Running .m and simulink (.slx) file together

I ran in to trouble while working with NI DAQ (USB 6251). I wanted to integrate everything is simulink and they dont provide block for counter (Can't use DIs). So I used function block with coder.extrensic() function and it works but my counter resets everytime. Following is my code,

function data = functionRead1()
    data = zeros(1,1); %Preinitialization
    coder.extrinsic('daq','addinput','read','table2array'); %define functions as external
    d = daq("ni"); % Add DAQ
    ch1 = addinput(d, 'Dev1', 'ctr0', 'Position'); % Add Inputs
    data = table2array(read(d)); %reads 1 scan cycle and returns accumulated value
end

So the problem is everytime counter resets and I get wront data read in code. Cant use while loop or if...else logic as it goes in loop or throws error.

I have .m file as well for code which works fine. It there any way I can run .m and .slx together on same machine? Or any other solution is fine.

Thanx in advance.

Answer 1

[Walter Roberson]

Use persistent. Check if the persistent variable is empty and if it is then configure it. Then either way, read from the daq.

Note: consider using OutputFormat 'Matrix' instead of the default table.

[Rutvik Shete]

Well I tried with ur solution. below is my code in matlab function block. Now its throwing error as d is not defined in all instances. May be because I am configuring DAQ in a IF statement and next execution I am neglecting that code.

Error "Variable 'd' is not fully defined on some execution paths. Function 'FunctionRead1' (#29.313.314), line 12, column 13: "d"".

Any solutions?

Thanx in advance.

function data = FunctionRead1
persistent n
coder.extrinsic('daq','addinput','read','table2array'); %define functions as external
if isempty(n)
    n = 0;
    data = zeros(1,1);
    d = daq("ni"); % Add DAQ
    %% Add Inputs
    ch1 = addinput(d, 'Dev1', 'ctr0', 'Position'); %
end
%% Set encoder type
data = read(d, 1, 'OutputFormat', 'Matrix');
n = 1;
end

[Walter Roberson]

persistent d

[Rutvik Shete]

Thanx a lot. Works really well. :)