Technical data

Creating Blocks and Libraries
9.4 Working with Libraries
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 237
9.4.1 Hierarchical Structure of Libraries
Libraries are structured in a hierarchical manner, just like projects:
• Libraries can contain S7/M7 programs.
• An S7 program can contain one "Blocks" folder (user program), one "Source Files" folder, one
"Charts" folder, and one "Symbols" object (symbol table).
• An M7 program can contain charts and C programs for programmable M7 modules as well as a
"Symbols" object (symbol table) and a "Blocks" folder for data blocks and variable tables.
• The "Blocks" folder contains the blocks that can be downloaded to the S7 CPU. The variable
tables (VAT) and user-defined data types in the folder are not downloaded to the CPU.
• The "Source Files" folder contains the source files for the programs created in the various
programming languages.
• The "Charts" folder contains the CFC charts (only if the S7 CFC optional software is installed).
When you insert a new S7/M7 program, a "Blocks" folder, "Source Files" folder (S7 only), and a
"Symbols" object are inserted automatically in it.
9.4.2 Overview of the Standard Libraries
The STEP 7 standard software package contains the following standard libraries
• System Function Blocks: System Function Blocks (SFBs) and System Functions (SFCs)
• S5-S7 Converting Blocks: Blocks for converting STEP 5 programs
• IEC Function Blocks: Blocks for IEC functions, e.g. for processing time and date information,
comparison operations, string processing and selecting the min./max. values
• Organization Blocks: Default organization blocks (OB)s
• PID Control Blocks: Function Blocks (FBs) for PID control
• Communication Blocks: Functions (FCs) and function blocks for SIMATICNET CPs.
• TI-S7 Converting Blocks: Standard functions for general use
• Miscellaneous Blocks: Blocks for time stamping and for TOD synchronization
When you install optional software packages, other libraries may be added.
Deleting and Installing the Supplied Libraries
You can delete the supplied libraries in SIMATIC Manager and then reinstall them. Run STPE 7
Setup to install the libraries.
Note
When you install STEP 7, the supplied libraries are always copied. If you edit these libraries, the
modified libraries will be overwritten with the originals when STEP 7 is installed again.
For this reason, you should copy the supplied libraries before making any changes and then only edit
the copies.