What the 1020 alarm means

One or more confirmation-required messages are still active, and KSS blocks the requested action until they are acknowledged. This is one of the faults our repair team handles on KUKA KRC2 / KRC4 / KRC5 (KSS) systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • An earlier fault was never cleared with the acknowledgment key
  • Message stack overflow hiding the original fault
  • An intermittent fault re-triggering the same message
  • Faulty acknowledgment key on the SmartPad
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. Open the message window and read the OLDEST active message — that is the root fault
  2. Clear the root cause first, then acknowledge
  3. If the stack is full, acknowledge and clear messages one by one from the log
  4. Check Diagnosis → Message Log for the recurring fault pattern
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.

Get a Free Remote Diagnosis See Repair Services

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

Related System & Program alarms

1004 — File System Error 1015 — No Program Selected 1030 — External Start Missing ($EXT_START) 15102 — SmartPad (Teach Pendant) Fault
Other brands: we also keep field-fix libraries for ABB · Yaskawa · Universal Robots and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the KUKA 1020 alarm mean?

One or more confirmation-required messages are still active, and KSS blocks the requested action until they are acknowledged. In field practice it belongs to the system & program family of faults.

QCan I clear a KUKA 1020 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 KUKA documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by KUKA.