What the Er.102 alarm means

The drive cannot communicate with the motor encoder; position feedback is lost and the axis is disabled. This is one of the faults our repair team handles on INOVANCE IRCB500 / IRCB501 + SV660 servo systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • Encoder cable broken inside the cable chain
  • Connector pins oxidized or backed out
  • Noise on the encoder line from poor shielding
  • Encoder or drive interface circuit failure
Field note: the first item on this list is what we find most often on real machines. Check it before you go deeper.

Step-by-step field fix

  1. Reseat the encoder connectors at both ends
  2. Continuity-test the cable through the full motion of the cable chain
  3. Check shield termination and separation from power cables
  4. Swap-test with a known-good cable
  5. Replace encoder (motor) or drive based on swap results
Safety first: never bypass safety circuits or force contactors closed. If the alarm involves E-stop chains, brakes or drive power, and you are not a trained robot technician, contact a professional — wrong moves here can cost you a robot or an injury.

Still stuck? Get an engineer on the phone — right now

Tell us the alarm code, the robot model and what was happening when the alarm came up. Our engineers run these diagnostics every day, and remote diagnosis by phone or video call is free.

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Hotline: +86-20-39029800 · WhatsApp: +86-188-1886-2860

Related Encoder & Position alarms

Er.740 — Encoder Signal Interference / Count Error Er.831 — Absolute Encoder Battery Low
Other brands: we also keep field-fix libraries for EFORT · JAKA · AUBO and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the INOVANCE Er.102 alarm mean?

The drive cannot communicate with the motor encoder; position feedback is lost and the axis is disabled. In field practice it belongs to the encoder & position family of faults.

QCan I clear a INOVANCE Er.102 alarm myself?

Sometimes. Work through the step-by-step checks on this page — the first listed cause is what we find most often in the field. If the alarm returns after two attempts, or the fault involves power, brakes or safety circuits, stop and call a qualified robot service engineer.

QHow fast can a Henghuan engineer help?

On-site response in the Pearl River Delta within 30 minutes to 3 hours, across mainland China in 1-3 business days, and worldwide within 2-5 business days. Remote diagnosis by phone/WhatsApp/video is available immediately.

Written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your INOVANCE documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by INOVANCE.