command an inverter with NI9262

[M.ezzakkar]

Hi guys,

I would like to command a motor speed with an inverter. I decided to use an NI9262 voltage output in labview 19. I'm loading an excel table with two raws one for time and one for the voltage which will match the desired frequency on the inverter. I would like to know how i can provide the output voltage at the desired time. Anyone has a clue ??

[RavensFan]

First, get the file open, read, and close out of the loop.  You don't need to do that each and every loop iteration.  Just feed the 2-D array data into the loop.

Then just index the data row by row, waiting for the amount of time in the first column, and feeding the analog value from the 2nd column to your DAQ device.

What amount of time are you dealing with between each step?  Fractions of a second?  Multiple seconds or minutes?  Is the timing consistent?

The answers to those questions could affect the way you want to write the data to the DAQ device.

[M.ezzakkar]

we are working on a bench which will work for 200 houres for data aqcuisition so it's a very big amount of time

[RavensFan]

Okay.  So writing one value at a time will work.

With long times between samples, you will want to iterate the loop fairly frequently so the program is responsive in case you need to stop it mid run.  Let's say every second.  Then you will compare the current time with the time in the first column and when the time is passed, then you send the new value and update your target time to the next value in the array.

[M.ezzakkar]

hi again,

Thanks a lot for these tips. Can you provide something i can start with thaough labview is all new for me!! Thanks

[RavensFan]

I see you have a stand alone array constant in there.  When I enlarged it so I could see the data, column 0 went from 0 to 2.8 in 10 steps.  And column 1, went from 0 to 81.1 in steps of 5 followed by .1.

Are those you times and voltages?  2.8 seconds?  81.1 Volts?  (That would be too large.)

[M.ezzakkar]

it's just a test row i haven't scaled the voltage yet the second row will take values from 0 to 10 in fact.

[RavensFan]

This probably needs some adjustments to the code, but it should give you an idea of what you can do.

[M.ezzakkar]

Thanks a lot man much regards