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MELSEC-Q
10 TROUBLESHOOTING
10.2 Error Code Tables
The following shows the error codes, error contents, and corrective action for errors
that are generated during communication between the Q series C24 and an external
device.
The signal name in the following table indicates the CH
side LED on status or
communication error status that is stored into buffer memory address 201
H
/202
H
when
an error occurs.
The CH
side LED on status and communication error status can be confirmed by GX
Developer's System monitor or GX Configurator-SC. (Refer to Section 10.1.1.)
For errors without a corresponding signal name entered to errors generated with the
MC protocol communication, “NAK” comes on.
10.2.1 Error code table
The following shows the error codes, error contents, and corrective action for errors
generated during communication using MC protocol (excluding A compatible 1C
frame), non procedure protocol, and bidirectional protocol.
("
" in the table is the error code when the target CPU is not a Q/QnACPU.)
Protocol
Error code
(Hexa-
decimal)
Error
Error Contents
Signal
name
Corrective action
MC
Non
Proce-
dure
Bidire-
ctional
3E8
H
to
3FFF
H
— (Error detected by the CPU) —
• See Troubleshooting of the
QCPU (Q mode) maintenance
and inspection user's manual
and take corrective action.
4000H
to
4FFF
H
— (Error detected by the CPU) —
• See Appendix of the QCPU (Q
mode) maintenance and
inspection user's manual
(details) and take corrective
action.
7101
H
7102
H
System error • The OS of the Q series C24 detected some error. — ( 1)
7103
H
PLC access error • Cannot communicate with the Q series C24 CPU. C/N
• Make the watchdog timer (timer
1) time longer.
• Check if the CPU can
communicate in communication
protocol No. "F".
7104
H
to
7116
H
System error • The OS of the Q series C24 detected some error. — ( 1)
7140
H
Request data error
• Number of request points exceeds the range for the
command.
• A word device was designated in a bit units
command.
• The last device No. exceeds the range.
Given device last No. > Designated head device
No. + Designated number of points
PRO
• Check and correct the external
device transmit message and
restart data communications.
7141H System error • The OS of the Q series C24 detected some error. — ( 1)
7142
H
Device name error
• A device that cannot be designated by the given
command was designated.
PRO
• Check and correct the external
device transmit message and
restart data communications.
7143
H
Device No. error • The head device No. is out of range. PRO
• Check and correct the external
device transmit message and
restart data communications.
7144
H
Monitor data write
error
• Monitoring was requested before the device to be
monitored was written.
PRO
• Write the device to be monitored
before issuing a monitor request.
7145
H
Monitor PLC No.
error
• The written PLC No. and PLC No. in the monitor
request are different.
C/N • Rewrite the monitor data.
7146
H
Monitor CPU model
name error
• The written CPU model name and the CPU monitor
name in the monitor request are different.
C/N • Rewrite the monitor data.
7147
H
Written number of
monitoring points
overrun error
• The written number of monitoring points exceeds
the designated range.
PRO
• Check and correct the external
device transmit message and
restart data communications.