Features:
- The CPU executes the S7-400 control program and updates a configurable process image.
- Code and data divide the 144 KB work-memory area into two equal sections.
- One MPI/DP interface and one isolated DP interface separate programming and field-network roles.
Input data enters through rack and PROFIBUS paths before it reaches the process image.
The CPU executes the user program against that image and its internal memory areas.
Updated output data and diagnostic information return through the rack and configured network interfaces.
The Siemens 6ES7412-2XG00-0AB0 SIMATIC S7-400 CPU 412-2 may still be available for purchase and support from Apter Power beyond End-Of-Life (EOL) by the manufacturer (OEM).
Siemens 6ES7412-2XG00-0AB0 SIMATIC S7-400 CPU 412-2 Manuals,Datasheets,Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Separating program execution from project storage
- Work memory: 144 KB is divided into 72 KB for code and 72 KB for data.
- Integrated load RAM: The CPU includes 256 KB for project storage.
- Memory card: Flash or RAM cards can extend load memory to 64 MB.
- Execution path: The CPU loads executable blocks into work memory before program processing.
Assigning different network roles to the two integrated interfaces
- First interface: MPI and PROFIBUS DP share one configurable connection.
- Second interface: An isolated connection serves PROFIBUS DP.
- Transfer rate: PROFIBUS communication reaches 12 Mbit/s.
- Slave limits: The first interface supports up to 32 slaves and the second up to 64.
Moving field data through the controller scan
- Input area: The CPU address space provides 4 KB for inputs.
- Output area: A separate 4 KB address space serves outputs.
- Default image: The standard process image begins at 128 bytes.
- Adjustment: The process image can be extended to 4 KB for the configured program.
Relating instruction time to controller event records
- Boolean processing: Bit instructions execute in 0.2 µs.
- Numeric processing: Fixed-point instructions take 0.2 µs and floating-point instructions 0.6 µs.
- Diagnostic history: The buffer retains 400 entries.
- Engineering path: STEP 7 assigns hardware, addresses, networks and program blocks to the CPU.