Hi Mike, The error occurs because for code generation in Simulink, you have to define the array 'y' before indexing or sub-scripting it as 'y(n)'. The same function works in MATLAB but not in Simulink. So you would have to pre-define the array y using the zeros function as per the length of the data you are using.
Could you specify the exact nature of the output that you desire? As per the circuit above, it seems to me that the variable m will be passed on to the output as it is. In such a case, there is no need for the above function block. In case you wish to obtain a shifted version of 'm', you can use the delay block instead.
Cheers
