Self-Loopback Test - Mitsubishi Electric Q Series Reference Manual

4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION

4.5.1 Self-loopback test

1
MODE
RUN MNG
T.PASS D.LINK
SD RD
ERR. L ERR.
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This test checks the hardware of a standalone network module, including the
send/receive circuit and cable of the transmission system.
POINT
To perform the self-loopback test, be sure to connect the cable or terminal resistor.
Do not connect or disconnect the cable or terminal resistor during execution of the
test. (Doing so will result in test failure.)
(1) Connect the OUT and IN terminals of the QJ71LP21 network module (for the
optical loop system) with an optical fiber cable.
Connect a terminal resistor to both of the F-type connectors for the QJ71BR11
network module (for the coaxial bus system).
For QJ71LP21
(optical loop system)
IN
OUT
(2) Set the mode setting switch of the network module to "1". Set it to "5" when
using the QJ71LP21-25 at 25Mbps.
The self-loopback test is selected.
(3) Switch power on.
The self-loopback test is executed; check the execution status on the network
module display.
The T. PASS LED flashes during the test.
When the T. PASS LED flashes 20 times or more and if the ERR.LED does not
flash, this condition indicates normal completion.
If the test is abnormally completed, the ERR. LED flashes.
Upon detection of an error, the test will be terminated (abnormal termination).
Before test
⇒
T.PASS : Off
If an error is detected in the QJ71LP21 (for the optical loop system), check the
error in GX Developer and replace the cable to identify a faulty part.
For an error in the QJ71BR11 (for the coaxial bus system), check the error in GX
Developer and replace the terminal resistor to identify a faulty part.
For QJ71BR11
(coaxial bus system)
Connect IN
and OUT
During test Normal completion of test
⇒
: Flashing : Flashing 20 times (approx. 10 seconds) or
more
Abnormal completion of test
ERR. : Flashing
MELSEC-Q
Connect terminal
resistors
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