Self-Loopback Test - Mitsubishi Electric QJ71LP21 Reference Manual

4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION

4.7.1 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.
(1) Connect the IN and OUT terminals of the QJ71LP21/QJ72LP25 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/QJ72BR15 network module (for the coaxial bus system).
For QJ71LP21/QJ72LP25
(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/QJ72LP25 at 25Mbps.
The self-loopback test is selected.
(3) Power on the target station.
The self-loopback test is executed; check the execution status on the network
module display.
During the test, the T.PASS LED flashes and the test is determined to have
completed normally when it flashes 20 times.
If the test is abnormally completed, the ERR. LED flashes.
Before test
⇒
T.PASS : Off
When an error occurs, the contents of the error should be checked with GX
Developer. The faulty area can be examined by replacing the cable.
REMARK
In the MELSECNET/H, a link refresh is executed even when the module is offline.
Thus, the user can check the testing status and the result with GX Developer or a
sequence program using the special link registers.
Host communication status
Cause of communication interruption SW0048
Offline test status on requesting side SW00AC
Offline test results on requesting side SW00AD
For details on how to check the error contents, see Chapter 8.
If two or more modules are installed, the testing status and the result of each module
can be checked by adding 200
For QJ71BR11/QJ72BR15
(coaxial bus system)
Connect IN
and OUT
During test Normal completion of test
⇒
: Flashing : Normal completion of test after 20 flashes
(approximately 10 s)
Abnormal completion of test
ERR. : Flashing
SW0047
to the corresponding device number.
H
MELSEC-Q
Connect terminal
resistors
1F : Offline test
2 : Offline test
7 : Self-loopback test
0 : Normal
1 or larger : Error code
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