What causes KUKA Robot alarm KRC0331?

Broken or corroded servo enable cable connection between drive cabinet and KRC controller. Faulty servo drive enable output or defective servo drive module. Loose or improperly seated connector pins on the servo ready input terminal. Voltage drop due to damaged wiring harness or poor grounding in the servo circuit. Defective input module or damaged analog/digital input card on the KRC controller.

How do I fix KUKA Robot alarm KRC0331?

1. Power down the robot system completely and verify all emergency stops are engaged before inspecting connections 2. Visually inspect the servo enable cable from the drive cabinet to the KRC controller for physical damage, kinks, or corrosion 3. Disconnect and reconnect the servo ready input connector on the KRC controller, ensuring it is fully seated and locked 4. Use a multimeter to measure the voltage at the $SERVO_RDY input terminal; verify it matches the specified signal level (typically 24 VDC) 5. Check the servo drive output signal by measuring voltage at the drive cabinet servo enable output terminal while powered 6. If voltage is present at the drive but not reaching the controller, replace the servo enable cable; if voltage is absent at the drive, service or replace the affected servo drive module

KUKA Robot codes

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KUKA Robot Controller

Servo/Axis · Advanced

Alarm KRC0331

KUKA Robot KRC0331 - ACKN. GENERAL SERVO ENABLE

This alarm indicates that the servo enable signal ($SERVO_RDY) at the KRC controller input has dropped below the required voltage threshold, preventing the robot from receiving a valid servo ready confirmation from the drive system. The servo enable signal is critical for establishing safe communication between the controller and the axis servo drives, and a low signal state blocks all axis motion commands.

KUKA RobotServo/AxisAdvanced

KRC0331

KUKA Robot KRC0331 - ACKN. GENERAL SERVO ENABLE

ACKN. GENERAL SERVO ENABLE

Common Causes

Broken or corroded servo enable cable connection between drive cabinet and KRC controller
Faulty servo drive enable output or defective servo drive module
Loose or improperly seated connector pins on the servo ready input terminal
Voltage drop due to damaged wiring harness or poor grounding in the servo circuit
Defective input module or damaged analog/digital input card on the KRC controller

Troubleshooting Steps

1Power down the robot system completely and verify all emergency stops are engaged before inspecting connections
2Visually inspect the servo enable cable from the drive cabinet to the KRC controller for physical damage, kinks, or corrosion
3Disconnect and reconnect the servo ready input connector on the KRC controller, ensuring it is fully seated and locked
4Use a multimeter to measure the voltage at the $SERVO_RDY input terminal; verify it matches the specified signal level (typically 24 VDC)
5Check the servo drive output signal by measuring voltage at the drive cabinet servo enable output terminal while powered
6If voltage is present at the drive but not reaching the controller, replace the servo enable cable; if voltage is absent at the drive, service or replace the affected servo drive module

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