Mitsubishi Electric QJ71C24N User Manual page 339

11 TROUBLESHOOTING
Error code
Error
(Hexa-
decimal)
Error count error
7E42
H
Protocol setting data
write error
7E43 Device error
H
Timer 1 time-out
7E44
H
error
7E46 System error
H
Continuous request
7E47
H
error
7E48
H
to System error
7E4C
H
Error during data
7E4D
H
transmission
7E4E System error
H
Device point count
7E4F
H
error
User frame No.
7E50
H
designation error
Unwritten user
7E51
H
frame error
User frame
7E52
H
overwrite error
User frame access
7E53
H
data error
Modification allowed
7E54
H
error
User frame data
7E55
H
error
7E56 System error
H
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Description
 Number of requested points exceeds
the range for the command.
 Protocol setting data were written to the
Q series C24 that does not support the
pre-defined protocol communication.
 A nonexistent device was designated.
 Device that cannot be specified by the
corresponding command was
designated.
 The head device No. is out of range.
 A response message was not returned
within the response monitoring time
(timer 1) monitoring time.
 The OS of the Q series C24 detected
some error.
 The next request was received before a
response message was returned for the
preceding request.
 The OS of the Q series C24 detected
some error.
 Mode switching was executed during
data transmission.
 The OS of the Q series C24 detected
some error.
 Access point count is incorrect.
 A user frame No. outside the range was
designated.
 An unwritten user frame No. was
designated.
 A written frame No. overwrite request
was issued.
 A nonexistent command was
designated in a subcommand.
 Byte count exceeding the number of
bytes that can be requested was
designated.
 Flash ROM write allow/prohibit
designation from GX Configurator-SC is
set to OFF.
 At the switch setting on GX Developer,
modification allowed switch was set to
OFF.
 There is an error in the user frame
variable data.
 The OS of the Q series C24 detected
some error.
Signal
Corrective action
name
 Check and correct the external device
transmit message and restart data
communications.
 To use the pre-defined protocol
PRO
function, use a supported Q series
C24N. (Use the QJ71C24N(-R2/4)
whose first 5 digits of serial No. is
10122 or higher.)
 Check and correct the external device
PRO transmit message and restart data
communications.
 Make the timer 1 monitoring time
longer.
C/N
 When accessing another station's CPU,
check if the routing parameters match.

1
 Do not issue continuous requests from
the external device.
PRO
 Set the timer 1 monitoring time to the
external device time-out time.

1
 Make arrangements between the target
CHn device and programmable controller
ERR. CPU so that mode switching is not
executed during data transmission.

1
 Check and correct the external device
PRO transmit message and restart data
communications.
 Check and correct the external device
transmit message and restart data
PRO
communications.
 Recheck the frame No..
 Write the frame beforehand.
 Change the frame No. and restart data
PRO
communications.
 Recheck the frame No..
 Change the write destination to an
unwritten frame No.
PRO
 When overwriting, delete the given No.
beforehand.
 Check and correct the external device
PRO transmit message and restart data
communications.
 Set to ON at GX Configurator-SC.
PRO
 Set to ON at GX Developer.
 Check and correct the external device
PRO transmit message and restart data
communications.

1
MELSEC-Q
Protocol
Non
Bidire- Pre-
MC Proce-
ctional defined
dure
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