Mori Seiki Ex Alarm List ((exclusive)) -

EX alarm list for Mori Seiki CNC machines typically refers to external alarms

generated by the machine's Programmable Logic Controller (PLC) rather than the base Fanuc or Mitsubishi control

. These alarms often relate to machine-specific mechanical conditions, safety interlocks, and auxiliary equipment. Common Mori Seiki EX Alarms EX0006 - Wrong Combination of M-Codes : An invalid set of M-commands was given simultaneously. EX0018 - Need Zero-Return

: A cycle start was attempted without completing the necessary X or Z-axis zero returns. EX0024 - Chuck Unclamped

: Cycle start activated while the chuck was not securely clamped. EX0026 - Door Not Closed : The machine door is open during a cycle start attempt. EX0029 - Tailstock Inching / Quill Not Out

: Attempted cycle start during tailstock movement or with the quill in the wrong position. EX0069 - Door Lock Check Time Over mori seiki ex alarm list

: The system did not receive a door lock confirmation within the expected timeframe. EX0095 - Turret Illegal Movement

: The turret attempted to move without a valid command; often requires checking the output driver or clamp signals. EX0099 - Panel Alarm

: General error related to the operator panel or its power supply. EX0491 - Spindle Speed Abnormal

: The actual spindle RPM deviates significantly from the programmed speed; often caused by mechanical resistance or sensor issues. EX0551 - Electrical Cabinet Overheat

: Excess heat detected in the electrical control unit; check filters and cooling fans. EX0560 - Air Pressure Low EX alarm list for Mori Seiki CNC machines

: The incoming air pressure has dropped below the operational threshold. EX1047 - PMC Parameter Error

: Often indicates that PC spec parameters have been cleared or corrupted. General Troubleshooting Steps Check Physical Conditions : Verify air and hydraulic pressures are stable under load. Inspect Sensors

: On legacy machines, aging or dirty proximity sensors (especially on the ATC, turret, or door) are the most common cause of EX alarms. Review I/O Status

: Use the diagnostic or PMC/I/O status screens to see which signal the PLC is missing. Reference Manuals

: Because EX codes are machine-specific (e.g., a DuraVertical vs. an NL-series lathe), always consult the Operation Manual Ladder Diagram specific to your serial number for exact definitions. Are you currently seeing a specific alarm code on your screen, and what machine model are you working on? bearing issue. First-line actions: Allow cooldown

top Legacy Mori Seiki CNC Error Codes Explained & How To Fix

The Ultimate Guide to the Mori Seiki EX Alarm List: Causes, Solutions, and Prevention

Part 5: Step-by-Step Troubleshooting for Top 5 EX Alarms

Preventive maintenance to reduce alarms

• Regular lubrication and mechanical inspection (ways, ballscrews, turrets).
• Keep cables and connectors secured; check for wear and contamination.
• Monitor coolant levels, filters, and cleanliness.
• Maintain proper ambient temperature and ventilation for drives.
• Periodic encoder and servo tuning checks; update firmware per OEM guidance.
• Backup parameters and programs frequently.

4. Spindle Alarms

• Alarm: 4001 / SPINDLE OVERSPEED

  • Description: Spindle speed exceeds set limit.
  • Typical causes: Faulty tachometer, control error.
  • First-line actions: Stop spindle, verify speed command and sensor, check drive signals.

• Alarm: 4010 / SPINDLE OVERHEAT

  • Description: Spindle temperature too high.
  • Typical causes: Inadequate cooling, heavy cut, bearing issue.
  • First-line actions: Allow cooldown, check coolant flow and fan operation, inspect spindle bearings.

Part 3: The Most Common Mori Seiki EX Alarm Codes (By Category)

Based on decades of field service reports, the following EX alarms represent over 80% of service calls. This curated list is a practical starting point before you open the full service manual.