Ewon Cosy 4G to Rockwell PLC very slow

I have an Ewon Cosy 131 4G unit, serial number 2045-0196-22, Firmware 14.3s0
I am based in Scotland, and the Ewon is installed in China. Everything is connected and the 4G signal strength is shown as Maximum.
The Ewon is linked to a network containing some Nidec inverter drives, and two Rockwell Compactlogix PLCs. I can ping all the items with the round trip time approximately 400ms.
Communications with the PLCs is very slow with a screen update taking about 5 seconds if it works, but it often drops the connection (within the Rockwell software).

Note the Ewon router is type EC6133G (the EU version) as this was easily available in China.

Are there any checks I can do to see why the the communication with the PLC is so unstable?


Hi Paul,

Do you have the Ewon set to use TCP instead of the default UDP?

If you run through the final wizard and set it to TCP the device will temporarily become unavailable while it tries the connection. If it fails it will just revert back to the previously used UDP connection.

UDP connections are good for real time data but don’t have any packet correction so if you’re trying to connect and download to a PLC, then I recommend using a TCP connection

You can verify that the TCP connection was successful once the device comes back up by checking this area and making sure that the vpnportout has a value of 443 instead of the 1194 that UDP uses.


Hi Tim,

Thank you for your reply. I have changed the Ewon to TCP. This has certainly helped. The has improved the communications but I still have frequent drop outs. Note the drop out is between my PC and the PLC, I always have a good connection to the Ewon. Do you have any other suggestions? I think the issue is with the PLC communications driver, but is there any diagnostics to see if I can determine what is happening?

This is an EU router in China. Does this make any difference? Is the only difference the 4G bands it can connect to or is there anything else that may be causing the issue?

Does the device seem to consistently respond to pings while you’re connected or do those seem to drop out as well?

If the Ewon is staying online, then you should be able to keep reaching the PLC

The ping does drop occasionally. Generally the ping will reply 3 out of the 4 times for a standard ping message.

In that case I’m not sure how much more we’d be able to do other than have them try to get the device a stronger internet access. Can you get a backup.tar file of the device with the support files included from eBuddy so we can check the signal strength of this device?