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Siemens SINUMERIK Controller
Servo/Axis · Intermediate · 30-120 minutes
Siemens 300739 - Axis drive measuring system already used as motor measuring
This alarm occurs when the NC attempts to assign a direct measuring system to an output already used by another motor measuring system. This is a configuration conflict that must be resolved by reassigning measuring systems to unique outputs.
300739
Siemens 300739 - Axis drive measuring system already used as motor measuring
Axis drive measuring system already used as motor measuring
The NC has assigned the direct measuring system to a measuring system output which is already used by another motor measuring system. This error can only occur with the 810D! Control reaction: NC not ready. The NC switches to follow-up mode. Channel not ready. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm.
Root Cause Summary
This alarm occurs when the NC attempts to assign a direct measuring system to an output already used by another motor measuring system. This is a configuration conflict that must be resolved by reassigning measuring systems to unique outputs.
Safety
- Drive/power/encoder circuit: hazardous voltages may remain in the DC link after power-off. Lock out / tag out, wait for discharge per the drive documentation, and use qualified personnel only.
Causes and Fixes
- 1
SAFETY: Power down and lockout
Follow LOTO procedures before accessing machine data. Ensure all axes are at safe positions.
- 2
Identify conflict
Check machine data MD36300 (direct measuring system assignment) and MD34200 (motor encoder assignment) for the affected axis to identify duplicate output assignments.
- 3
Reassign measuring system
Modify machine data to assign measuring systems to unique, available outputs. Document original values before changes.
- 4
Validate and restart
Perform controlled restart following manufacturer procedures. Test axis movement at reduced speeds initially.
Call a technician if:
- ·Always - machine data changes require qualified technician
- ·If unsure about measuring system hardware configuration
- ·Before making any machine data modifications
Prevention
- Validate measuring system assignments before running
- Use simulation to detect configuration conflicts
Common Mistakes
- Overlooking duplicate output assignments
- Editing unrelated machine data parameters
Seeing Multiple Alarms?
Seeing another alarm with this one? Enter the code.
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