Error using structure in Simulink "propagated signal hierarchy is inconsistent with the bus object"

I can't seem to implement a simple structure in Simulink. I've followed instructions in Matlab Documentation as best as I can, and gone thru many Q&A's in Matlab Answers forum, but no luck. Including this documentation: Attach Bus Signals to MATLAB Function Blocks .

I'm using R2015a.

The simulation error is as follows:

Error occurred while propagating bus signal hierarchy to input port 1 of the block 
'struct_test/Bus Creator1'. The propagated signal hierarchy is inconsistent with the 
bus object 'slBus1' specified on the block. This bus object directly or indirectly 
has a bus element with data type 'double' that does not match the propagated signal 
hierarchy.

Here's the Simulink model screenshot: A very simple model, but I plan to build on it for a much more complex analysis.

Code for Function 1:

function idx = fcn(u)

mystruct = struct('R',zeros(3));
idx = mystruct;

idx.R = rand(u+2);

Screenshot of Ports and Data Mgr for Function 1:

Screenshot of Bus Creator1 block properties:

Code for Function 2:

function y = fcn(idx_in)
idx_out = struct('R',zeros(3));
idx_out = idx_in;
y = sum(sum(idx_out.R)); % Sums all values of the 3x3 matrix.

Screenshot of Ports and Data Mgr for Function 2:

And finally the Bus Object used for the function blocks' structure data type.

Hope someone can help. Thanks in advance.

[Swarooph]

Since it is a simple model, can you attach that for quick reproduction of the issue?

[MarkD]

Swarooph, thanks for the response. Here's the SL model along with the script to load up the bus object 'slBus1' prior to running the model.

[MarkD]

Swarooph, please disregard previous uploaded files. Here's one zip with the correct files.

Answer 1

[Pramil]

Hey MarkD,

As the error suggests, the “Bus Creator” block expects a data of type “double”, but it receives a data of type “Bus” from the “MATLAB Function” block.

If you change the datatype of “MATLAB Function” block “idx” to “double” type and provide the “Bus Creator” block a “double 3X3” value, as defined in your “bus” element, it will resolve the issue.

I have updated your model “struct_test” to do the same and attached it for your reference. Before running the model just define "u = 3" in base workspace.

Hope it helps.