how to change variable value in lookup table during simulation in Simulink?

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Hello,
so I have a 2 table lookup; first table has: P (48 values) and time(1:1:48); and the second table has: load Q (48 values) and time(1:1:48);
at some time ; for example at time=6; i want to change the value of P to 9; how can change variable value at the same time of simulation running?
I tried to use Matlab function to change the value of P but it didn't work;
the code is:
function Pref= fcn(loadref,currenttime, P )
persistent loadrefold;
% Initialize persistent variable
if isempty(loadrefold)
loadrefold = 0;
end
if loadref ~= loadrefold;
updatetime = round(currenttime+1)
P(updatetime,1)=loadref;
loadrefold=loadref;
Pref=P;
else Pref=P;
end
end
  2 Comments
Sam Chak
Sam Chak on 20 Feb 2024
Based on your clear description, it seems that there are two Lookup Tables involved. You mentioned that each Lookup Table has two inputs to the block, one being the load and the other being the time. However, I only see the time input (Hour of the Day) in the Simulink model. Am I missing something?
Additionally, at time , you mentioned that you want to set the value of Load to 9, which seems to be a fixed value not dependent on the Lookup Table. Do you intend for the Load to remain at 9 for time t > 6 until the end of the simulation?
jana nassereddine
jana nassereddine on 20 Feb 2024
i have inside the lookup table; i have 2 inputs; i will show you a picture; as for th etime; no only for a specific time i want a specific value;

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Answers (2)

Jon
Jon on 20 Feb 2024
You could use the step block, found under Simulink>Sources for this purpose

Fangjun Jiang
Fangjun Jiang on 20 Feb 2024
Usually, using Dashboard blocks allow you to change variable values interactively during simulation
  7 Comments
Fangjun Jiang
Fangjun Jiang on 21 Feb 2024
If the value of "P" is created or modified by this MPC or the MATLAB function, then this solution would be perfect too. Make that "P" an output of this MPC or the MATLAB Function block, remove the Constant block, feed "P" to the "T" port of the 1-D Lookup Table block, making it a dynamic lookup table.

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