Items Checked When Data Link Cannot Be Performed On A Certain Station - Mitsubishi Electric MELSEC Q Series Reference Manual

8 TROUBLESHOOTING

8.2.5 Items checked when data link cannot be performed on a certain station

Check item
Monitor the transmission status of each station.
Is the network module of the faulty station normal?
Was the loop error caused by the network module
or the data link cable?
Are the remote master station's parameters
correct?
Are the control station's parameters normal?
Are the switch settings of the network module
correct?
Has any data link cable been disconnected?
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Perform network monitoring of the network diagnostics of GX Developer, check for any
abnormally communicating station and check the loop status. Also, check whether or
not data linking is stopped.
In case of an optical loop system, check the line condition and transmission status of
each station as well, using the loop test of GX Developer's network diagnostics.
Check whether an error or problem has occurred in the CPU module and network
module of the faulty station.
Check whether or not the network module works normally with the self-loopback test of
the offline tests.
Check whether or not the data link cable is normal with the loop test of the offline tests.
Check that the total number of link stations is set to the largest number of the
connected stations or more, and check that the stations that cannot communicate are
designated as reserved stations.
Read the network parameters from the faulty station's CPU module and check that the
network settings such as the network type, start I/O number and network number are
correct.
Check the station number setting switch and the mode setting switch.
Perform the network monitoring or loop test in Network diagnostics of GX Developer to
check the wiring status.
Checking procedure
MELSEC-Q
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