Alarm List — Mori Seiki Ex

The machine is attempting to execute a command (like spindle rotation or rapid traverse) while the operator door is open or unlatched.

: Excess heat detected in the electrical control unit; check filters and cooling fans. EX0560 - Air Pressure Low

On a Mori Seiki machine, "EX" alarms (External Alarms) are specific to the machine's PLC (Programmable Logic Controller) rather than the underlying Fanuc or Siemens CNC system. They usually signal that a physical condition—like a door being open or a sensor failing—is preventing the machine from operating.

Cycle start was attempted while the Edit Key switch was still in the ON position. CHUCK UNCLAMPED mori seiki ex alarm list

The is more than a table of codes – it is a diagnostic roadmap into the machine’s PLC logic. While no single article can list every possible EX alarm (Mori Seiki has produced hundreds of control variants over 40+ years), the codes and categories covered here represent the vast majority of daily production stoppages.

Understanding these codes keeps your lathe or machining center running smoothly and minimizes expensive service calls. Understanding Mori Seiki Alarm Categories

The main pneumatic supply inlet pressure has dropped below the minimum requirement (typically ~0.5 MPa). The machine is attempting to execute a command

If it persists, re-examine the PMC diagnostics screen to see if another interlock condition remains unfulfilled. Preventive Maintenance to Reduce EX Alarms

Adjust the proximity sensors on the back of the hydraulic cylinder. Verify that your hydraulic pressure gauge reads within standard operating limits (usually 1.5 to 2.5 MPa). EX0351 / EX351: Hydraulic Pressure Down

These errors prevent the machine from machining an unsecured workpiece, preventing catastrophic parts ejection. They usually signal that a physical condition—like a

Check for a mechanical jam or heavy chips jammed behind the turret disk. Verify hydraulic pressure. You may need to perform a turret zero-return or alignment procedure using Mori Seiki custom parameters or M-codes (like M43/M44 on older machines). Universal Troubleshooting Steps for Mori Seiki EX Alarms

The way lube pressure did not reach the required threshold within a set time after the pump turned on.

Hydraulic pressure dropped below the safe operating limit (usually required for chucking, tailstock, and tool unclamp).