Axis 2 Drive Fault on LA013-008 Robot Arm

Description

Our NexBot Safety LA013-008 robot arm, which is used for palletizing heavy castings, has stopped mid-cycle and is showing an error on the teach pendant. The error code is E-4502, which our manual indicates is an Axis 2 Drive Communication Lost fault. We have attempted a full power cycle of the robot controller and the cell PLC, but the fault returns immediately upon startup. We are unable to jog any axis, but Axis 2 seems to be the source of the problem. The robot is completely down, and this has halted our entire end-of-line packaging process. We have checked the main 480VAC supply and all breakers are fine. The EtherCAT status lights on the main controller node are green, but we cannot see the status on the drive itself without opening the cabinet. We need immediate assistance to diagnose whether this is a drive, motor, or cabling issue to get our line running again.

Symptoms

• Robot stopped mid-cycle and will not restart.
• Teach pendant displays error E-4502: Axis 2 Drive Communication Lost.
• Unable to jog Axis 2 manually.
• Red fault light illuminated on the robot controller cabinet.

Resolution

After remote diagnostics with the customer, it was determined that the Axis 2 servo drive amplifier inside the R-50 controller cabinet was faulty. Initial troubleshooting steps, including checking EtherCAT cable connections and verifying input power, did not resolve the issue. The drive's internal diagnostics were not responding, confirming an internal failure. A replacement Axis 2 Servo Drive (Part # NXB-DRV-A2-R50) was dispatched via overnight service. The customer's on-site maintenance team successfully replaced the unit, re-addressed the drive on the EtherCAT network, and restored the robot configuration from a backup. The robot passed all calibration and functional tests and was returned to service.

Resolution Steps

1. 1. Instructed the customer to perform a full Lockout/Tagout (LOTO) procedure on the robot cell.
2. 2. Guided the customer to open the R-50 controller cabinet and visually inspect the Axis 2 drive for any signs of damage or loose connections.
3. 3. Had the customer swap the EtherCAT cables between the Axis 2 and Axis 3 drives to rule out a cable failure. The E-4502 fault remained on Axis 2.
4. 4. Confirmed the drive was receiving correct 480VAC input but was not initializing, indicating an internal hardware failure.
5. 5. Shipped a replacement Axis 2 Servo Drive, SKU: NXB-DRV-A2-R50.
6. 6. Provided instructions for removing the faulty drive and installing the new one, ensuring all power and communication cables were securely reconnected.
7. 7. Walked the customer through the software procedure to commission the new drive and load the correct motor parameters.
8. 8. The fault was cleared, and the robot was successfully re-calibrated and tested before removing LOTO and resuming production.