How to set Parameters of Block "custcode/System Outputs"

How can I set the Code for the block "custcode/System Outputs" programmatically? I receive an error "Size arguments must be real integers" when opening the block by double-click after running the following:

add_block('custcode/System Outputs','model/subsystem')
field = setfield(get_param('model/subsystem/systemOutput','RTWData'),'Top','test');
set_param('Copy_of_model_vergleich_atom/Subsystem1/test','RTWData',field);

[Anish Mitra]

Would it be possible to share a sample model and code? Implementing the above commands on a basic 'Outport' block in Simulink (R2015b) does not throw the error.

[Steffen Müller]

But that's what throws the error for me. I'm not using a "basic" output port, but "System Output" block from custcode-library.

Answer 1

[Steffen Müller]

I found myself a solution: Adding a newline after the desired function call of the field (for whatever reason):

add_block('custcode/System Outputs','model/subsystem')
field = setfield(get_param('model/subsystem/systemOutput','RTWData'),'Top', ['test' char(10)]);
set_param('Copy_of_model_vergleich_atom/Subsystem1/test','RTWData',field);