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ABB Error 20011 — Emergency stop chain conflict

Error

ABB 20011 (“Emergency stop chain conflict”): The two channels of the e-stop chain disagree (one open, one closed).

Updated 2026-09-17 · LogrobotLM reference

What it means

The two channels of the e-stop chain disagree (one open, one closed). This is a hardware integrity fault of the safety chain — not a normal stop.

What to check

  • Test both channels of each device in the chain (buttons, relays, connectors).
  • Look for a chattering contact or damaged cable — the mismatch usually sits at ONE device.
  • Never bridge a safety channel to “test” — replace the faulty device.

Related codes

20010Emergency stop status10013Emergency stop state

Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →