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Speed actual value / tachometer / encoder feedback

Siemens SIMOREG 6RA70 Speed Feedback and Tachometer Path

Separates speed-feedback instability into selected feedback source, analog tachometer polarity and voltage, encoder pulse evidence, wiring, shielding, mechanical coupling and CUD1 feedback input boundaries.

Circuit / feedback path8 min read

Scope of this technical record

Speed-feedback path for tachometer, encoder or armature-voltage feedback evidence before CUD1 input conclusions.

Safety boundary

Qualified personnel only.

6RA70 tachometer feedback path

1Feedback type
→
2Device
→
3Wiring
→
4Scaling
→
5Actual speed
→
6CUD1

The signal path must be credible before speed-loop work.

6RA70 tachometer feedback path

Siemens 6RA70 tachometer feedback path device terminals scaling actual speed CUD1
The path keeps feedback source and wiring ahead of CUD1 conclusions.

What the path separates

The path starts at selected feedback source and mechanical coupling, then moves through signal polarity, scaling, cable, shield, terminals and actual-speed behavior before CUD1 input evidence.

Field record checklist

  • Feedback type
  • Coupling
  • Signal at source
  • Signal at terminal
  • Polarity
  • Scaling
  • Actual speed

Technical basis and reference documents

This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.

FAQ for 6RA70 DC MASTER and SIMOREG CM fault diagnosticsSiemens Industry Support

OEM troubleshooting reference for 6RA70 fault values, tachometer checks, CUD1 / power-interface context and optimization-run faults.

SIMOREG DC-MASTER 6RA70 operating instructionsSiemens / SIMOREG documentation archive

Base operating and commissioning context for SIMOREG DC-MASTER converters, parameterization and speed-sensing setup.

Evidence intake

Turn this record into a qualified service request

A repair decision is much more reliable when the request includes the exact identity of the drive, the first fault evidence and the machine condition when the symptom appeared.

  • Complete drive type code / MLFB or nameplate model
  • Fault code, fault value and first event before reset
  • When the event appears: power-up, enable, ramp, run, decel or stop
  • Motor/cable connected or isolated during the symptom
  • Visible board, option-card, module and connector identifiers
  • Previous repair history, replacement parts and repeat-failure pattern
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