Ramp up, Hold, Ramp Down

[LDA]

Perfect...

Thanks for the help.  I'm gonna study this for a bit and try and figure everything out.  Know a spot for some good tutorials?  I'm making my way through the Basics 1 course manual but I'd like to bang through some more examples.

[aeastet]

The examples that NI has for Labview are the best help I found when I was starting out. I also had a couple of books that explained what everything was. Once you know what all of the parts are it is much easier to put them all together.

Have you ever programmed before?

[aeastet]

You can also Look here for more info.

http://zone.ni.com/dzhp/app/main

[LDA]

Nope, I'm a SolidWorks guy that got thrown into Labview.  I like it.  A bit confusing at first because there are SO many ways to do things, overwhelmed right now but again it's only my second week.  Give me a couple months and hopefully things will get much easier!

Either way thanks for the support 

[LDA]

Aeastet,

I've been going through what you've sent to see what I did and didn't grasp. 

Going through the boolean values of the shift register on the while loop and the boolean values on the inner case structure...  My understanding is that the value on the while loop starts true and remains true until the "hold" of the true conditional loop.  After the hold, false is output to the while loop starting the decrement.  If false was never output to the while loop the value would remain true and continue to increment, "hold", increment, infinitly...  Am I on the right track?

[aeastet]

Yes that is true. If you never reach the set point or you did not have the false in the case structure where the hold is then the system would just cuntinue to incriment up until stopped.

[053647967]

Hello Mr. Tim

I looked at your program and i have a few questions:

-how can i change it into a voltage ramp?

-could this be improved into a ramp that goes uo,holds,  then again goes up,holds, goes a liitle down,holds, agains goes up...as i like to set inputs?

[aeastet]

If you know what you want to do then I would make an array that generates a signal to an analog output. Feed that array into a loop so that it update the analog output everyiteration. Have the loop timed so that you get the ramp rate that you want. It would be fairly easy to do.

[Mystogan]

Hi Tim,

I've looked at your program and I want to ask you:

Using this structure, can you change the speed of ramp down (to have it different from ramp up)?

ex:

ramp up = 5 seconds,

hold = 5 seconds,

ramp down= 10seconds.

Regards,

Yan.

[J-Barticus]

Hi Yan,

I took a look at Tim's code and with a few additions to his VI you can include a ramp down time different than the ramp up time. Basically it comes down to changing the timing of the while loop such that it coincides with whichever timing case you are in (ramp up, ramp down). There may be multiple ways to accomplish this, I did it by creating a seperate set of case structures whose case selection corressponds to that of the orginal case structure, inside these case structures were the required timing information to route to the Wait VI. Also I included a sequence structure around the current indicator because of a race condition that was occuring when exiting the hold or "Burn Time" setup.

Attached the edited file.

Best,

Jake B.