Reset Constant value in Simulink from Matlab GUI

Hello,

In this very simplistic model of just a constant in Simulink, I wanted to RESET the value to zero by hitting the RESET button. Here is the callback code for the pushbutton control

% --- Executes on button press in RESET.
function RESET_Callback(hObject, eventdata, handles)
% hObject    handle to RESET (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
set_param('email_const/Constant','Value',0);

This is a screenshot of the Simulink (just a constant block).

How to go about successfully resetting the value to zero when the pushbutton is pressed. For your convenience, I have attached all the necessary files. Thanks.

Answer 1

[Abhi Sundararaman]

This is a very common issue, and I completely understand why!

The issue here is because in line 81 of "change_const.m", the value of Constant is being set to 0, rather than '0'.

When you use setparam, the value for the constant block should actually be a character array containing a value, rather than an actual value! I know that's very unintuitive, but the solution is pretty straightforward from here.

To fix your issue, just replace line 81 with the following:

set_param('email_const/Constant','Value','0'); %note that the 0 should be enclosed in single quotes.