determine whether a input port is connected or not to a block

Hi

I need to realize a Simulink block, which is capable to determine whether a input port is connected or not to a block if it is not connected ( which means, I guess, the input is null or empty) it returns 0 and it change the color of the port, otherwise it forwards the input to the output pourt.

I thought to use a matlab Fcn to realize this function I found helpful these commands portData = get_param(gcb,'PortConnectivity'); portData.SrcBlock

But it doesn't work as I want

Do you know if there is any way to archieve that? Any advices are welcome

thanks in advance

[grapevine]

Sorry I said something wrong I cannot use a Matlab fcn but only an Embedded Matlab fcn, because my prof-boss doesn't wanna no mfiles in the library

If it was possible to use the Matlab fcn I would write that

if exist('u')

y = u;

else

y=1

end

but I can't

little help?

Answer 1

[grapevine]

I found it! I wrote this code in a callback function

portData=get_param(gcb,'PortConnectivity');
if (portData(1).SrcBlock==-1)
set_param(gcb,'Intern_External','0')
else
set_param(gcb,'Intern_External','1')
end
clear PortData
and it works

[Jorge Castillo]

great