VNC connection to the X20 PLC VNC server


Hi, I am trying to connect to the X20 PLC (CP 0482 model) VNC server which I had set up. The PLC program is running, and I can ping the IF2 ethernet port. However when I use a VNC client to connect (B&R VNC Viewer) I get the following message:
“The connection parameters cannot be set.
An operation was attempted on something that is not a socket.”

I believe I have set up the IF2 configuration (VNC Servers section) correctly. Does anyone have a solution to this issue ?

Hi greg, Very likely is something else running on the same port, so at the beginning try to change port on VNC server side and on the client side use ip address together with port in format



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Thank you @kovarj , I can now connect to the VNC server.


Hello @kovarj, as a follow-up to my VNC issue last week, I now get the following issue with VNC Viewer when I try to view the VC4 pages (from error log):

13-05-2024 09:31:04.779 B&R VNC Viewer version 4.3
13-05-2024 09:31:12.713 Device connected. Starting VNC …
13-05-2024 09:31:13.253 RFB server supports protocol version 3.3
13-05-2024 09:31:13.253 Connected to RFB server, using protocol version 1.0
13-05-2024 09:31:13.255 No authentication needed
13-05-2024 09:31:13.304 Desktop name “Test HMI pages”
13-05-2024 09:31:13.864 Cannot read from socket: error 10054
13-05-2024 09:31:13.864 ReadScreenUpdate failed with error 10054
13-05-2024 09:31:13.864 Viewer closed from update-processing thread: error 10054, killthread 0

I have a lot to learn with the B&R Automation software/hardware family (never used it before, mainly used Rockwell products in the past). Any help will be greatly appreciated !

Update: It seems I’m running into a memory issue. I see the following in the online Info:

Can I change memory optimisations, or do I need another solution ?

The SDM also gives these messages:

Hi, yes…you do not have enough free memory. There are two ways how to fix it, or better say three:
a) simplify your visualization, probably is to complex, if you use pictures try to reduce resolution o f it.
b) you can try to get more memory if you disable functionality like SDM etc (I do not like it, but can help you. Check CPU-> configuration and what services are enabled
c) the best one. Use PLC with more DRAM. Then you can have complex visu and all services like SDM enabled.

Thank you. I was running the coffee machine example. I started another simple example which runs as expected.

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