Hello Everyone, I have finally come to a problem in labview that is over my head. Until now I have been making small programs using MC DAQ-USB 1208 or USB 1608 to run my programs and have gotten pretty good at reading block diagrams but still struggle with making them. I am looking to control a series of solenoid valves of a proportional valve to dispense two liquids to create a linear gradient. For those of you not familiar with how a proportional valve works, if you programmed it to deliver 75% of A-solvent and 25% of B-solvent, the valves would open A-B-A-B-A-B… in a 75:25 ratio of opening times. To deliver a gradient like i am wanting, the ratio of the opening times of the various proportioning valves will change during the gradient to change the overall concentration. I have done all the math which i have attached below and have included a setup of my system as well. There will be two pumps, each with a different flow rate. One pump, P2 will be used to pull the gradient from the proportional valve into a loop of known volume. once the loop is filled, a 6 port 2-way valve will be switched and using the second pump, P2, the liquid will be pushed though the outlet. Below I think i have included everything that will be on the project window. There will be a series of steps with each step having time and %B as inputs (we can ignore pump flow rate because it will be a constant). Those inputs translate to the picture below to generate the slope. There are also a series of constants listed to the right that will not change throughout gradient formation. The equations of the program are listed at the bottom and if someone could assist me in getting this program off the ground that would be amazing. Any questions or clarifications I would be glad to make and any assistance would greatly be appreciated. And I am runing LV2013 64-bit.

LabVIEW

lynchkb

As nathand statedm, depending on your application ifyou are seeing that some data is missing, you can use queues to avoid this situation!

"everything is achieveable through technology'

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