Connection troubleshooting

Find out why your PC cannot reach the controller or its application, one check at a time.

3 minute read

A connection problem is easiest to find from the bottom up: each check only makes sense when the one before it passes. Start at the first check, and stop at the first one that fails. Click a check to jump to it.

Check the cable

The controller is switched on, or the virtual machine is running.
The network cable is plugged in at both ends, into the network port of the controller that faces your PC. On most network ports a light comes on when the link is up.
Try another cable or another network port on your PC. A USB network adapter can also be at fault.

Check your address

The network port with the cable must have an address on the controller’s network, for example 192.168.2.26. Look it up:

System	Command	Look for
Ubuntu	`ip -4 addr`	`inet 192.168.2.26/24` under the wired port, for example `enp3s0`
Windows	`ipconfig`	`IPv4 Address` and `Subnet Mask` under the `Ethernet adapter`
macOS	`ifconfig`	`inet 192.168.2.26 netmask 0xffffff00` under the wired port, for example `en5`

If the port has no address, or one on another network, set it again as in Configure your network.

Only one network port of your PC may be on 192.168.2.x. If Wi-Fi or a second adapter uses the same network, your PC may send the traffic there. Disconnect the other one while you work with the controller.

Ubuntu keeps an old wired connection

If Ubuntu keeps coming back with the wrong settings, remove the saved wired connection and set it up again.

Unplug the network cable.
List the saved connections:
```
nmcli connection show
```

Delete the wired one, for example Wired connection 1:

sudo nmcli connection delete "Wired connection 1"

Plug the cable back in and configure your network again.

Ping the controller

When the address is right, check that the controller answers. On Ubuntu and macOS:

ping -c 5 controller_ip_address

On Windows:

ping -n 5 controller_ip_address

All five should come back, with 0% packet loss in the summary.

Ubuntu terminal: ping to the controller with five replies and 0% packet loss

If none come back while your address is right, the controller may have been given another address. See Network configuration.

Check the certificate

If the ping works but the browser shows a security warning, such as NET::ERR_CERT_AUTHORITY_INVALID, your browser does not trust the controller yet. Install the certificate as in Install a browser certificate, then close and reopen the browser.

Check the application

If the page opens with a padlock but the tools cannot connect, the Motorcortex application on the controller may not be running.

Log in to the controller as in Remote access and file transfer.
See whether the application runs:
```
sudo systemctl status motorcortex
```
Restart it:
```
sudo systemctl restart motorcortex
```
Warning

Restarting the application stops everything it controls. Make sure no machine is moving first.
Connect again from your browser. If the application stops again, its errors must be fixed first; sudo systemctl status motorcortex shows the last messages.

Check firewalls

If every check above passes and the tools still cannot connect, security software on your PC or a firewall between your PC and the controller may block the connection. Allow these ports to the controller, or connect your PC straight to the controller with a cable:

Port	Used for
`443`	HTTPS: the pages the controller serves
`5568`	WSS: requests from the tools to the application
`5567`	WSS: live data from the application to the tools
`22`	SSH and SFTP