Looking to create DO pulse on demand with 9375 Module in 9178 backplane

[PChemist]

Hey Everyone,

I am trying to create DO pulse using a 9375 module in a 9178 backpplane. The pulses are being used to control relays in other equipment. I used to do this with DO but I've never worked with the DAQmx before. I've been looking through the help and resources and they all point to the assistant. I've tried that and can't seem to make it work. I can set the bits high and low in MAX so I know everything is hooked up.

Any help would be great!

[PChemist]

Update:

I've kept plugging away at the help and examples and I came across one that gets me halfway to my goal. I've attached it below.

I have tried editing it to extend the time of the "ON" pulse and can't get it to increase. If anyone has a hint as to how to make pulse stay on for a user selectable time that would be great.

Thank you.

[DigDoug]

The timing settings in the front panel of your VI controls the loop iteration time of your while loop not the duty cycle of your signal. You should be able to change the number of bits to write at any time while the application is running. A case structure would likely be the best method for making the pulse stay on for a time that is selectable by the user.

Best,

Doug

[PChemist]

Thank you for the reply. I was able to get a version up and running but now I have other users who need to use my tool. I would like to improve the VI to make it easier for them. Do you have a basic example of what you described? Is it possible to write a string to the port on the 9375 that will set it "on" until a string is written to turn it "off"?

Thank you!

[DigDoug]

I'm not sure exactly what you are trying to do within the case structure, but here is a link to the LabVIEW Help for case structures. This link explains case structures pretty well and links to other pages that give other tips and tricks related to programming with case structures. 

You can implement some logic to compare the string input by the user to a string constant. If they match, then a true is sent to the case structure and you can put in your code to write a digital high to your module in the true case. An enum might work better than a string command from the user, then you can have the user select between on, off, and default states. Check out the Case Structure example by browsing to help > find examples > fundamenals > loops and structures > Case Structure - Selector Data Types for a simple case structure example