Error using Merge Block

Assalamualaikmum & Hi all

I have a problem that is matlab error report like this "output port 1 is required to be persistent, hence this signal cannot be connected to a Merge block."

anyone can help me

[Fangjun Jiang]

The output of what block are you connecting to a Merge block?

[Mohd Hazny Aziz]

Continous Sigmoid block. It from WinCon toolbox

Answer 1

[Mohd Hazny Aziz]

Thanks for help my problem already fix. Its actually a bug when using matlab 2007b. I found the solution on this link http://www.mathworks.com/support/bugreports/528501

Answer 2

[Fangjun Jiang]

I don 't have that Toolbox so can't comment the specific. But simply said, you can not connect the output of that block to the Merge block. Double click the Merge block and click the "help" button, there is explanation about the Merge block. There are other situations that the output of certain blocks can not be connected to the Merge block.

[Mohd Hazny Aziz]

ok. thanks for answering my question. However what does matlab mean by "is required to be persistent". Do you have any idea?

[Fangjun Jiang]

I know "persistent" from MATLAB M-programming point of view but never heard it is required by Simulink. Inside an M-function, you could define a variable temp, which is not an input argument nor an output argument. When the function is completed, the variable temp is going to be cleared. But if temp is declared as "persistent", it is not going to be cleared. Instead, it is saved, and the next time the same function is called, the variable temp can be used starting from its previous value.

Type help persistent or doc persistent for more information.