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Siemens SINUMERIK Controller
Servo/Axis · Intermediate · 30-120 minutes
Siemens 75212 - RCTR: incorrect TRAFO_TYPE_ : use 4100
Alarm 75212 occurs when the TRAFO_TYPE machine data parameter for a specific axis channel contains an invalid transformer type value instead of the required 4100 (standard current transformer configuration). This prevents the NCK from correctly initializing the servo drive transformer interface and axis control loop.
75212
Siemens 75212 - RCTR: incorrect TRAFO_TYPE_ : use 4100
RCTR: incorrect TRAFO_TYPE_ : use 4100
The transformer type entered in MD TRAFO_TYPE_x is incorrect Control reaction: Interpreter stop Alarm display.
Root Cause Summary
Alarm 75212 occurs when the TRAFO_TYPE machine data parameter for a specific axis channel contains an invalid transformer type value instead of the required 4100 (standard current transformer configuration). This prevents the NCK from correctly initializing the servo drive transformer interface and axis control loop.
Safety
- Only qualified personnel should diagnose and clear control alarms; follow the machine builder's safety procedures and lockout/tagout where hardware work is required.
Causes and Fixes
- 1
Navigate to Diagnostics > Parameters > MD > TRAFO_TYPE_[channel] in the 840D operator panel. Verify the current value displayed for the affected channel number referenced in the alarm.
- 2
If the value is not 4100, edit the parameter and set it to exactly 4100 (standard transformer for current-controlled servo loop).
Do not use legacy values like 3100 or 3200 which may have been valid in older SINUMERIK versions.
- 3
Confirm the parameter change and perform a warm restart (RESET) or cold restart (power cycle) to allow the NCK to reload and validate the MD.
- 4
Verify the alarm no longer appears and that axis servo commissioning completes without 75212 errors.
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