Checking Online For Reverse Optical Fiber Cable Connection - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

8 TROUBLESHOOTING

8.2.11 Checking online for reverse optical fiber cable connection

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This section explains the checking procedure for incorrect optical fiber cable
connection (IN-IN, OUT-OUT) during online and the link special registers (SW009C to
SW009F) used for the check.
Unlike the loop test, the checking procedure given in this section allows a check
without stopping a data link.
If incorrect cable connection is found, correct the wiring after shutting off all phases of
the system.
POINT
Before starting the check given in this section, make sure that the following
conditions are satisfied.
If these are not satisfied, conduct a loop test to make a check.
Multiplex transmission function is not used.
The optical fiber cables have no breaks. (Both the forward and reverse loop
cables are normal.)
There are no stations having data link error (power off, MELSECNET/H module
failure).
(1) Checking procedure
Follow the procedure given below to check for incorrect optical fiber cable
connection (IN-IN, OUT-OUT) during online.
MELSEC-Q
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