Technical data

Programming with STEP 7
Manual, 05/2010, A5E02789666-01 279
13 Creating STL Source Files
13.1 Basic Information on Programming in STL Source Files
You can enter your program or parts of it as an STL source file and then compile it into blocks in
one step. The source file can contain the code for a number of blocks, which are then compiled as
blocks in one compilation run.
Creating programs using a source file has the following advantages:
• You can create and edit the source file with any ASCII editor, then import it and compile it into
blocks using this application. The compilation process creates the individual blocks and stores
them in the S7 user program.
• You can program a number of blocks in one source file.
• You can save a source file even if it contains syntax errors. This is not possible if you create
logic blocks using an incremental syntax check. However, the syntax errors are only reported
once you compile the source file.
The source file is created in the syntax of the programming language representation Statement List
(STL). The source file is given its structure of blocks, variable declaration, and networks using
keywords.
When you create blocks in STL source files you should note the following:
• Guidelines for Programming STL Source Files
• Syntax and Formats for Blocks in STL Source Files
• Structure of Blocks in STL Source Files