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Siemens SINUMERIK Controller
Spindle · Intermediate · 30-120 minutes
Siemens 840D 20065 - Channel master spindle not defined for geometry axes in JOG mode
Alarm 20065 occurs when attempting JOG mode traversal of a geometry axis with rotary feed, but the NCK cannot identify a master spindle to derive the required actual speed feedback. This typically stems from missing or incorrect master spindle assignment in the channel configuration or machine data, preventing synchronized rotary axis motion.
20065
Siemens 840D 20065 - Channel master spindle not defined for geometry axes in JOG mode
Channel master spindle not defined for geometry axes in JOG mode
Siemens SINUMERIK 840D alarm 20065: Channel master spindle not defined for geometry axes in JOG mode. This alarm indicates a program or channel-level error on the SINUMERIK control. The part program or machine function cannot be executed as commanded.
Root Cause Summary
Alarm 20065 occurs when attempting JOG mode traversal of a geometry axis with rotary feed, but the NCK cannot identify a master spindle to derive the required actual speed feedback. This typically stems from missing or incorrect master spindle assignment in the channel configuration or machine data, preventing synchronized rotary axis motion.
Safety
- Refer to Siemens documentation
- Ensure qualified technician performs repairs
Causes and Fixes
- 1
Access Siemens HMI Diagnostic menu: Service > Parameters > Machine Data (MD). Navigate to the affected channel and check MD20050 (Spindle number for this channel) and MD20051 (Master spindle assignment).
Ensure you have appropriate service credentials; unauthorized parameter access may trigger security alarms.
- 2
Verify the master spindle number is valid and matches an existing spindle definition in MD10000 (Number of spindles). Common assignment: MD20050=1 and MD20051=1 for standard single-spindle configurations.
- 3
If MD20050 or MD20051 is 0 or undefined, assign the correct spindle number corresponding to your configured spindle. Consult the machine builder's parameter documentation for proper channel-to-spindle mapping.
- 4
Save parameters (Store) and perform a warm restart (NCK reset via HMI or Ctrl+Shift+R). Retry JOG mode with rotary feed on the geometry axis.
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Always verify with your machine manual or a certified technician before performing service procedures.