How to get rid of "Error: The value of non-tunable property 'Index' does not match" when trying to choose a particular gold sequence using MATLAB function in Simulink?

I am designing a system where I can flexibly choose a gold sequence using switch statement based on an index value. I am implementing this in Simulink using MATLAB function. The code I implemented is as follows:

switch PN_selector

case 0

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',-2,'SamplesPerFrame',31);

case 1

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',-1,'SamplesPerFrame',31);

case 2

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',0,'SamplesPerFrame',31);

case 3

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',1,'SamplesPerFrame',31);

case 4

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',2,'SamplesPerFrame',31);

case 5

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',3,'SamplesPerFrame',31);

case 6

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',4,'SamplesPerFrame',31);

case 7

goldseq = comm.GoldSequence('FirstPolynomial',[5 2 0], ...

'SecondPolynomial',[5 4 3 2 0], ...

'FirstInitialConditions',[0 0 0 0 1], ...

'SecondInitialConditions',[0 0 0 0 1], ...

'Index',5,'SamplesPerFrame',31);

otherwise

msg='Incorrect PNSelector received.';

error(msg);

end

As soon as I trz to run the program, I get the error The value of non-tunable property 'Index' does not match. What am I doing wrong here?

Answer 1

[Pratyush Swain]

Hi Prashanth,

I understand you are designing a system which uses a switch statement and you are using a matlab function block. Assuming 'PN_selector' as an input to the block,you are trying to set a block parameter during run-time.

Please refer to https://www.mathworks.com/matlabcentral/answers/776747-change-simulink-block-parameter-during-simulation article which explains the updation of parameter of an simulink block during runtime.

Hope this helps.