Technical data

Creating STL Source Files
13.3 Structure of Blocks in STL Source Files
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 287
13.3.2 Structure of Data Blocks in STL Source Files
A data block consists of the following areas that are introduced by their respective keywords:
• Block start, identified by keyword and block number or block name, for example,
DATA_BLOCK DB26
• Reference to an associated UDT or function block (optional)
• Optional block title introduced by the keyword TITLE = (entries longer than 64 characters are
cut off)
• Optional block comment, beginning with a double slash //
• Block properties (optional)
• Variable declaration section (optional)
• Assignment section with default values, beginning with BEGIN (optional)
• Block end, identified by END_DATA_BLOCK
There are three types of data block:
• Data blocks, user-defined
• Data blocks with an associated user-defined data type (UDT)
• Data blocks with an associated function block (known as "instance" data blocks)
13.3.3 Structure of User-Defined Data Types in STL Source Files
A user-defined data type consists of the following areas that are introduced by their respective
keywords:
• Block start, identified by keyword TYPE and number or name, for example, TYPE UDT20
• Structured data type
• Block end, identified by END_TYPE
When you enter a user-defined data type, you must ensure that user-defined data types precede
the blocks in which they are used.