Program Execution Check - Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual

Checking Programs
Note
Multi-word Operands
1-3-3

Program Execution Check

Type of error
1. Instruction Processing Error
2. Access Error
3. Illegal Instruction Error
4. UM (User Memory) Overflow
Error
Instruction
Processing Errors
Area
Output duplication Duplicate output check
(See note.) • By bit
• By word
• Timer/counter instructions
• Long words (2-word and 4-word)
• Multiple allocated words
• Start/end ranges
• FAL numbers
• Instructions with multiple output operands
Tasks Check for tasks set for starting at beginning of operation
Task program allocation
Output duplication is not checked between tasks, only within individual tasks.
Memory area boundaries are checked for multi-word operands for the pro-
gram check as shown in the following table.
Check items The following functionality is provided by the CX-Programmer for
multi-word operands that exceed a memory area boundary.
• The program cannot be transferred to the CPU Unit.
• The program also cannot be read from the CPU Unit.
• Compiling errors are generated for the program check.
• Warnings will appear on-screen during offline programming.
• Warnings will appear on-screen during online editing in PRO-
GRAM or MONITOR mode.
Operand and instruction location checks are performed on instructions during
input and during program checks from the CX-Programmer. These are not,
however, final checks.
The following checks are performed during instruction execution.
Flag that turns ON for error
ER Flag
Note The Instruction Processing
Error Flag (A295.08) will
also turn ON if Stop Opera-
tion is specified when an
error occurs.
AER Flag
Note The Access Error Flag
(A295.10) will turn ON if
Stop Operation is specified
when an error occurs.
Illegal Instruction Error Flag
(A295.14)
UM Overflow Error Flag (A295.15) Fatal (program error)
An instruction processing error will occur if incorrect data was provided when
executing an instruction or an attempt was made to execute an instruction out-
side of a task. Here, data required at the beginning of instruction processing
was checked and as a result, the instruction was not executed, the ER Flag
(Error Flag) will be turned ON and the EQ and N Flags may be retained or
turned OFF depending upon the instruction.
Check
Stop/Continue operation
A setting in the PLC Setup can be used to spec-
ify whether to stop or continue operation for
instruction processing errors. The default is to
continue operation.
A program error will be generated and operation
will stop only if Stop Operation is specified.
A setting in the PLC Setup can be used to spec-
ify whether to stop or continue operation for
instruction processing errors. The default is to
continue operation.
A program error will be generated and operation
will stop only if Stop Operation is specified.
Fatal (program error)
Section 1-3
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