PLC

Data types

When programming in TwinCAT, you can use different data types or instances of function blocks. You assign a data type to each identifier. The data type determines how much memory space is allocated and how these values are interpreted.

The following groups of data types are available:

 

Standard data types

TwinCAT supports all data types described in the IEC 61131-3 standard.

BOOL
 
 

Extensions of the IEC 61131-3 standard:

BIT
 
 

User-defined data types

 
Note
Note the recommendations for naming objects.

User-defined data types that you create as DUT object in the TwinCAT PLC project tree:

 
Additional information
BOOL
Integer Data Types
REAL / LREAL
STRING
WSTRING
Time Data Types
LTIME
BIT
ANY and ANY_<type>
Special data types XINT, UXINT, XWORD and PVOID
Pointer
REFERENCE
ARRAY
Subrange Types
Structure
Enumerations
Alias
UNION