02-24-2014 05:18 AM
Hi,
I have a PXI-6259 card and am using Labview.
I need some advice on the best method of achieving the following requirements:
Drive four pneumatic valve units, each has four solenoid valves. two to apply air and two to vent air.
There are 2 apply profiles and two vent profile - this is for an extended life test
So for one unit the sequence is:
I am ok with the above and have put together some rudimentary VIs to load a profile then drive a DIO pin and sample the output - I've attached these.
I would implement the above using a state machine.
I have the interfacing hardware from a previous project
The reason I require some help is that we would like to run four units in parallel with different profile and with offset start times and I am in need of some advice about achieving this
Thanks for any guidance that can be offered.
Dave
02-27-2014 04:32 AM
Hi Dave,
What do you mean by offset start times? Are you setting a single test to run and then automatically want the other tests to run after that or are you setting this application to run at a specific time then walking away and leaving it to its own devices.
It sounds like you need a central controller which is scheduling when the tests need to run and then running them as needed, similar to a queued state machine where you set each of the four units into an idle state, and then send instructions by a queue from a "Master" controller loop to run the tests as needed. It looks like in terms of getting started you have all of the DAQ code you need, now I believe it is more on the architecture side of things.
There is a good article on our website covering the queued state machine, and goes through some the basics and a high level overview of the architecture:
https://decibel.ni.com/content/docs/DOC-32964
Let me know what you think of this and if you have any questions feel free to reply.
Best Regards,
James Kent
05-21-2014 03:04 AM
Hi James,
Thanks for your reply; I am back on this project now following some delays.
I am struggling with the queued state machine archeture and could use some further guidance please.
Here is a more concise list of requirements:
I have attached a spreadsheet overview of the profile which shows a single shot.
Thanks for any advice you can offer.
Dave