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I'm working on a project to connect and interact with a cell of machines (8 PLC aprox) with datasocket, the app consist in a simple communication to poll a trigger, read and search the partnumber and retrieve data to PLC from a SQL database. I use QMH to start this project, and I made a MHL with the functionality of ONE machine (PLC and SQL communication, and a few messages to UI loop).

This loop I called "Station Handler" is initialized with a configuration file which haves unique information to run each machine (CSV file with tags and parameters of SQL), I convert this loop in a SubVI and configured to be < Preallocated Clone Reentrant >, and I configure the datasocket subvis that i made to be reentrant also.

When I run the application it works fine with the PLC about a couple of cycles (write/read), also I can use the two PLC I currently have to do tests, but suddenly, the "Station Handler" vi dont read ok the trigger tag, i have it in true and labview never read it. Is not a problem of network or OPC because I already open a OPC test client and read ok the value of the trigger tag.

I will appreciate if anyone can help me... and sorry for the english if I dont explain myself enough haha

Also I'm open if there is a better way to achieve this, and QMH maybe wasn't the answer...


Top level VI



Station Handler loop in Poll trigger state



Poll trigger VI




Thanks in advance!



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