Okuma Alarm A-1721 – Gear Neutral

Okuma Alarm A-1721 Gear Neutral appears when the CNC control receives a spindle rotation command (such as M03 or M04) while the spindle drive gearbox is in neutral position. In this state the spindle cannot transmit rotation from the motor to the spindle shaft, therefore the control system stops the operation and generates the alarm. This usually happens when the gearbox has not fully engaged a gear, when the machine is still switching gear ranges, or when there is a problem with the gear shift mechanism or sensors. Checking the gearbox position, ensuring that the correct gear range is engaged, and restarting the machine can sometimes resolve the issue. If the alarm continues to appear, the spindle gearbox or the gear shifting system may require inspection or adjustment.