Mitsubishi Electronics QJ71DN91 ユーザーズマニュアル

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MELSEC-Q

9 TROUBLESHOOTING

9.1.3 When communication with a specific slave node cannot be performed (using the

master function)

Communication with a specific slave node cannot be

performed (when the NS LED is flashing in red)

Is the slave node power turned ON?

Is the communication cable securely

connected to the slave node?

Are the parameters written?

Create and write correct parameters.

Take an action according to the error code.

Turn ON the slave node power.

Connect the communication cable securely.

Is the communication speed the

same as that of other nodes?

Set the same communication speed as that of
other nodes.

Are all node numbers unique?

Set non-duplicate node numbers.

Is the slave node set in a parameter?

Is the actual node

number the same as the node number

in a parameter?

Is a reserved node not set?

Does the specified

connection type match with the slave

node specification?

Do the UCMM presence

and message group match with the slave

node specification?

Does the setting value

of the watchdog timeout action match with the

slave node specification?

Does the I/O configuration

in a parameter match with the I/O configuration of

the actual slave node?

Is the production inhibit time not too short?

Is the production inhibit time not too long?

Is an error code generated?

Check the entire network status such as noise
and installation.

Yes