Sawtooth Peak Detection

[BigbenGrundy]

Hello Everyone:
I have a machine in the field with a twin diaphragm pump driven by a VFD. It Produces a "sinusoidal sort of" process pressure waveform.



We need a process pressure value to control the speed of the pump.



How would you write a program in RS5000 to capture (a trend) the peaks of this waveform?

Any help would be greatly appreciated.

Thank you in advance.

 

[BigbenGrundy]

So far

This is what I have so far
The issue I am having is the amplitude can be so great that the peak drops down when it shouldn't. so now I am trying to figure out how to approach this the best way

 

[gclshortt]

http://www.plctalk.net/qanda/showthread.php?t=94539

The above thread may help you out.
Regards,

 

[BigbenGrundy]

GCLshortt

Thats helpful but I need to be recording the peaks more than a average of it all.
Any advice?

 

[Peter Nachtwey]

Use a max function to capture the positive peaks and a min() to capture the negative peaks.

 

[BigbenGrundy]

We ended up determining formula allowed us to say that at a certain hertz we needed so much time to see 2 peaks and used that to help us pull our values.
The biggest problem that I had before was trying to determine when to reset our values to find new ones. That is why we got rid of the old method and created this new one.
Less work easier to manage.

 

[BigbenGrundy]

Thank you all for your help
I Greatly appreciate it