10 - 17 10 - 17
MELSEC-Q
10 TROUBLESHOOTING
Protocol
Error code
(Hexa-
decimal)
Error
Error Contents
Signal
name
Corrective action
MC
Non
Proce-
dure
Bidire-
ctional
716FH Device error
โข A nonexistent device was designated.
โข Device that cannot be specified by the
corresponding command was designated.
PRO
โข Check and correct the external
device transmit message and
restart data communications.
7170H โข Number of access points exceeded the range. PRO
7171H โข A device that cannot be designated was designated. PRO
7172
H
A compatible 1C
frame error
โข Written number of monitoring points is incorrect. For
example, [0] was designated.
PRO
โข Check and correct the external
device transmit message and
restart data communications.
7173H
Monitor data write
error
โข Monitor data was written for a CPU other than a
Q/QnACPU using QnA compatible 2C/3C/4C frame.
PRO
โข Write the monitor data and use
the A compatible 1C frame to a
CPU other than a Q/QnACPU.
7E00H
to
7E05
H
System error โข The OS of the Q series C24 detected some error. โ ( 1)
7E06H
Buffer memory
address setting
error
โข Transmit/receive buffer memory addresses are in
the special applications area.
๏ฃง
โข Change the buffer memory
addresses so that they are outside
the special applications area.
7E07H
to
7E0A
H
System error โข The OS of the Q series C24 detected some error. โ ( 1)
7E40H Command error
โข A nonexistent command or subcommand was
designated.
PRO
โข Check and correct the external
device transmit message and
restart data communications.
7E41
H
Data length error
โข A data length exceeding the number of points that
can communicate during random read/write was
designated.
PRO
โข Check and correct the external
device transmit message and
restart data communications.
7E42
H
Error count error
โข Number of requested points exceeds the range for
the command.
PRO
โข Check and correct the external
device transmit message and
restart data communications.
7E43
H
Device error
โข A nonexistent device was designated.
โข Device that cannot be specified by the
corresponding command was designated.
PRO
โข Check and correct the external
device transmit message and
restart data communications.
7E44H
Timer 1 time-out
error
โข A response message was not returned within the
response monitoring time (timer 1) monitoring time.
C/N
โข Make the timer 1 monitoring
time longer.
โข When accessing another
station's CPU, check if the
routing parameters match.
7E46H System error โข The OS of the Q series C24 detected some error. โ ( 1)
7E47
H
Continuous request
error
โข The next request was received before a response
message was returned for the preceding request.
PRO
โข Do not issue continuous
requests from the external
device.
โข Set the timer 1 monitoring time
to the external device time-out
time.
7E48
H
to
7E4C
H
System error โข The OS of the Q series C24 detected some error. โ ( 1)
7E4D
H
Error during data
transmission
โข Mode switching was executed during data
transmission.
CHn
ERR.
โข Make arrangements between
the target device and PLC CPU
so that mode switching is not
executed during data
transmission.
7E4E
H
System error โข The OS of the Q series C24 detected some error. โ ( 1)
7E4F
H
Device point count
error
โข Access point count is incorrect. PRO
โข Check and correct the external
device transmit message and
restart data communications.
7E50H
User frame No.
designation error
โข A user frame No. outside the range was designated. PRO
โข Check and correct the external
device transmit message and
restart data communications.
โข Recheck the frame No..
7E51
H
Unwritten user
frame error
โข An unwritten user frame No. was designated. PRO
โข Write the frame beforehand.
โข Change the frame No. and
restart data communications.
โข Recheck the frame No..