Subrange Types¶
A subrange type is a data type whose value range is a subset of a base type.
Syntax for the declaration:
<name> : <int type> (<lower limit>..<upper limit>);
<name> |
valid IEC identifier |
<int type> |
data type of the subrange (SINT, USINT, INT, UINT, DINT, UDINT, BYTE, WORD, DWORD, LINT, ULINT, LWORD). |
<lower limit> |
Lower limit of the range: constants that have to be compatible with the basic data type. The lower limit is also included in this range. |
<upper limit> |
Upper limit of the range: constants that have to be compatible with the base data type. The upper limit is also included in this range. |
Examples:
VAR
i : INT (-4095..4095);
ui : UINT (0..10000);
END_VAR
If you assign a value to a subrange type in the declaration or implementation section that is not within this range (example: i:=5000), then CODESYS issues an error message.
Note
Please note: In runtime mode, it is possible to monitor the range limits of a subrange type by using the implicit monitoring functions CheckRangeSigned and CheckRangeUnsigned.
See also