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Siemens SINUMERIK Controller
Safety · Intermediate · 30-120 minutes
Siemens 840D 101633 - Write access only in start-up state Safety (p10=95).
Alarm 101633 is a safety-class alarm that fires when write access to safety-critical parameters or machine data is attempted outside the machine's start-up state. The NCK/PLC system restricts modifications to safety parameters (particularly those controlled by MD parameter p10=95) to prevent unauthorized or accidental changes to safety functions during normal operation.
101633
Siemens 840D 101633 - Write access only in start-up state Safety (p10=95).
Write access only in start-up state Safety (p10=95).
Siemens SINUMERIK 840D alarm 101633: Write access only in start-up state Safety (p10=95). This alarm indicates a fault condition on the specified axis or channel that requires investigation before machining can resume.
Root Cause Summary
Alarm 101633 is a safety-class alarm that fires when write access to safety-critical parameters or machine data is attempted outside the machine's start-up state. The NCK/PLC system restricts modifications to safety parameters (particularly those controlled by MD parameter p10=95) to prevent unauthorized or accidental changes to safety functions during normal operation.
Safety
- Refer to Siemens documentation
- Ensure qualified technician performs repairs
Causes and Fixes
- 1
Power-cycle the machine completely (Emergency Stop > Power Off > 30-second wait > Power On) to force the system into start-up state (p10=95).
Ensure all personnel are clear of the machine envelope before power cycling.
- 2
Access Diagnostics > System > Machine Data (MD) and verify MD parameter p10 displays value 95 (start-up state). If p10≠95, the system did not initialize correctly.
- 3
Attempt the safety parameter write operation only during this confirmed start-up state window before transitioning to RUN mode.
- 4
If the alarm persists after power-cycle, check Diagnostics > Alarms > Archive for related parameter validation errors (alarms 101634, 101635) indicating corrupted safety data.
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