Mitsubishi MELSEC-Q/L Programming Manual page 417

Operation Error
(1) In any of the following cases, an operation error occurs, the error flag (SM0) turns ON, and an error code is stored into
SD0.
Error
code
The IX and IXEND instructions are not used as a pair.
4231 After the IX instruction was executed, the END, FEND, GOEND, or
STOP instruction was executed prior to the IXEND instruction.
Program Example
(1) The following program executes the same ladder 10 times, while changing device numbers.
[Ladder Mode]
[Operation]
Modification value
D100 Modification value of T
D101 Modification value of C
D102 Modification value of X
D103 Modification value of Y
D104 Modification value of M
D105 Modification value of L
D106 Modification value of B
D107 Modification value of V
D108 Modification value of D
Error details
Sets modification
value
Ladder which
executes index
modification
Changes
modification
value
1st time 2nd time 3rd time
B0
B1 B2
X10
X11
X12
Y30 Y31
Y32
M0 M1
M2
D0 D1
D2
D10
D11 D12
T3
T4
T5
C4
C5
C6
D40
D41
D42
Q00J/
Q00/ QnH QnPH QnPRH
Q01
[List Mode]
Step Instruction
10th time
B9
X19
Y39
M9
D9
D19
T12
C13
D49
IX, IXEND
1
2
QnU LCPU
3
4
4
Device
6
7
8
415