What causes Siemens SINUMERIK alarm 6431?

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 6431?

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 6431 detailed remedy.

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Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 30-120 minutes

Alarm 6431

Siemens 840D 6431 - Channel block Function not allowed. Tool

Alarm 6431 fires when G-code issues tool management commands (GETT, SETPIECE, GETSELT, NEWT, DELT) while the ToolMan (Tool Management) module is deactivated in the NCK. This is a software configuration issue where the CNC program attempts operations that require an inactive licensed feature.

Siemens SINUMERIKServo/AxisIntermediate30-120 minutes

6431

Siemens 840D 6431 - Channel block Function not allowed. Tool

Channel block Function not allowed. Tool

Root Cause Summary

Alarm 6431 fires when G-code issues tool management commands (GETT, SETPIECE, GETSELT, NEWT, DELT) while the ToolMan (Tool Management) module is deactivated in the NCK. This is a software configuration issue where the CNC program attempts operations that require an inactive licensed feature.

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Causes and Fixes

1
Access Siemens HMI or SINUMERIK Operate interface and navigate to Diagnostics > Machine Data. Search for MD10100 (ToolMan activation flag).
2
Verify MD10100 = 1 (enabled). If MD10100 = 0, ToolMan is deactivated. Change to 1 and restart the NCK via NC Reset or power cycle.
Changing MD10100 requires write access and may require service/commissioning authorization level.
3
Check Siemens license key status in HMI > Diagnostics > License Information. Confirm ToolMan license is installed and not expired.
4
If license is missing or expired, contact Siemens service to install valid ToolMan feature license. Reload license and restart NCK.

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