How to construct a program with a Linear Ramp that reaches and holds a constant value in LabView 6.0

[samito]

I am new to LabView and I am currently working with LabView 6.0.  I have not found much on how to create a program that contains a linear ramp function.  I am trying to create a program that will control a drive motor with a 5 minute ramp up time from 1000 rpm to 11,500 rpm and then hold at the 11,500 rpm for 100 hours.  Anyone have any input on this?

[adigator]

Hi,

Here is some advice:

1. Since your new to LabVIEW I strongly recommend you to spend some time on the basic principles. This is a good start.

http://www.ni.com/gettingstarted/labviewbasics/

2. Search the LabVIEW in built examples for good starting points for your problem:

Help/Find Examples...

3. There is a "Ramp Pattern VI" in newer LV Versions, don't know if this exists in LV 6.0..

http://zone.ni.com/reference/en-XX/help/371361E-01/lvanls/ramp_pattern/

4. Search the forum for similar questions:

for example: http://forums.ni.com/t5/LabVIEW/ramp-generate/m-p/2052198

5. Search NI.com for tutorials and information about your problem:

for example:

motion control: http://www.ni.com/white-paper/11630/en

timing: http://www.ni.com/white-paper/11466/en

Hope this helps to get you started!

regards,

adigator

[samito]

Hi Adigator,

Thanks for responding to my post.  I have had some time to go through all of the general portions of LabView as well as some of the other sections that you suggested.  Unfortunately, my LabView version 6.0 does not support the "Ramp Pattern VI", that would be so much easier if it did.  I did not really see anything that was exactly what I was looking for but there are a few examples that I do what to experiment with.  Currently I have a program that almost works as needed.  I wrote a ramp function which seems to be working fine.  The only problem I am having is that it will not ramp for 5 minutes, at 167 seconds it restarts the counter at 0 and continues to ramp at its current motor speed but starts the timer over.  If I change it to 150 seconds from 5 minutes, it will change to the constant speed for its time segment as its supposed to.  Also, how can I get the 'Time 2' segment to run longer (100 hours)?  If I put that value in in seconds its too large.

Anyhow, I just need my program to have a linear ramp that operates a motor from 2000 rpm to 11,600 rpm over a 5 minutes and then hold it at 11,600 rpm for 100 hours.  Should be pretty simple but I can't get the bugs worked out.

Attached is my current program, could you take a look at it and let me know what I might be missing?

Thanks in advance!

[samito]

I figured out that the Count Events or Time counter that I'm using is overflowing after 167 seconds.  Is there a way to change that or is there a different/better counter I should be using?

[adigator]

Hi,

These are the links to the timing functions I use the most:

http://zone.ni.com/reference/en-XX/help/371361H-01/glang/get_date_time_in_seconds/

http://zone.ni.com/reference/en-XX/help/371361H-01/glang/tick_count_ms/

But I have no clue, if these are available in LV6.0..

regards,

adigator