When opening a VNC service, it doesn't work at all. It may show one of the following errors:

The upstream server is not responding (514)

The operation could not be performed because the upstream server does not appear to exist. (519)

This article will provide help in troubleshooting the VNC service, finding the cause, and solving the problem.

If the VNC service works but it is partially black, see instead VNC is partially or largely black.

This can have a wide range of causes, such as a forgotten configuration push, incorrect settings, or no reachable device.

The error message you see in the IXON Cloud when opening the VNC service does not contain any useful information. As such, the solution can only be found by going over a few checks instead.

Check the following first.

1. Check status.ixon.cloud to see if there is an active disruption.

If there is no service disruption, proceed below. It may solve the issue without further troubleshooting.

2. Go to Fleet Manager > Devices and click on your device name.
3. In the top right corner, check if the configuration is in sync.

   Configuration is in sync:		Configuration is not in sync:

4. If the configuration is not in sync, click on Push device config.
   • The edge gateway may temporarily disconnect and LAN communication may be temporarily interrupted while it's applying the new settings. This only takes a moment.

This may have already fixed the issue. Wait a brief moment to make sure the changes are applied and then proceed to test whether the VNC service works now. If it still does not work, proceed below.

5. Set up a VPN connection to your edge gateway.
6. Open a VNC viewer, like TightVNC, RealVNC, or even Siemens' Sm@rtClient, and connect to the IP address of your machine.
7. Does the VNC server open or do you see an error appear? If you see an error, select the error below for help. If it opens without problems, proceed below.
   Timeout error / connection refused / failed to connect

   There is no VNC server running on that IP address.

   • Verify that the IP address you entered matches with the IP address configured on the HMI.
   • Verify that the VNC server is actively running on the HMI. For assistance, please contact the manufacturer.
   • Verify that the VNC server is running with the correct settings. For specifics, see "Prepare the machine" in "Remote control panel access using VNC EasyControl".

   On Weintek HMI's we've observed the issue that VNC was inexplicably turned off. If this happened to you, report the issue to Weintek and turn VNC back on in the HMI's settings to restore your connectivity.
   Authentication failed

   The password is incorrect or the password on the VNC server is too long.

   • Verify that the password is correct.
   • Make sure that the password on the VNC server is max 8 characters long. VNC supports passwords up to 8 characters.
   • Certain special characters are not supported (e.g. ë, á, ì).
   Reading version failed: not an RFB server? (RealVNC Viewer)

   The VNC server is running, but it is not correctly configured.

   • In the Sm@rtServer settings on the Siemens HMI, make sure the setting "Encrypt communication" is turned OFF.
   SSL handshake failed (Siemens Sm@rtClient)

   There is a VNC error on the Siemens HMI.

   • Physically on the Siemens HMI, turn the runtime OFF and back ON.
   • Install the latest firmware on the Siemens HMI.

If you addressed an error, that may have fixed the issue. Test whether the VNC service works now. If it still does not work, proceed below.

8. Go to Fleet Manager > Devices and click on your device name.
9. In the left menu, go to Services.
10. Click on the VNC service.
11. Check the entered IP address and verify that it is the correct IP address of your machine.
    • Tip: This is the IP address where the VNC server can be reached. Leave empty for localhost, if you're using an IXagent, or if this service is for a Docker container on a SecureEdge Pro.
12. Check the entered Port and verify that it is the correct port for your VNC server.
    • Tip: The default port for VNC is port 5900.
13. Check the entered Username and verify that it is correct.
    • Tip: If you were prompted to enter a username when connecting to the VNC server over the VPN connection, that username needs to be entered here as well. It is not possible to receive a username prompt while connecting.
14. Check the entered Password and verify that it is correct.
    • Tip: If you were prompted to enter a password when connecting to the VNC server over the VPN connection, that password needs to be entered here as well. It is not possible to receive a password prompt while connecting.
15. Check the entered Encoding and verify that it is correct.
    • Tip: For Lenze hardware, set this to Hextile.
16. Check the entered Color depth and verify that it is correct.
    • Tip: For B&R hardware, set this to what is set on your B&R device (default is 8-bit).
    • Tip: For VIPA hardware, set this to what is set on your VIPA device (default is 32-bit).
17. If you made a change in the VNC service settings, don't forget to Confirm changes and then Push device config.
    • The edge gateway may temporarily disconnect and LAN communication may be temporarily interrupted while it's applying the new settings. This only takes a moment.

If your issue is still not resolved, please contact us and grant us support access for at least 7 days at Fleet Manager > Tools. Please include in your message: a clear problem description, what you've already checked and done, the edge gateway serial number, and the VNC service name. We will then investigate the issue and get back to you.