Mitsubishi QJ71DN91 User Manual page 27

3 SPECIFICATIONS
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(3) Reading the communication error information
PLC CPU
TO
SET Y12
FROM
X02 X05
FROM
X05
X02
Message communication
completion
The status of each slave station is stored during I/O communication.
1) The TO instruction of the sequence program sets to read the
communication error information in the "message communication
command" area of the buffer memory.
2) When the message communication request (Y12) is turned ON by the
sequence program, the error information of the applicable slave node
that has been accumulated in the QJ71DN91 is read and processed as
follows:
• The error information of the slave node that was set by the "message
communication command" area is stored in the "message
communication data" area of the buffer memory.
• The processing result of the message communication is stored in the
"message communication result" area of the buffer memory.
3) When the processing result is stored in the "message communication
result" area of the buffer memory, the message communication
completion (X02) is automatically turned ON.
4) The communication error information of the slave node, which is stored
in the "message communication data" area of the buffer memory, is
loaded onto the PLC CPU by the FROM instruction of the sequence
program.
5) If the message communication error signal (X05) is turned ON, the
FROM instruction reads the contents of the "message communication
result" area, and the cause of the error is verified.
QJ71DN91
0110
H
Message
1)
communication
command area
011F
H
Message
2)
communication
request
Slave
information
storage area
0120
H
5)
Message
communication
result area
012F
H
0130
H
Message
communication
data area
01A7
H
3)
Message
communication
complete
4)
MELSEC-Q
Slave node (MAC ID)
I/O
Class 1
communication
Instance
Attribute
Attribute
Instance
2)
Attribute
Attribute
Attribute
Class
Instance
Attribute
Attribute
Attribute
Instance
Attribute
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