Simatic S7dos Repack -

S7-DOS also handles – if an FB calls a missing FC, S7-DOS can load it from load memory on demand (though this increases cycle time). 5. Execution Model – The S7-DOS Cycle Simplified flow per CPU scan:

| Memory Area | Purpose | S7-DOS Mechanism | |-------------|---------|------------------| | Load memory (RAM/Flash) | User program code, blocks | File‑like block storage | | Work memory (RAM) | Runtime copies of code+data | iRMX segments | | System memory | OBs, SDBs, link data | Kernel dynamic allocation | | Retentive memory | Remanent data markers, counters | Battery‑backed, checksummed | simatic s7dos

| Protocol | Task | Priority | |----------|------|----------| | MPI | S7‑DOS task (low) | Cyclic | | PROFIBUS DP master | Background interrupt | High | | PROFINET (later) | Ethernet task | Mixed | S7-DOS also handles – if an FB calls