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MELSEC-Q
10 TROUBLESHOOTING
10.1 Problem Identification
This section explains checking procedures and actions to be taken when a problem
occurs.
10.1.1 Checking the LEDs
NS LED lit green
or flashing green?
Problem occurred
Mode switch set in 0 to 8?
Set Mode switch in range of 0 to 8
and reset.
Yes
MS LED lit green?
(MS LED is off.)
Power on the module.
NS LED lit?
Turn on the network power (24V).
NS LED lit red?
Check if:
Node No. is within the range of 0 to 63.
The same node No. exists on the network.
The same communication speed is set for
the entire network.
Terminating resistors are connected to both ends of
the trunk line.
Check for an error code.
If the above check results are normal, check the entire
network condition such as noise or installation.
ERR.LED lit?
Set I/O Communication Request (Y11) to
on
.
NS LED flashing red?
I/O communication with one or more
slave nodes has failed.
Check 1B1H "Error Information for
Master Function" or 601H "Error
Information for Slave Function"
in the buffer memory for an error code,
and take corrective actions.
Parameter error has occurred.
Check 1B1H "Error Information for
Master Function" or 601H "Error
Information for Slave Function" in
the buffer memory for an error code,
and take corrective actions.
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
No
No
No
10
Summary of Contents for QJ71DN91
Page 1: ...DeviceNet Master Slave Module User s Manual QJ71DN91 GX Configurator DN SW1D5C QDNU E ...
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