APM
All alarm codes
ALARM 3

EMERGENCY STOP (&0000FFBF)

Multiple possible causes — door interlock, drive ready signal missing, external E-stop loop break, chip conveyor, etc. The R69 interface signal byte indicate...

Controls
Mazatrol Matrix Nexus
Machine series
unspecified Matrix Nexus lathe

Causes

  1. Multiple possible causes — door interlock, drive ready signal missing, external E-stop loop break, chip conveyor, etc. The R69 interface signal byte indicates which gate is open.

    • Fabian Achavalyoutube
      There are many problems that can cause an EMERGENCY STOP alarm. Understanding the alarm page message and the interface signals can help determine the cause.

How to clear it

  1. 1

    Open the alarm page and read the &0000FFBF hex string; then open the diagnostics for R69 interface signals to identify which bit is asserted, and chase that physical interlock.

    • Fabian Achavalyoutube
      Understanding the alarm page message and the interface signals can help determine the cause.

Confidence: medium · Source explains the diagnostic *method* (R69 interface signals) but the specific physical fix depends on which bit is asserted — no single root cause.

First sourced: 5/21/2026