Controlling Valves with a Producer/Consumer structure

[gmartinez]

Hi all,

 I 've been working in a research where temperature and pressure can cause serious material failure. I've made a sequence in a text file of 0's and 1's with a time column in it. I've been using a program where labview reads this text file and starts controlling the valves by itself. The problem now is to add a maximum temperature or pressure value for the labview program to run an "emergency sequence" if the measurement exceeds this limit. I've been trying to use this program with a DAQ Assistant in a while loop but I've been having problems with it.

Someone suggested me that I should use a Producer/Consumer architecture to do this, but the problem is that I've been working with LabVIEW for 2 months, so I am not an expert. I wanted to see if anyone could help me build this program with such architecture.

[DylanC]

Hi gmartinez,

Here is a great example of using a producer consumer architecture while acquiring data.

https://decibel.ni.com/content/docs/DOC-2431

You will want to model your VI after this except instead of writing the data to a file in the consumer loop, you will want to check if the data is out of range and then execute your 'emergency' code sequence. A case structure inside the consumer loop would be a great way of achieving this. If you want to see the design pattern you can also go to

 File->New....->VI->From Template->Framework->Design Patterns->Producer/Consumer Design Pattern(Data) 

in LabVIEW.

Regards,

DylanC

Applications Engineer

National Instruments

[gmartinez]

Hi Dylan,

I was trying to open the vi in my LabVIEW 2009 and it said that the file is not a resource file and that it couldn't be loaded. Any suggestions? 

Gus

[gmartinez]

Hi Dylan, 

I got the program running but had some trouble with it, so I modified my other program but now the problem is that the DAQ Assistant reads just one sample and stops reading them continuously. I wanted the DAQ Assistant to continue reading but I am not sure how to do that. Any suggestions?

Attached is my program.