Emergency: same day
For a line-down motor, where the fault and parts allow. WhatsApp us before you send it so the bench is kept free.
Incremental · Sine/cosine commutation encoder
Sine/cosine commutation encoder repair (ERN 1387, RON 3350)
Sine/cosine commutation encoder is a Incremental with sine/cosine commutation encoder with incremental plus sinusoidal C and D channels. We test it, repair or replace it and align it to the rotor. Found on: Siemens servo motors using ERN 1387 and RON 3350 type encoders. Star Automations is an independent multi-brand repair company and is not an OEM service centre.
- 25+years of servo repair, since 2000
- 3,000+customers across India
- 100+servo brands covered by our universal servo motor test equipment
- 5sites: Puducherry, Chennai, Bengaluru, Hyderabad, Delhi
- Same dayemergency repair option*
*Where the fault and parts allow. Every repaired unit returns with a printed test report.
Repair turnaround you can plan around
Send a photo of the nameplate first. We confirm whether the motor is repairable, and the quote, the same working day.
Urgent: 3 working days
Repair, encoder alignment and test, counted from the day the motor reaches the bench and the quote is approved.
Standard: 7 working days
Full repair, encoder alignment, run test under load and a printed test report.
- Free repairability check from a nameplate photo
- Printed test report with every motor
- Written warranty, terms stated on every quotation
- Pickup can be arranged; parts that must be imported are quoted with their own timeline
01Facts
Sine/cosine commutation encoder at a glance
| Device | Sine/cosine commutation encoder |
|---|---|
| Brand family | Incremental |
| Type and format | Incremental with sine/cosine commutation |
| Counts | incremental plus sinusoidal C and D channels |
| Found on | Siemens servo motors using ERN 1387 and RON 3350 type encoders |
| Connector | Per motor model |
| Pole setting for alignment | Set at alignment |
The C and D channel amplitudes are converted to a mechanical angle that should change smoothly from 0 to 359 degrees in one revolution, much like verifying a resolver.
02Faults
How Sine/cosine commutation encoder encoders usually fail
- Missing or weak A, B or Z channel
- Signal level outside range
- Dirty or damaged disc
- Commutation lines that no longer match the rotor
- Sine or cosine amplitude out of range
- Angle that moves through 360 degrees with only a slight rotation
03Process
How the repair is done
Receive and identify
We read the nameplate and encoder label and confirm the exact type.
Test
Count per turn, data status, alarm flags and, where fitted, incremental lines are checked on the bench.
Repair or replace
Board, connector or sensor faults are repaired; a matched encoder is fitted where repair is not sensible.
Align
Commutation is set to the rotor and checked at every pole pair using the electrical angle.
Verify and report
The motor is run on the bench and the readings are recorded in the report.
See encoder alignment, memory programming and replacement.
04Related
Other Incremental encoders we repair
05FAQ
Questions
Can you repair a Sine/cosine commutation encoder encoder?
Yes. We test the position count and status, repair or replace the encoder, align it to the rotor and run the motor. We repair Incremental units; Star Automations is an independent multi-brand repair company and is not an OEM service centre.
How is the angle checked?
Each quarter turn should change it by 90 degrees.
Which encoders use this?
ERN 1387 and RON 3350 types on Siemens motors.
What should I send for a Sine/cosine commutation encoder enquiry?
A clear photo of the motor nameplate and, if the cover is off, the encoder label. You can send the motor or only the encoder.
06Enquiry
Send the nameplate or encoder label
A clear photo of the motor nameplate and, if the cover is off, the encoder label is enough to start. We reply with whether it can be repaired and a quote.
Message received
Our team replies by email or WhatsApp, usually the same working day. For a line-down motor, WhatsApp +91 97866 22233.
→How it works
From nameplate photo to a tested motor in 7 steps
One route for servo motors, encoders and drives. You see the price before any work starts, and the report before the unit leaves our bench.
- 1 · Nameplate photoSend it on WhatsApp or the form
- 2 · Repairable? QuoteUsually the same working day
- 3 · Courier or pickupThe unit reaches our bench
- 4 · Bench diagnosisInsulation, windings, brake, encoder
- 5 · RepairFailed parts, bearings, seals, brake
- 6 · Align and run-testEncoder aligned; no-load and load run
- 7 · Report and dispatchPrinted test report with the unit
- Line down?Servo Swap ships a tested unit first. How Servo Swap works
EmergencySame day*
Urgent3 working days
Standard7 working days
*Where the fault and parts allow. Turnaround counts from when the unit reaches our bench and the quote is approved.