Omron SYSMAC CJ - REFERENCE MANUAL 01-2008 Reference Manual page 53

Instruction Execution Checks
Error type
No END Instruction
Task Error
Instruction Processing
Error*
Access Error*
Indirect DM/EM BCD
Error*
Differentiation Overflow
Error
UM Overflow Error
Illegal Instruction Error
14
All errors for which the Error Flag or Access Error Flag turns ON is treated as
a program error The following table lists program errors. The PLC Setup can
be set to stop program execution when one of these errors occurs.
Description
There is no END(001) instruction in the program.
There are three possible causes of a task error:
1) There is not an executable cyclic task.
2) There is not a program allocated to the task.
3) An interrupt was generated but the corresponding interrupt
task does not exist.
The CPU attempted to execute an instruction, but the data
provided in the instruction's operand was incorrect.
*If the PLC Setup has been set to treat instruction errors as
fatal errors (program errors), the Instruction Processing Error
Flag (A29508) will be turned ON and program execution will
stop.
There are five possible causes of an access error:
1) Reading/writing to the parameter area.
2) Writing to memory that is not installed.
3) Reading/writing to an EM bank that is EM file memory.
4) Writing to a read-only area.
5) The contents of a DM/EM word was not BCD although the
PLC is set for BCD indirect addressing.
*If the PLC Setup has been set to treat instruction errors as
fatal errors (program errors), the Illegal Access Error Flag
(A29510) will be turned ON and program execution will stop.
The contents of a DM/EM word was not BCD although the
PLC is set for BCD indirect addressing.
*If the PLC Setup has been set to treat instruction errors as
fatal errors (program errors), the Indirect DM/EM BCD Error
Flag (A29509) will be turned ON and program execution will
stop.
Differentiated instructions were repeatedly inserted and
deleted during online editing (over 31,072 times).
The last address in UM (user program memory) has been
exceeded.
The program contains an instruction that cannot be executed. Illegal Instruction Error
Section 1-2
Related flags
No END Error Flag
(A29511)
Task Error Flag (A29512)
Error (ER) Flag,
Instruction Processing
Error Flag (A29508)
Access Error (AER) Flag,
Illegal Access Error Flag
(A29510)
Access Error (AER) Flag,
Indirect DM/EM BCD Error
Flag (A29509)
Differentiation Overflow
Error Flag (A29513)
UM Overflow Error Flag
(A29515)
Flag (A29514)