Thread Subject: RTWT: soft real time or hard real time?

Hello,
I have a 12th order plant which I am trying to run in real time at sampling of .0001 secs. I have tried both real time windows target and xPC target to run plant in real time.

In RTWT my plant runs slower than real time while in xPC it runs properly. Though in xPC if I add data logging capabilities with my plant I some times get CPU overload error and simulation stops. I am assuming this happens because execution cannot be completed in real time.

So my question is why does not RTWT stop when my model runs slower than real time? Is it because RTWT implements soft real time constraints and xPC implements hard real time constraints? I am using same PC for running both RTWT and xPC target.

Thanks
Trupti

Hi Trupti,

Please refer to this link which contains information on the differences between RTWT and xPC Target.

http://www.mathworks.com/support/solutions/en/data/1-AYQQZ5/index.html

Anish Anthony
MathWorks Inc.

"Trupti Ranka" <trupti_ranka@yahoo.com> wrote in message <hdgb31$ma6$1@fred.mathworks.com>...
> Hello,
> I have a 12th order plant which I am trying to run in real time at sampling of .0001 secs. I have tried both real time windows target and xPC target to run plant in real time.
>
> In RTWT my plant runs slower than real time while in xPC it runs properly. Though in xPC if I add data logging capabilities with my plant I some times get CPU overload error and simulation stops. I am assuming this happens because execution cannot be completed in real time.
>
> So my question is why does not RTWT stop when my model runs slower than real time? Is it because RTWT implements soft real time constraints and xPC implements hard real time constraints? I am using same PC for running both RTWT and xPC target.
>
> Thanks
> Trupti

Hello Anish,
Thank your very much for the link.
Trupti

Anish Anthony" <anish.anthony@REMOVETHISmathworks.com> wrote in message <hdjr9n$b9s$1@fred.mathworks.com>...
> Hi Trupti,
>
> Please refer to this link which contains information on the differences between RTWT and xPC Target.
>
> http://www.mathworks.com/support/solutions/en/data/1-AYQQZ5/index.html
>
> Anish Anthony
> MathWorks Inc.
>
> "Trupti Ranka" <trupti_ranka@yahoo.com> wrote in message <hdgb31$ma6$1@fred.mathworks.com>...
> > Hello,
> > I have a 12th order plant which I am trying to run in real time at sampling of .0001 secs. I have tried both real time windows target and xPC target to run plant in real time.
> >
> > In RTWT my plant runs slower than real time while in xPC it runs properly. Though in xPC if I add data logging capabilities with my plant I some times get CPU overload error and simulation stops. I am assuming this happens because execution cannot be completed in real time.
> >
> > So my question is why does not RTWT stop when my model runs slower than real time? Is it because RTWT implements soft real time constraints and xPC implements hard real time constraints? I am using same PC for running both RTWT and xPC target.
> >
> > Thanks
> > Trupti

Hi Trupti,

I would be interested to see a model that runs slower than real time in
Real-Time Windows Target. To my knowledge, this should never happen. How
much slower does your model run? How do you measure the run time of the
model?

Thanks, Jan


Trupti Ranka wrote:
> Hello Anish,
> Thank your very much for the link.
> Trupti
>
> Anish Anthony" <anish.anthony@REMOVETHISmathworks.com> wrote in message <hdjr9n$b9s$1@fred.mathworks.com>...
>> Hi Trupti,
>>
>> Please refer to this link which contains information on the differences between RTWT and xPC Target.
>>
>> http://www.mathworks.com/support/solutions/en/data/1-AYQQZ5/index.html
>>
>> Anish Anthony
>> MathWorks Inc.
>>
>> "Trupti Ranka" <trupti_ranka@yahoo.com> wrote in message <hdgb31$ma6$1@fred.mathworks.com>...
>>> Hello,
>>> I have a 12th order plant which I am trying to run in real time at sampling of .0001 secs. I have tried both real time windows target and xPC target to run plant in real time.
>>>
>>> In RTWT my plant runs slower than real time while in xPC it runs properly. Though in xPC if I add data logging capabilities with my plant I some times get CPU overload error and simulation stops. I am assuming this happens because execution cannot be completed in real time.
>>>
>>> So my question is why does not RTWT stop when my model runs slower than real time? Is it because RTWT implements soft real time constraints and xPC implements hard real time constraints? I am using same PC for running both RTWT and xPC target.
>>>
>>> Thanks
>>> Trupti


--

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Jan Houska HUMUSOFT s.r.o.
houska@humusoft.com Pobrezni 20
http://www.humusoft.com 186 00 Praha 8
tel: ++ 420 284 011 730 Czech Republic
fax: ++ 420 284 011 740