When Communication With The Master Node Cannot Be Performed (Using The Slave Function) - Mitsubishi QJ71DN91 User Manual

9 TROUBLESHOOTING
9.1.4 When communication with the master node cannot be performed (using the slave
function)
Communication with the master node cannot be
performed (when the NS LED is flashing in green or lit in red)
Is the mode switch set between 3 and 8?
Is the communication cable securely
connected to the QJ71DN91 connector?
Are there any duplicate slave station
I/O points of the slave function match with
Check the entire network status such
as noise and installation.
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Yes
Yes
Is the network power turned ON?
Yes
Is the communication speed
the same in all nodes?
Yes
Is a terminal resistor connected?
Yes
numbers with the QJ71DN91?
No
Does the number of
the parameter setting of the
master station?
Yes
Are the parameters of
the master station set for polling
and UCMM support (group 3)?
Yes
Is the I/O communication
request Y11 turned ON?
Yes
Is an error code generated?
No
No Reset by setting the mode switch between 3 and 8.
No
Connect the communication cable securely.
No
Turn ON the network power.
Set the same communication speed in all
No
nodes.
No
Connect a terminal resistor.
Set non-duplicate node number.
Yes
Match the number of I/O points with that of the
No
master station.
Set the parameters of the master station for
No
polling and UCMM support (group 3).
No Turn ON the I/O communication request.
No
Take an action according to the error code.
MELSEC-Q
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