ModbusPal runing problem on Ubuntu 20.04

General Installation
1

Hi,

I’m not sure if I should put the question here, but it is related to Tango, so maybe someone happened to experience it before.

I installed ModbusPal(ver.1.6b,Modbus simulator) on a real Ubuntu/20.04 as it is on the VirtualBox9.3. However, after clicking on the “Run” button on the screen of ModbusPal, all buttons “die”, the only thing I could do is to kill the ModbusPal on the terminal. I also tried ModbusPal(Ver.1.6c), the case is the same except it shows on the terminal :“Could not load initial port number. Loading defaut port number”.

It looks the ModbusPal failed to open the default port 502. Following is what action I took on this:

  1. I use the super user command " sudo java -jar ModbusPal.jar" to start the ModbusPal.
  2. The firewall on ubuntu is inactive,
  3. The SElinux is stopped.
  4. “sudo ss -ntlp | grep LISTEN” shows that the port 502 is not taken by other application.
  5. OS: Unbuntu/20.04, Java version:1.8.0_392, Modbupal ver.1.6b and 1.6c.

I did a lot of research on this issue, but still don’t have any clue, so is there any body happened to experience this issue?

Thanks
Ding

2

Hi Ding,

This does not look like a Tango related issue.
Maybe you can try to get some help directly from ModbusPal project?

Kind regards,
Reynald

3

[quote=“Reynald”]Hi Ding,

This does not look like a Tango related issue.
Maybe you can try to get some help directly from ModbusPal project?

Kind regards,
Reynald[/quote]

Hi Reynal,

Thank you for the help. Yes, you are right, it has nothing to do with Tango, and it actually is the issue of ModbusPal with Linux. I just tried to replica the Tango demo of VirtualBox 9.3, where the ModbusPal runs well. I’ll seek help from ModbusPal website and see the result.

Regards,
Ding