Error Conditions

IEC standards table for error conditions:

Error conditions	Treatment (see Note)
Nested comments	2) error is reported during programming
Value of a variable exceeds the specified subrange	4) error is reported during execution
Missing configuration of an incomplete address specification ("*" notation)	Not applicable
Attempt by a program organization unit to modify a variable which has been declared `CONSTANT`	2) error is reported during programming
Improper use of directly represented or external variables in functions	Not applicable
A `VAR_IN_OUT` variable is not "properly mapped"	2) error is reported during programming
Type conversion errors	4) error is reported during execution
Numerical result exceeds range for data type	4) error is reported during execution
Division by zero	4) error is reported during execution
Mixed input data types to a selection function	2) error is reported during programming
Result exceeds range for data type	4) error is reported during execution
No value specified for an in-out variable	2) error is reported during programming
Zero or more than one initial steps in SFC network	3) error is reported during analyzing/loading/linking
User program attempts to modify step state or time	2) error is reported during programming
Side effects in evaluation of transition condition	3) error is reported during analyzing/loading/linking
Action control contention error	3) error is reported during analyzing/loading/linking
Simultaneously true, non-prioritized transitions in a selection divergence	Not applicable
Unsafe or unreachable SFC	3) error is reported during analyzing/loading/linking
Data type conflict in `VAR_ACCESS`	Not applicable
A task fails to be scheduled or to meet its execution deadline	4) error is reported during execution
Numerical result exceeds range for data type	4) error is reported during execution
Current result and operand not of same data type	2) error is reported during programming
Division by zero	4) error is reported during execution
Numerical result exceeds range for data type	4) error is reported during execution
Invalid data type for operation	4) error is reported during execution
Return from function without value assigned	Not applicable
Iteration fails to terminate	4) error is reported during execution
Same identifier used as connector label and element name	Not applicable
Uninitialized feedback variable	1) error is not reported

Note

Identifications for the treatment of error conditions according to IEC 61131-3, subclause 1.5.1, d):

1) error is not reported
2) error is reported during programming
3) error is reported during analyzing/loading/linking
4) error is reported during execution