I’m needing to access data on an Siemens Logo via Modbus from my Flexy 201. I seem to be having trouble connecting to the Logo with Modbus. I test it with my laptop and it works but not with the EWon setup.
Hello,
What info are you using on you PC and what is the configuration used on the ewon?
You might be addressing the info differently. Do you see any error in the event logs? What are they?
Deryck
Good Morning Deryck,
I’m using ModScan32 on my laptop to just test the fact that I’m communicating with the Modbus Slave. The slave is a Siemens Logo. I’m just trying to access several IO and also Registers. I can see it with ModScan32 but the Ewon is having issues communicating with it.
I have attached screen shots of what my modbus setup is and the errors also.
I hope this helps.
Scott Foy
It looks like there is an error with the message it is getting back from the modbus server.
Do you get the same error if you read a holding register? Are you also reading from node 1 when using modscan32? Do you see any error message if you hover your mouse over the error notification on the tag view?
If you can setup a managed switch to mirror traffic from the flexy to you PC you could take a wire shark capture that would should you the exact what message is being send and received. This could show you what the difference is between modscan and the Flexy.
Deryck
Yes, I get the same error on a holding register.
Yes, I am reading from Node 1 with ModScan32.
The error message that I see when hovering over the error notification is “No communication”.
Scott
Are you able to setup something to capture a wireshark of the traffic? Or could you share login credentials to allow me to remote in and look over the setup?
Deryck
Yes sir, you are more than welcome to take a look:
That should give you admin rights.
Hope this helps!
Scott
I haven’t been able to stably get connected to the ewon. It looked like it might have a poor cell connection. Are you able to try and improve its connection so I can take a look?
I got as far as setting up a modbus tag before it dropped offline again.
Deryck
I think I got the connection issue worked out.
Give it a try please.
Scott
Still no luck.
Can you at least share a backup for me to look at?
Deryck
I tried sending you the backup but your email server kicked it out.
Scott
I gave the connection another try and was able to get on long enough to grab a wireshark capture. It looks like the ewon is having issue simply getting a connection to the Siemens PLC.
Would you be able to test this with out the Rockwell PLC connected too? Or at least with the ABlogix io server disabled?
Deryck
Good Morning Deryck,
I disconnected and disabled the AB processor from the eWon and it still doesn’t want to communicate. I also ran an isolated cable from the eWon to the Siemens Logo and I still get the same result.
Scott
Hi @HarleyMan2017,
Deryck is out until Thursday. Have you made any progress on this case? What is the latest?
Kyle
Hi Kyle,
I’m still waiting on what I need to do next. I did as Deryck suggested but didn’t have any luck.
Scott
Can you please share your Modscan settings
I have attached screenshots of my settings.
If you need to access it directly here are my ecatcher login credentials:
Hi Scott,
Here is a screen shot showing the only traffic I am seeing between the ewon and the Siemens device.
It seems like the ewon is trying to open a TCP connection for the modbus port but the siemens device is resetting the connection. I am not sure why this would be happening.
Can I disable the ABlogix IO server to try a capture with out the CIP traffic. I might not be capturing some of the modbus messages.
Deryck
Yes
It looks like it’s sending on port 502, but in the screenshot above I saw you were using port 503. Which is the Siemens device configured for?