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.
Heidenhain · EnDat, incremental, Indramat digital
Heidenhain servo encoder repair: ECN, EQN, ECI, EQI, ERN and ROD
Heidenhain encoders sit on Siemens, Bosch Rexroth, B&R, Kollmorgen, Baldor, Stober, AMK and many other servo motors. We test EnDat, SSI and incremental 1 Vpp types, repair or replace them, set the commutation and, on motors that keep data in the encoder, write it back.
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
01Models
Encoder models we test, repair and replace
| Encoder | Interface | Resolution | Typical motors |
|---|---|---|---|
| ECN 1313-512 | EnDat, single-turn, optical | 8,192 positions per turn, 512 sine periods | Bosch, B&R |
| ECN 1313-2048 | EnDat, single-turn, optical | 8,192 positions, 2,048 sine periods | Siemens, Baldor, Bosch, B&R, Rexroth MSK |
| EQN 1325-2048 | EnDat, multi-turn, optical | 8,192 per turn, 4,096 turns | Siemens, Baldor, B&R, Rexroth MSK |
| EQN 1325 SSI | SSI, multi-turn | 8,192 per turn | Stromag, Ultract |
| ECI 1317-32 | EnDat, single-turn, inductive | 131,072 per turn | B&R 8LS, 8MS |
| EQI 1325-32 | EnDat, multi-turn, inductive | 8,192 per turn | Siemens |
| EQI 1327-32, EQI 1329-32 | EnDat, multi-turn, inductive | 32,768 and 131,072 per turn | B&R |
| ECI 1118, EQI 1128, EQI 1130, ECI 1319, EQI 1331 | EnDat, inductive | Varies by model | Compact servo motors |
| ECN 1123, EQN 1335, EQN 1337, ECN 125 | EnDat | Up to 33,554,432 per turn (ECN 125) | High-resolution axes |
| ERN 1387, ERN 1381 | Incremental 1 Vpp with C and D commutation tracks | 2,048 lines, 8,192 counts | Siemens 1FT6 and 1FK6, Lust and Stromag FIP/FHP |
| ERN 1326 | Incremental with commutation | Varies | Fadal and Baldor |
| RON 350, ERN 3350 | Incremental | 8,192 counts | Siemens |
| ROD 320, ROD 426, ROD 1424, ROD 1430 | Incremental | Varies | Siemens 1FT5, Indramat |
| RCN 220, RCN 223 | Absolute angle encoder, Fanuc serial protocol | High resolution | Rotary tables |
| ECN 212, EQN 224, ECN 413, EQN 425 (Indramat DSF/HSF) | Indramat digital | 1,024 or 2,048 | Indramat MDD and MHD |
Check the label: some ECN 1313 and EQN 1325 units are SSI, not EnDat, and need a different setup.
02Faults
How these encoders usually fail
- Contamination on the glass disc from oil or coolant that entered past a shaft seal
- Failed LED or photo-sensor, shown as weak or missing sine signals
- EnDat communication errors from damaged cables, connectors or line drivers
- Multi-turn gear stage damage on EQN and EQI units after a shaft impact
- Corrupted memory, so the drive no longer recognises the motor
- Commutation offset lost after a bearing change or a careless encoder removal
03Identify
Reading the label
EC means single-turn and EQ means multi-turn. A third letter N, as in EQN, means an optical disc; I, as in EQI, means inductive. The number after the dash, such as -2048 or -32, gives the sine periods or the resolution class. ERN and ROD are incremental. Indramat-branded versions carry a DSF or HSF part number, with SN for single-turn and MN for multi-turn.
04Motors
Motors fitted with these encoders
Siemens 1FT6, 1FK6, 1FK7 and 1FT7, Bosch Rexroth MSK and SF, Indramat MDD and MHD, B&R 8LS and 8MS, Kollmorgen and Danaher, Baldor, Stober ED, EK and EZ, AMK DT, Control Techniques Unimotor, Lust and Stromag, Ultract, Fadal.
05Service
What we do
Test and repair
Every check on the feedback test list, before and after repair.
Alignment
Commutation set to the rotor at every pole pair.
OpenMemory programming
Motor data written to a replacement encoder.
OpenReplacement
Matched encoder fitted, aligned and run tested.
Open06FAQ
Questions
Can an EnDat encoder be replaced without the motor maker?
Yes. We fit the same EnDat type, set the commutation offset and, where the motor keeps data in the encoder, write the motor data back before the run test.
Why does my Siemens motor show an encoder fault after a bearing change?
The encoder was probably removed and refitted without resetting its position to the rotor, or the disc was disturbed. The offset must be measured and set again.
Do you handle Heidenhain incremental encoders on older Siemens 1FT5 motors?
Yes, including ROD 320 and ROD 426 types and the Hall and tach feedback used on 1FT5 motors.
Free downloads for your maintenance file
Printable one-page sheets from our bench. More on the resources page.
Servo motor encoder quick reference
Encoder families, interfaces, counts per revolution and the motors they sit on: Fanuc pulsecoders (alpha A64, A1000), Mitsubishi OBA/OSA, Yaskawa UTOPH, Tamagawa, Heidenhain ECN/EQN/ERN and SICK SKS/SRS/SRM.
PDF · 2 pages · 8 KB · free, no sign-up
Download PDFServo encoder alarm quick sheet
Common encoder and feedback alarms on Fanuc, Yaskawa, Mitsubishi and Siemens drives, what each usually points to, and what to check on the cable and connector first.
PDF · 1 page · 4 KB · free, no sign-up
Download PDF07Enquiry
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.