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Siemens SINUMERIK Controller
Safety · Intermediate · 30-120 minutes
Siemens 840D 27206 - PROFIsafe: MD number of F user data ( bits)
Alarm 27206 fires when PROFIsafe F user data allocation in machine data exceeds the maximum bit capacity defined by the F module configuration. This occurs when PROFISAFE_IN_ADDRESS or PROFISAFE_OUT_ADDRESS parameters reference sub-slot addresses that push the total F user data payload beyond the module's declared limit (%3 bits).
27206
Siemens 840D 27206 - PROFIsafe: MD number of F user data ( bits)
PROFIsafe: MD number of F user data ( bits)
Siemens SINUMERIK alarm 27206: PROFIsafe: MD [] maximum number of F user data ( bits). This alarm indicates a fault or error condition on the SINUMERIK 840D control. Refer to the Siemens SINUMERIK alarm documentation for the complete description and remedy.
Root Cause Summary
Alarm 27206 fires when PROFIsafe F user data allocation in machine data exceeds the maximum bit capacity defined by the F module configuration. This occurs when PROFISAFE_IN_ADDRESS or PROFISAFE_OUT_ADDRESS parameters reference sub-slot addresses that push the total F user data payload beyond the module's declared limit (%3 bits).
Safety
- Refer to Siemens documentation
- Ensure qualified technician performs repairs
Causes and Fixes
- 1
Access Siemens automation HW Config or STEP 7 and verify the F module (safety module) declaration. Document the maximum F user data bits shown in the module properties.
- 2
Navigate to NCK → Machine Data → PROFISAFE group. Retrieve current MD 27200 (PROFISAFE_IN_ADDRESS) and MD 27201 (PROFISAFE_OUT_ADDRESS) values. Calculate: (sub-slot offset + F data size in bits) to confirm it does not exceed the module limit.
Document exact byte/bit offsets; F module addressing is byte-aligned but bit-precise for safety payload.
- 3
Reduce the sub-slot address offset or reduce the number of F user data words allocated. Ensure the combined footprint stays within the module's maximum declared bits.
- 4
Verify F module hardware revision supports the required F user data size. If undersized, upgrade to a module variant with larger F user data capacity or split safety functions across multiple F modules.
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