Items Checked When Data Link Is Disabled By Resetting Or Powering Off A Station; Items Checked When Cyclic Data Is 0 By Resetting Or Powering On A Station - Mitsubishi Electric MELSEC Q Series Reference Manual

8 TROUBLESHOOTING

8.2.3 Items checked when data link is disabled by resetting or powering off a station

Check item
Is the cable wired properly?
Are the cables disconnected?
Are the switches of the network modules on all
stations set in the correct position?
Is the setting of the link monitoring time sufficient?

8.2.4 Items checked when cyclic data is 0 by resetting or powering on a station

Check item
Is the send range latched?
Is the block data assurance per station of cyclic
data set?
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Check the wiring status with GX Developer's network diagnostic loop test.
(Refer to Section 4.10.1.)
In the case of the coaxial bus system, check the coaxial connector connection on each
station and connections between the coaxial cables and coaxial connectors.
Check the status of each station to see whether the entire system is faulty or a specific-
station is faulty, and locate the faulty area.
Make sure that the mode setting switches of the network modules on all stations are in
the same position.
Set the link monitoring time to the maximum value and check whether or not data
linking is possible. If the "L ERR" LED of a normal station is lit, check the TIME error
with the GX Developer's network diagnostics.
POINT
Do not reset stations which are adjacent each other an optical loop system
(adjacent stations on the wire) simultaneously (resetting by the reset switch of the
remote I/O station or resetting by the key switches of the programmable controller
CPUs of the remote master station and remote sub-master station). Otherwise,
data link may not be able to be established.
If initialization and so on is necessary on adjacent stations simultaneously, turn off
and on the power supply.
Check whether B/W device in the send range is latched by latch setting of the CPU
parameter.
Check whether the block send data assurance per station is set.
POINT
A network module may send the initial value 0 in LB/LW data even B/W device in
the send range of the CPU parameter is latched.
By setting the block send data assurance per station prevents cyclic data from
being 0 since LB/LW data is sent after link refresh.
Checking procedure
Checking procedure
MELSEC-Q
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