PROFINET Communication Fault on NexBot Safety FLR022-008

Description

We are attempting to integrate a new NXB-ROB-FLR022-008 collaborative robot into our assembly line controlled by our central PLC. We have installed the correct GSDML file provided by NexBot into our engineering station and configured the robot as a PROFINET IO device. The robot is powered on with 48VDC and connected to the PROFINET network, but the PLC is reporting a bus fault and cannot establish communication. We have verified the IP address is set correctly on the robot controller and is on the same subnet as the PLC. We have also triple-checked the ethernet cabling between the controller and the network switch. The robot operates correctly when controlled manually via the teach pendant, but it is not visible to the master PLC. The PROFINET status LED on the robot controller is flashing amber, which the manual indicates is a configuration or connection error. We need to get this resolved to proceed with line commissioning.

Symptoms

• PLC reports a PROFINET bus fault for the robot's node.
• Robot controller's PROFINET status light is flashing amber.
• Robot is not listed as a connected device in the PLC's online diagnostics.
• Unable to exchange I/O data between the PLC and the robot.

Resolution

The issue was traced to a mismatch in the PROFINET Device Name. While the IP address was correctly configured, the robot controller's PROFINET station name was still set to its factory default ('nexbot-default'). The PLC project was configured to look for a specific device name ('welding-station-cobot-1'). PROFINET requires both the IP address and the Device Name to match between the physical device and the PLC's hardware configuration for communication to be established. Once the robot's Device Name was updated using the NexBot configuration software to match the name in the PLC project, communication was successfully established after a power cycle of both devices.

Resolution Steps

1. Connect a PC to the robot controller's service ethernet port.
2. Launch the NexBot Configuration Utility software.
3. Navigate to the 'Network Configuration' > 'PROFINET Settings' section.
4. Confirm the IP address settings are correct for the target network.
5. In the 'Device Name' field, change the value from the default to the exact name specified in the PLC hardware configuration.
6. Save the new configuration to the robot controller. The controller will prompt for a reboot.
7. After the robot controller has fully rebooted, perform a power cycle on the master PLC to re-initialize the network.
8. Verify that the robot controller's PROFINET status light is now solid green and the bus fault is cleared on the PLC.