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From: Praetorian <ashish.sadanandan@gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: C2000 DSP and Simulink : using a memory-stored variable as a 
Date: Thu, 6 Mar 2008 08:06:51 -0800 (PST)
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On Mar 6, 7:08 am, "Kevin " <kedec...@mathworks.com> wrote:
> Thank you very much! You're being very helpful
>
> But just for further developpements, is it possible to
> dynamically change block parameters on the DSP without
> creating custom blocks?
>
> "Antonin Ancelle" <antonin.ance...@mathworks.com> wrote in
> message <fqoqve$49...@fred.mathworks.com>...> Hi Kevin,
>
> > I am going to send you a direct email with a burst model
> of a PI controller
> > where you can dynamically change the parameters.
> > It has no D component, but you can easily add it if you
> have a need for it.
> > It is more conventional than the TI version in the sense
> that the P
> > component is not cascaded with the I.
>
> > On the TI version if you put P = 0, the rest will be 0
>
> regardless of what I
>
> > or D component you have.
>
> > I will let you play with it.
>
> > Good luck,
>
> > Antonin.
>
> > "Kevin " <kedec...@mathworks.com> wrote in message
> >news:fqogav$eol$1@fred.mathworks.com...
> > > Hello,
>
> > > I've been toying with the C2000 toolbox for a little while
> > > now, but I'm hitting a wall on this one.
>
> > > What I'm trying to do is a PID controler whose parameters
> > > can be changed by an external source or using a RTDX
> channel.
> > > In fact this problem might arise for every block whose
> > > parameters can't be specified from the outside.
>
> > > Now I could create the controler with basic Simulink blocks,
> > > but I want to use to more efficient PID-Controler from the
> > > DMC library.
>
> > > Since the C2000 doesn't have a workspace, I tried to use the
> > > "Memory Copy" block from the Link for Code Composer Library
> > > with no results since the parameters must come from the
> > > workspace.
>
> > > Is there a way to tell the block the the value of a
> > > parameters must be taken from memory and not from the
> workspace?

Hi Kevin,
There is no direct way to do that. But in case of the TI C2000 library
PID controller the workaround is quite simple since the block diagram
of the PID is given on the help page for that block. Just use blocks
from the IQmath library to re-create the PID, except you'd have input
ports for all the parameters you want to change, and then From Memory
blocks feeding those inputs.

HTH,
Ashish.