Time delay in matlab fuction block used in simulink model.

Hi, I developed a power system in simulink. Here, i also use matlab function block and some coding in it. Now i want that when simulink power system starts to simulate, then matlab function block do not operate for first 2 seconds of simulation. In other words i want 2 second time delay of matlab function block. How can i perform that?

Thanks

Answer 1

[Jim Riggs]

Place your Matlab function block into a triggered subsystem block (or an enabled subsystem block), then trigger/enable the block based on time.

[Muhammad Mazhar Saeed Butt]

Thanks for answering.

But actually i want to do is that, function block give 1 output to circuit breaker till 2 seconds of simulation and after 2 seconds then it should follow this code.

 function y = fcn(A)
if A >= 1.8200e+06
    y=0
else y=1

end

[Muhammad Mazhar Saeed Butt]

Kindly suggest changes in coding for that

[Jim Riggs]

This is simply selecting between two constant values based on a logical condition. This network performs this task. The logical compares A with 1.8200e+6. When true, it enables the upper subsystem block, which simply outputs the constant 0. When the logic is false, the lower block is enabled, which simply outputs a constant value 1. The merge block us used to combine the outputs of two or more enabled blocks, where only one is enabled at a time.

[Muhammad Mazhar Saeed Butt]

Thank you so much.

[Jim Riggs]

After looking at your post again, I think that maybe this is what you want; Do something for the first two seconds, then output 0 or 1 based on the value of A. In this case, the top-most enabled block is run for the first two seconds, then the lower network is enabled and outputs a value based on the value of A.

[Muhammad Mazhar Saeed Butt]

Yes this is exactly i want. The y should be equal to 1 till first 2 seconds of simulations and after 2 seconds the value of y should base on value of A. Can you suggest changes in code for that?

 function y = fcn(A)
if A >= 1.8200e+06
    y=0
else y=1
end

[Muhammad Mazhar Saeed Butt]

[Jim Riggs]

This is what the last network does. The top enabled subsystem should output a value of 1. This network outputs 1 for the first two seconds, and then either 0 or 1 based on the value of A.

[Muhammad Mazhar Saeed Butt]

It really help me. Thanks for your help

[Jim Riggs]

 function y = fcn(A,time)
if(time <=  2.0)
    y=1;
else
   if (A >= 1.8200e+06)
       y=0;
   else 
       y=1;
   end
end

[Muhammad Mazhar Saeed Butt]

It solved my problem. Thanks again.