What causes Siemens SINUMERIK alarm 27220?

Parameter or machine data configuration error. Hardware fault on the NC or drive component. Part program error or illegal command. Communication fault between NC and drive or I/O modules. Software or firmware error requiring system restart.

How do I fix Siemens SINUMERIK alarm 27220?

1. Note the complete alarm text including any axis, channel, or block number values. 2. Check for related alarms active simultaneously in the SINUMERIK alarm list. 3. Power cycle the machine to clear transient faults. 4. Review the SINUMERIK machine data for parameters related to the alarm. 5. Consult the Siemens SINUMERIK alarm manual for alarm 27220 detailed remedy.

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Siemens SINUMERIK Controller

Safety · Intermediate · 30-120 minutes

Alarm 27220

Siemens 840D 27220 - PROFIsafe: Number of NCK F modules <> Number of S7 F modules

Alarm 27220 indicates a mismatch between the number of F (safety) modules configured in the NCK via machine data $MN_PROFISAFE_IN_ADDRESS and $MN_PROFISAFE_OUT_ADDRESS versus the actual number of F modules present in the S7 PLC PROFIBUS configuration. This configuration discrepancy prevents proper PROFIsafe communication establishment between the NCK and safety-rated I/O modules.

Siemens SINUMERIKSafetyIntermediate30-120 minutes

27220

Siemens 840D 27220 - PROFIsafe: Number of NCK F modules <> Number of S7 F modules

PROFIsafe: Number of NCK F modules <> Number of S7 F modules

Root Cause Summary

Alarm 27220 indicates a mismatch between the number of F (safety) modules configured in the NCK via machine data $MN_PROFISAFE_IN_ADDRESS and $MN_PROFISAFE_OUT_ADDRESS versus the actual number of F modules present in the S7 PLC PROFIBUS configuration. This configuration discrepancy prevents proper PROFIsafe communication establishment between the NCK and safety-rated I/O modules.

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Causes and Fixes

1
Access NCK machine data via SINUMERIK Operate: Menu > Customize > Machine Data. Locate $MN_PROFISAFE_IN_ADDRESS (input F module count) and $MN_PROFISAFE_OUT_ADDRESS (output F module count). Document both values.
Requires HMI access level 3 (manufacturer) or higher.
2
In TIA Portal or STEP 7, open the PROFIBUS configuration (GSD files) under the S7-1200/1500 CPU node. Count the actual number of F modules (type ET 200 F, F-I/O modules, or equivalent PROFIsafe nodes) in the slave list.
Ensure PROFIBUS GSD files are updated to match installed hardware versions.
3
Correct the NCK machine data values to match the S7 PROFIBUS configuration count. Set $MN_PROFISAFE_IN_ADDRESS and $MN_PROFISAFE_OUT_ADDRESS to the actual number of F modules configured in the PLC. Transfer to NCK via Operate Menu > Machine Data > Transfer.
Save and backup machine data before modification. A warm restart may be required.
4
Perform a PROFIsafe safety validation cycle: Switch to automatic mode, trigger a controlled PROFIsafe handshake test, and verify alarm 27220 is cleared in the alarm history (Menu > Diagnostics > Alarms).
Do not operate the machine in manual modes until PROFIsafe initialization completes successfully.

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