Codesys PLC can not go online

Hey guys,

I am using a linux arm based device as PLC and I am running the demo runtime on it. I was able to go online earlier and download the program and test it. But after a few days when I try to go online the PLC software can be scanned through scan network screen but when I select the device I get " No device is responding to the scan request" . Can you tell me what can be done? I even tried to create a new program and connect to it but I still get the same error.

I am attaching a few pictures for clarification.

Thanks
SB

That is normal, in my experience.

When you have only the demo runtime, it will execute for about 2 hours, then shut down and stop working, including for communications features. It does not simply put the CoDeSys runtime into STOP mode.

When I am using demo runtimes, I go online via a console or SSH and restart the CoDeSys runtime from the command line, or simply do an orderly "sudo reboot" command.


For many single-board computers, it's not very risky to simply cycle power, since I can create a fresh SD card in a few minutes. Otherwise, I do software reboots.

Hi Ken,

Actually I tried a bunch of things, did a restart - dint work. Deleted the boot application and restart - dint work. Do you have any other ideas that I can try may be

Thank you!

does the scan yield an IP address for the PLC?


does the [Wink] button work?


Google may provide some answers; I poked around and found some posts on various sites with similar issues and some solutions.

Sometimes the Device scan doesn't work. Usually putting the ip address of the device in the drop down on the right side of the Device Scan page works.

ndzied1 said:

Sometimes the Device scan doesn't work. Usually putting the ip address of the device in the drop down on the right side of the Device Scan page works.

Click to expand...

Totally agree with this. I have been using Codesys for a long time and I always use the IP address of the Raspi and do not bother scanning for Codesys devices. If your Raspi has WiFi, the best practice for me is to program the WiFi router so as to assign a fixed IP address to the Raspi, then you never need to worry about scanning for the Raspi, just use the fixed IP address, which has the additional advantage of allowing you to access the Raspi not only with the Codesys engineering tool, but also any visualization screen that you have mapped onto the Codesys web server, which is handy for testing and demo.

Something like this...

Thank you all for the great help. Alfredo/ndzied1 I did your method of directly entering the IP address and it works. Strange why it would scan the device but not accept it.
Anyways as always I am really grateful to be on this forum with so many knowledgeable people helping each other out.

Great that you sorted it. I always turn on classic view here. It always somehow seems more comfortable. Tools > Options > Device Editor > Communication Page > Classic Mode