Siemens SIMATIC S7-300 Manual page 121

User program
In SIMATIC, a distinction is made between the operating system of the CPU and user
programs. The latter are created by the STEP 7 programming software in the available
programming languages (ladder logic and statement list) and are stored in code blocks. Data
is stored in data blocks.
Working memory
The working memory is a RAM in the CPU that the processor accesses when processing the
user program.
S7-300 CPU Data: CPU 315T-2 DP
Manual, 12/2005, A5E00427933-02
Glossary
Glossary-11