Mitsubishi Electric MELSEC Q Series Programming Manual page 221

6 TROUBLESHOOTING
Error Detail
code code Error contents
(SD32) (SD33)
Data
transfer
error code
4026H Sequence
programs for safety
21
observation
transfer error
4029H
Data Sequence
transfer programs for safety
22
request observation
code transfer timeout
Sequence
programs for safety

23
observation
comparison error
Safety observation

24 processing stop
(PLC CPU)
Safety observation

25 processing stop
(Motion CPU)
Error
Safety signal output
device No.
26 FB comparison
(HEX)
error
(Note-3)
Parameter
Safety observation
27 No. parameter setting
(Note-4)
error
Safety observation

28 parameter compare
error
Table 6.1 Safety observation error list (Continued)
Error cause
A data transfer request from Motion CPU to
PLC CPU was not correctly handled.
An access from the Motion CPU is
unavailable because a password is
registered for the sequence programs for
safety observation of the PLC CPU
(SSU_CMP/SLS_CMP/SNT_CMP).
The user ladder area doesn't have enough
available area to write the sequence
programs for safety observation.
A data transfer request from Motion CPU to
PLC CPU was aborted.
This error may occur when access to the
sequence program file using other devices
such as GX Works2 and a GOT is
attempted.
A mismatch between sequence programs
for safety observation written in PLC CPU
and that stored in Motion CPU was
detected.
It is assumed that the PLC CPU or Motion
CPU may be damaged.
The safety observation processing of the
PLC CPU is not working or delayed. The
following reasons may be responsible:
• "SSU_CMP" or "SLS_CMP" (when the
speed monitoring function is used) is not
registered to [PLC parameter] on
[Program setting] page.
• The scan time of the PLC CPU exceeds
100ms (when the speed monitoring
function is not used) or 25ms (when the
speed monitoring function is used).
The safety observation processing of the
Motion CPU is not working or delayed.
A mismatch between output signals from
safety signal unit and their feedback
signals was detected.
The following cause is assumed:
• 24VDC power is not supplied to the safety
signal module.
• The actual I/O number assignment of
parameters to the safety signal module
station is different from the setting.
An error of the safety observation
parameter was detected.
The parameters relating to safety
observation are not correctly transmitted
from Motion CPU to PLC CPU.
Corrective action
Explain the error symptom and get advice
from our sales representative.
Do not change the password settings of the
sequence programs for safety observation
(SSU_CMP/SLS_CMP/SNT_CMP).
Check the available area size of the user
sequence program area.
If the size is not enough, reduce the number
of steps in the user sequence program or
delete the unnecessary data on the program
memory.
Turn ON the controller again after breaking
the access of other devices.
Explain the error symptom and get advice
from our sales representative.
Check the PLC parameter setting.
When the scan time is long, shorten it such as
by reducing the number of steps of the user
sequence program.
Explain the error symptom and get advice
from our sales representative.
Supply 24VDC to safety signal module.
After confirming that safety signals are
correctly output, turn ON the controller again.
Check if the I/O No. set in the parameter and
the station No. of the safety signal module
properly correspond.
If this remedy still can't solve the error, the
safety signal unit may be damaged.
Reconsider the safety observation parameter
setting corresponding to the small
classification code, and write it to the Motion
CPU.
Check if the multiple CPU area device for the
safety observation function has not been
changed in a user program.
If the error cannot be resolved, explain the
error symptom and get advice from our sales
representative.
6 - 2
Relevant CPU
PLC Motion Reset
CPU CPU





