Square Waveform Control

[BLW]

Please see attachement.  I have recently taken over a project for which the previous developer is no longer around.  I have virtually no experience with LabView before being introduced to this project.  I have read "LabView for Everyone" and feel comfortable with the basics of programming. 

The existing VI uses a waveform to generate voltage to operate a set of mass flow controllers.  My problem is that I cannot open and manipulate the waveform.  I have improved the hardware on this sytem and therefore need to manipulate these waveforms to fit the improved system.

Does anyone know how to open or manipulate the attached document?  I presume this is a file that has been converted to a readable/executable only file for LabView to utilize in the VI.  I have searched the rest of the computer for the original file to no avail....

If you can't help with the attached file could you please direct me to documents that would teach me how to build such a waveform controller?

Thank you,

Bradley

[smercurio_fc]

That appears to be a datalog file. The functions to read/write these files are in the File I/O -> Advanced File Functions -> Datalog palette. However, in order to read them you need to know the structure of the record that was used to write the datalog file. Since you have the code, somewhere in the code there should be a datalog open file function that has a record structure wired to it. You need to wire this same type in order to open the file. Examples ship with LabVIEW to show you how to read/write datalog files.

Message Edited by smercurio_fc on 07-06-2009 12:53 PM

[BLW]

Thanks for your reply.  I am able to use the current file and read it into the code.  However, I would like to maniuplate the shape of this waveform and havn't found the way to do this.  Maybe I am not understanding your post so I have attahcehed a screen shot of part of my code.  If you could tell how I open and manipulate the shape of this waveform or maybe you can lead me to documents that will help to build a new waveform for the same purpose.  I've spent the last week searching for such documents but to no avail.

Thanks again...

[smercurio_fc · Accepted solution]

When you said you cannot open and manipulate the waveform I took that to mean you couldn't read the file. Based on what you're saying now you can open the file to read the waveform. You just need to change the waveform. Two different things.

What do you need to do to the waveform? Or, what kind of waveform are you trying to create? There's lots of functions in the Signal Processing palette, and with simple manipulation, like scaling, you can also just use the arithmetic functions.

[BLW]

Thank you.  I needed a little poking and proding to keep me headed in the right direction.  Problem is resolved.

BLW