CLX EIP Driver No Response From PLC and unknown code 38

[mondacag]

Our customer is experiencing some issues with the application we devoloped. For the nature of the error messages i suspect is some kind of interweaving.

We are using v3.99w

There is only one drive to communicate with a compactlogix, the PollRateOverride was set to 500, just changed to 2000 as recomended in another thread (https://advancedhmi.com/forum/index.php?topic=1763.0)

The error shows sometimes when trying to read an UDT of 1244 bytes. Some times it shows the "No Response From PLC" message, and other times it shows an error message "index and length must refer to a location in the string", i think it is related with the code to extract the data from the UDT.

While connected over teamviewer i saw the message "read failed. unknown code 38, status code=38", but i wasn't able to reproduce.

There are 9 BasicLabels being used with the ValueChanged event to do different actions like read and write individual tags from/to the PLC.

This used to happen once in a while, the customer used to solve this by restarting the application, but it started to happen too often since yesterday. They noticed the machine time cycle increased. And while monitoring, i noticed that some times it takes too much time to execute one of the events. Maybe because the program is doing something else.

I'm considering to add a second driver for readyng the data only.

Any suggestion are welcome

[Archie]

The first thing I am going to recommend is to upgrade to 3.99x, then possibly trying to increase the Timeout property.

[mondacag]

Thanks for your responce Archie.

It's almost two weeks since we implemented your recomendations, we haven't received any complains about this issue.
I fortgot to mention that due to our customer requeriments we are using VS2010.

[bachphi]

I was wondering if the system is XP? and if you just upgraded version only? timeout ?

[mondacag]

Windows 7 Professional, upgraded from 3.99w to 3.99x and set the timeout to 5000 instead of the default 4000.
Haven't checked if there have been any system updates (OS, .NET Frameworks, etc) since our customer's IT department is the responsible for that.