MATLAB Answers


How to send continuous data from simulink block

Asked by Rahul kumar on 17 Aug 2012
I have to develop a model in Simulink which can send data continuously, the sent data should be stored in a block and if it reaches some predetermined value. It should trigger the next block.
I increase the value of a constant block by this code..!
for a=1:0.1:10
set_param('MyModelName/Constant','Value',num2str(a)) %send a to the model
pause(1) %pause for 1 second
but it is not sending the data continuously, everytime i have to press Run button.
let me know ur idea
Thanks in advance


To explain more clearly..
first i have a constant block which should to send data continuously ( 1 to 10 with interval 0.2)
The next block should take this data continuously and store it.. and if it reaches a threshold value (say 6)..! it should trigger the next block :)
yes it is a signal coming out of that conditional block, not data
Is my question clear?

Sign in to comment.



3 Answers

Answer by Ryan G
on 17 Aug 2012

I don't think this code does what you think it does. There is no real-time operations between MATLAB and Simulink, so when you pause for 1 second it could take 1.5 seconds to process the next point in the sim or it could take 100 seconds in the sim depending on how fast it moves.
Try pre-packaging the data with a Time and Data vector and utilizing a To Workspace block or an Inport. For continuity you want to enable interpolation.

  1 Comment

I think Ryan meant to say "From Workspace" instead of "To Workspace" block. :)

Sign in to comment.

Answer by Albert Yam
on 17 Aug 2012

Why do you need the 'pause'? If you want an input to 'change over time', use a look-up table, or signal generator.
hm..deja vu

  1 Comment

You still have yet to explain why you need to store the value, and you just reiterated your wording, almost verbatim, so no, not more clear.
clock -> Look-up(n-D) -> Compare to Constant ---> Scope(2)
--------------------------> Scope(1)
table dimensions = 1
First input (row) = 0:length(a)-1
Table data = a %where in workspace: >> a = 0:0.1:10;
Compare to Constant
Operator = >
Constant value = 5

Sign in to comment.

Answer by Rajan
on 20 Aug 2012

I don't think you can change a value used in constant block ,as the name of the block suggests ,it is a constant value through out the execution.
Don't sent the data from a constant block , instead make a simple addition which increments by 0.2 every time with in the model(not from the code) and send the output of sum block to your data store block . Or compare the output of sum block with comparator block (==6).
I hope this serves your cause.

  1 Comment

yes this makes more sense..! i ll try to this ! thank you :)

Sign in to comment.