FOR TIPS, gUIDES & TUTORIALS

subscribe to our Youtube

GO TO YOUTUBE

14455 questions

17168 answers

28195 comments

0 members

We are migrating to our new platform at https://community.teltonika.lt. Moving forward, you can continue discussions on this new platform. This current platform will be temporarily maintained for reference purposes.
0 votes
449 views 9 comments
by
As I am fetching data from Modbus tcp slave to my Qt application. I notice something weird behavior with Modbus Tcp slave. For testing purpose, I was removing the ethernet cable from the module, and almost after a few hours I was again doing the same testing with a fresh launch of my Qt application but this time there is no data coming from Modbus then after If I reboot the module again the data receiving is starting. At the same time, I was testing the same thing on my other machine with the same Qt application, there also noticed that there is no data coming from the Modbus.

This is happening every day.

So I don't understand why this is happening. Please resolve this issue ASAP.

1 Answer

0 votes
by anonymous
Hello,

Could you provide more information about your Qt application(provide a link to it). Also, are you sure this is a TRB245 issue and not an application issue? Have you tested it like that with other devices? By saying you are restarting the module do you have TRB245 in mind?

Regards.
by
Yes because daily I am facing the same issue and to get rid of that I need to restart the TRB245 module. My Qt application is just reading the Signal Strength value through Modbus TCP slave. Once I thought the problem is coming from my Qt application so to check this I put my application in running mode while Modbus in a hang situation and I restarted the TRB245 module, after restarting of the TRB245 module I was able to receive data on same application which was running when the Modbus not able send the data.
by anonymous
Please provide a link to your Modbus TCP master application, we will do some testing.
by
I can't provide you the link of my application because for that I need to remove the other functionality.
by anonymous
Understandable, maybe do you have another one of our devices that you could test with that application or could you test TRB245 with other public applications?
by
I don't have another unit and not even another application to test Modbus.

Like I said earlier, I was doing some test cases like removing ethernet cable from the TRB245 module for some minutes and doing this for serval times. After a few hours later I was facing this issue and I don't think so it's a problem with Qt application because after a restart of the TRB245 module I able to receive the data on the same application which was not able to receive earlier.

Even I try to close my application and relaunch it when it's not receiving any data from the TRB245, still I was facing that problem. It's only getting recovered after the TRB245 reboot.
by anonymous
Have you tried to turn on/off the "Keep persistent connection" option or changing the "Timeout" value in the Modbus TCP Slave configuration window?
by
No, I need the "keep persistent connection" option. I didn't set any Timeout value.
by anonymous

We made some tests with publicly available applications to test your use case. 

First, we used Linux PC and the modpoll application to emulate Modbus TCP master when TRB245 acted as a slave. We could not reproduce the issue using this application.

Then we used windows PC with a COM test pro application and we were able to reproduce your issue. But once we set the timeout value to 5 seconds in the TRB245 slave configuration page, it worked like a charm once again. 

Please try setting the timeout value and check.

Best regards.

by
Okay, I'll try with timeout value settings.