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NEPI Engine – Software Troubleshooting

Startup Issues

RUI Connection Issues

1) Check that your PC’s Ethernet adapter is properly set to the same subdomain as the NEPI device you are connecting to.  For defualt NEPI installations the recommended PC IP address and netmask is &

2) Open a terminal (Command Prompt on Windows), and try pinging the NEPI device by typing:   


3)  If you can’t connect to your RUI, or the RUI keeps giving the message “Error connecting to NEPI device, retrying”, your active NEPI File System may be currupted.  You can try switching to your NEPI device’s backup File System through an SSH connected terminal (see the NEPI Engine – Accessing the File System tutorial for instructions).

SSH into your NEPI device’s File System and manually send a “switch active partition” command by typing:

rostopic pub /nepi/s2x/switch_active_inactive_rootfs std_msgs/Empty "{}"

Then restart your system, which will now boot into your device’s backup NEPI File System.  If this works, you should switch back to the original bad partition using the same command above, archive your good partition that is now inactive by typing:

rostopic pub /nepi/s2x/archive_inactive_rootfs std_msgs/Empty "{}"

Wait for the new NEPI File System image archive file to stop growing on your NEPI user drive at:


Then switch back to your good partition using the original command above, reboot your system.  After boot up, move your archived image from the archive folder to the NEPI File System install folder at:


and use the “Restore Image” button in the NEPI RUI’s Software tab to apply your good image to the bad partition. then reboot one last time.

USB 3 Device Connection Issues

1) Make sure your device is connected with a quality USB3 cable.

2) Try connecting the USB device into a different USB port on your NEPI device.

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