This is a technical manual for Siemens SIMATIC S7-300/400 series PLCs. It provides detailed information on the features, functions and usage of the PLCs.
This manual provides a comprehensive overview of the system software used in Siemens S7‑300 and S7‑400 CPUs. It details organization blocks (OB), system functions (SFC), system and standard function blocks (SFB) and IEC functions, together with diagnostic data and system status lists.
The document also includes usage instructions for STEP 7 V5.3 programming, online help integration, and support information for Siemens automation products worldwide. This manual is written in Chinese.
It copies a storage area.
It delays user program execution.
Use SFC0 SET_CLK to set the time‑of‑day (TOD).
SFC87 C_DIAG performs the diagnosis.