How to encode signals of different data types stored in a bus object as an array of uint8 elements to send via UDP ethernet communication with DSPace?

My blocks scheme is the one in the picture attached. I would like to encode data as a single array of int8 elements s required as input for the TRX block.

What block could I use instead of the Byte Pack block to pack the mixed type data contained in a bus object? The byte pack block doesn't allow a bus object as an input.

I would like to avoid to input the signals individually in the byte pack block as for my application I have 100 signals to send.

Thanks for your help,

William

Answer 1

[Hornett]

I understand that you want to convert the bus object into a single array of int8 elements.

You can use a combination of “MATLAB Function” block and the built-in "int8" class to pack the mixed-type data from a bus object into a single array of int8 elements.

Inside the MATLAB Function block, write MATLAB code to extract the individual signals from the bus object and pack them into a single int8 array using the int8 function.

Here's an example code snippet:

function packedData = packData(busData)
% Initialize the packed data array
display(busData.signal1)
packedData = int8(zeros(1, 100));
% Define the signal field names
signalNames = cell(1, 100);
for i = 1:100
    signalNames{i} = sprintf('signal%d', i);
end
% Iterate over the signals and pack them into the array
for i = 1:100
    signal = busData.(signalNames{i});
    % Convert signal to a numeric type if necessary 
    if ~isnumeric(signal)
        signal = double(signal); % Convert to double or appropriate numeric type
    end
    packedData(i) = int8(signal); 
end
end

Refer to the documentation links attached below to get more information on “MATLAB function block” and “typecast function”.

MATLAB function block: https://www.mathworks.com/help/simulink/ug/what-is-a-matlab-function-block.html

int8 class: https://www.mathworks.com/help/matlab/ref/int8.html