What the 1030 alarm means

In AUT/EXT mode the controller expects an external START edge that never arrived, so the selected program does not run. This is a fault we handle frequently on KUKA KRC2 / KRC4 / KRC5 (KSS) systems — in most cases we can pin down the root cause on the first site visit.

Most common causes

  • Start button or PLC start bit not asserted, or not edge-triggered
  • $EXT_START polarity changed after a KSS upgrade (behavior differs between KSS 8.2 and 8.3+)
  • START input wiring broken
  • Program not in reset state (pointer not at main)
Field note: The first item on this list is what we hit most often on real machines — clear that one before going deeper.

Step-by-step field fix

  1. Verify the PLC or start button actually toggles the $EXT_START input
  2. Use an edge-triggered start pulse in the SPS, not a latched signal
  3. Check the KSS version notes if the cell was recently upgraded
  4. Set the program pointer to main (PP to main) before starting
Safety first: For KUKA 1030, the risk on this family is not injury but data: lose the program, parameters and calibration data and weeks of teaching work start over. On site you may carry out the first step yourself: Verify the PLC or start button actually toggles the $EXT_START input. Beyond that it is program and calibration data work - leave it to a professional.

How we diagnose system alarms on site

KUKA 1030 belongs to the system & program family. On KUKA 1030 the failing stage is KSS (KUKA System Software) (KRC2 / KRC4 / KRC5) on the KRC2 / KRC4 / KRC5 - the software layer: corrupted program or parameter files, boot failures, version mismatch, memory and storage media. We start reading KUKA 1030 at the smartPAD message window (KSS message numbers: 1xxx operator, 2xxxx drive) with KPP/KSP module LEDs.

The chain involved in KUKA 1030 runs: storage media (CF / flash / disk) -> system software and firmware -> parameters and calibration data -> user programs -> runtime.

KUKA 1030 is a system-family alarm, and our iron rule is: On system alarms we have an iron rule: however urgent the customer is, we take a complete backup first - programs, parameters, calibration data, tool and work-object frames, all of it. The reason is arithmetic: losing the live state here usually means weeks of teaching done again, which costs far more than a few hours of downtime. Only after the backup do we decide restart, restore or reinstall. If the storage media is already throwing errors we pull the data read-only first.

Field notes on this page cover KUKA 1030 (External Start Missing ($EXT_START)); written by the Henghuan repair team, updated 2026-10-01.

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Related System & Program alarms

1004 — File System Error 1015 — No Program Selected 1020 — Pending Message Not Acknowledged ($CONF_MESS) 15102 — SmartPad (Teach Pendant) Fault
Same family: this code belongs to the System & program alarms family - the page collects all System & program-family codes we have handled, with the common inspection order and spares.
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 1030 alarm mean?

In AUT/EXT mode the controller expects an external START edge that never arrived, so the selected program does not run. This is a fault we handle frequently on KUKA KRC2 / KRC4 / KRC5 (KSS) systems — in most cases we can pin down the root cause on the first site visit. KUKA 1030 sits in the system & program family; on our work orders the highest-frequency trigger for this code is "Start button or PLC start bit not asserted, or not edge-triggered".

QCan I clear a KUKA 1030 alarm myself?

Whether KUKA 1030 clears on its own depends on the outcome of "Verify the PLC or start button actually toggles the $EXT_START input". Finish the flow with "Set the program pointer to main (PP to main) before starting" to confirm KUKA 1030 - do not skip it. If that step is clean, the second most frequent cause on KUKA 1030 is "$EXT_START polarity changed after a KSS upgrade (behavior differs between KSS 8.2 and 8.3+)". When KUKA 1030 keeps coming back it is not a one-off trigger - especially if Set the program pointer to main (PP to main) before starting is where you get stuck. Do not keep producing through KUKA 1030.

QWhen you handle KUKA 1030, will my programs and frames get lost?

The commonest causes we see on KUKA 1030 are "Start button or PLC start bit not asserted, or not edge-triggered, $EXT_START polarity changed after a KSS upgrade (behavior differs between KSS 8.2 and 8.3+), START input wiring broken", so we stock the van against those. For KUKA 1030 specifically, we carry recovery media and common storage media, but on this family the backup matters more than the spare. For KUKA 1030, on system alarms the first move is backup; we can walk the customer through preserving data remotely before anything else. Before we roll, tell us what KUKA 1030 shows on the smartPAD message window (KSS message numbers: 1xxx operator, 2xxxx drive) with KPP/KSP module LEDs and what the machine was doing - phone or video triage is free.

This page on KUKA 1030 is based on the field experience of the Henghuan Robotics repair team. Alarm explanations are our own summary for troubleshooting reference and may differ across controller and software versions — if unsure, verify against KUKA documentation or reach out to us. Henghuan is an independent service provider with no affiliation or endorsement by KUKA.