Process Automation and Recipe Creation Advice Needed

[Srutan]

Hi all,

I'm new user of LabVIEW working on a process automation project.

The process involves a syringe pump, two temperature controllers, and an 8 channel Mass Flow Controller (with 6 process gases and a Mass Flow Meter attached).  All of these devices are connected via RS-232 -->USB and need to be controlled by LabVIEW.

I've created a VI that allows for manual control over these devices from a single screen, but am not sure how to proceed from here to an automation scheme.  I'd like for the user to be able to create and run recipes (with the option of loading previous recipes or saving current ones).  

My current idea for each step in the recipe goes a little like this:

1) User selects device to be altered in the current step

2) User selects desired parameter change (temperature setpoint, flow rate, etc)

3) User selects condition on which step occurs (time delay, temperature reaches a specific value, etc)

4) User adds step to recipe sequence 

I've read several other posts here about recipe creation using string tables, but have yet to see a working version's block diagram.

I'm not sure how I should control each device (subVIs, states, whatever), or how to use a table to set a sequence of events in motion.

Please help!

Thank you.

-Shawn 

[Jared_B]

Hey Shawn,

I'd definitely recommend a state machine for this behavior.  Here is an example that might help you get up and running.  The file is missing the typedef for the steps, but you should be able to use this as one idea for how you could base this.  Essentially you could have the File IO aspect be a list of 'steps' that are saved (in array form) by your user.  If there are specific parameters that go along with them, you could figure out how to include this information in the file as well.  This method is pretty slick, and is nice an expandable.  The only tricky part would be to handle the additional data changes for the temperature setpoint and flow rate, etc).  You could possibly do this with a 2D array and have the first dimension be the step, and the second dimension be the values, etc.  Just an idea.

Message Edited by Jared_B on 05-04-2010 05:35 PM

[Srutan]

Thanks Jared!

Very helpful advice.

I used a state machine to take care of the automation sequence and a table for the recipe information (each column holds a different process parameter, rows are steps) with the ability to add steps and save/load recipes to/from spreadsheet files.

Thanks again for responding.

[Jared_B]

Hey Shawn,

My pleasure!  If you come up with a good architecture for what you're doing.  Feel free to submit a minimized version of it to the NI Developer Zone Community and share with others!  Hope you have a great rest of your week.

[pravee]

Hi to all
 

Thanks Jared!

Very helpful advice.

I used a state machine to take care of the automation sequence...................................

----------------------------------------------------------------------------------------

www.plctraininginchennai.com

www.plcscadatraining.net

[pravee]

Thanks Jared!

Very helpful advice.

I used a state machine to take care of the automation sequence...................................

----------------------------------------------------------------------------------------

www.plctraininginchennai.com

www.plcscadatraining.net