8 TROUBLESHOOTING
MELSEC-Q
8 - 122 8 - 122
*1 : Characters in parentheses ( ) indicate the special register numbers where individual information is being
stored.
*12: This applies to the CPU module of function version B or later.
Error
Code
(SD0)
*1
Error Contents and Cause Corrective Action
Corresponding
CPU
4421
Total number of steps in all SFC
programs exceed the range.
Reduce total number of steps to below
the maximum.
4422
Step number designations overlap in
SFC program.
Read common information of the error
using the peripheral device, check
error step corresponding to its
numerical value (program error
location), and correct the problem.
4423
Step relays are insufficient in the SFC
program.
Read the common information of the
error using GX Developer, and check
and correct the error step
corresponding to that value (program
error location).
Q00J/Q00/
Q01
*12
4430
The SFC program cannot be
executed.
• The data of the block data setting is
illegal.
• The SFC data device of the block
data setting is beyond the device
setting range set in the PLC
parameter.
• Write the program to the CPU
module again using GX Developer.
• After correcting the setting of the
SFC data device, write it to the CPU
module.
• After correcting the device setting
range set in the PLC parameter,
write it to the CPU module.
4431
The SFC program cannot be
executed.
• The block parameter setting is
abnormal.
Write the program to the CPU module
again using GX Developer.
4432
The SFC program cannot be
executed.
• The structure of the SFC program is
illegal.
To Next Page
Loading...
