
RD
Loop TX
Loop RX
Содержание DSU 56/64
Страница 1: ...DSU 56 64 Data Service Unit User Manual Part Number 1200062L1 61200062L1 1E May 2001...
Страница 16: ...List of Figures xvi DSU 56 64 User Manual 61200062L1 1...
Страница 18: ...List of Tables xviii DSU 56 64 User Manual 61200062L1 1...
Страница 28: ...Chapter 2 Installation 2 6 DSU 56 64 User Manual 61200062L1 1...
Страница 38: ...Chapter 3 Test Modes 3 10 DSU 56 64 User Manual 61200062L1 1...