This guide introduces the SIMATIC S5‑155U programmable controller equipped with the CPU 948. It explains the controller’s architecture, typical mode of operation, and how user programs are structured, including STEP 5 language basics, function blocks, and data blocks.
The document also covers advanced topics such as program execution levels (cyclic, time‑controlled, interrupt‑driven), special integrated functions, memory management, and multiprocessor communication, with reference tables, examples, and an appendix of technical data.
| User memory (CPU 948‑1) | 640 Kbytes |
|---|---|
| User memory (CPU 948‑2) | 1 664 Kbytes |