Issue: LabView freezes after 30 min of execution when acquiring data from thermocontroller

[Romangr]

Hi everyone.

I've made a VI in LabView to acquire data from a temperature controller.

The code is very simple and just includes a "DataSocket Open" function which establishes a connection to the instrument (using URL), then "DataSocket Read" function put in a while loop for data acquisition every 1 sec with plotting collected data points on a chart diagram. This program works fine for first 30 min but right after that LabView just freezes and not responds anymore. It's possible to close LabView by only the Task Manager (Windows).
I used "Profile Performance and Memory" tool in LabView to check memory leaks. But it showed that the VI uses extremally small amount of memory (about 100 kB) which slightly increases during the execution.

What could be the problem? How can I fix the program freezing after 30 minutes of work?

LabView version: 2015.

Instrument: 3504 Temperature Controller by Eurotherm company.

Connection: USB.

The VI is attached.

Thank you for any suggestions.

[Andrey_Dmitriev]

It could be an issue with particular OPC Server and now with datasocket.

I would like to recommend to check if you have same issue with NI Server, for example, connect to

opc://localhost/National Instruments.NIOPCServers.V5/Simulation Examples.Functions.Sine1

I've used DS in such form many times and haven't seen such issues so far (not from LabVIEW side).

In given example you will collect your data in for loop (on indexed output), but if you run it 30 min only with once per second - it is only 1800 DBL readings, is it nothing critical, should not lead to freezing anyway.

[SimonAldred]

I have a similar issue when writing to a PLC via datasocket. This problem has plagued me for months. I am using a different OPC server for this application - one that works for Siemens PLCs. I normally use RS Linx classic for Rockwell PLCs without any issues. Anyway the freezing seems to occur randomly and appears to affect the .exe software more than the source code. Tests are still ongoing. 

Regards

Simon