I'm trying to add a counter to a Twido Suite program, but I don't know how to make it set to zero when the preset - C0.P - is reached.
The docs say the D output is activated, and the R input resets the counter to zero, but I can't connect the D output directly to the R input.
This is the List equivalent to this Ladder diagram above:
BLK %C0
LD BLINK
CU
END_BLK
I found a way by using a intermediate bit variable:
Related
I have been asked to obtain the first 15 triplets according to this series and this code ought to work. However, it does only produce a table (15*3) filled with zero rather than the 15 Pythagorean triplets? Any help will be welcome.
A = zeros(15, 3);
ii = 1;
for c = 5:120
c2=c^2;
for a=1:c-1
a2=a^2;
for b=a:c-1
if c2-(a2+b^2) == 0
A(ii,1) = a;
A(ii,2) = b;
A(ii,3) = c;
ii=ii+1;
if A(15, 1) ~= 0
flag = 1;
break
end
end
end
if flag == 1
break
end
end
if flag == 1
break
end
end
T1 = array2table(A);
disp(T1)
So, the code generated a correct table on application-restart before failing on all subsequent attempts. And, now I notice that the code runs successfully only for the first time after every relaunch of the application. (Resolved, thanks Dan Pollard.)
Also, interested in knowing if there is any way to not write an upper limit (120) into the code.
I don't think your if statement is ever satisfied. For example, for c=5, you'd expect a=3, b=4 to be a triplet. But you're only letting a and b go up to floor(sqrt(c-1)), which is 2.
Do you mean to let a and b go up to floor(sqrt(c2-1))?
Edit As the question has changed.
When you run the code, Matlab creates all the variables which you assign, and stores them in the workspace. This can be useful, but here it's hurting you as you have the variable flag which is stored as 1. This means that when the code runs, it checks if flag==1 after the first run through b, which it is, so the code ends. Resolve this by placing clear; at the beginning of your script.
There isn't a practical way to remove the upper limit on c. Matlab has the built-in variable Inf but at best Matlab won't let you use it in that context. Realistically you could just replace the 120 with a really large number, but this will take more time and more memory as the number gets bigger. Computers have a finite RAM to store matlab arrays in though, and there are infinitely many pythagorean triples, so doing the calculation without an upper limit will fail in some way.
I have the following problem:
I have written six scripts matlab. In the first script, the user must enter the variable n_strati (a number between 1 and 5). The first script allows you to make choices about computing models based on variables known or unknown , and runs them to n_strato=1. The second third fourth and fifth script follow the same procedure , respectively, for the layers 2-3-4-5, but in which the input parameters (not intended as a value) are different. For example:
for Strato1 performs calculations knowing the input variables A B E (and not C D F) , for Strato2 performs calculations knowing A C E (and not B D F) , for Strato3 knowing the variables B D F (and not A C E).
The sixth takes all the variables of the previous scripts and processes them to obtain the final result.
The first five scripts save the data using the command:
save Strato1 alpha beta gamma
% etc.
and the sixth script them "stores" with the command:
load Strato1
load Strato2
% etc.
But I have to make sure that:
if n_strati==1
I enter the data and choose the models in script1 jumping scripts 2-3-4-5 and proceeding with the final calculation through the script 6 .
if n_strati==2
I enter the data and choose the models for Strato1 in script1 and Strato2 in script2 jumping scripts 3-4-5 and proceeding with the final calculation through the script 6 .
and so on.
I wanted to know: how can I do?
Thank you for your cooperation.
The best way would be avoiding scripts and using functions. Even if you succeed in your plot of using multiple scripts, the code will be a big mess, hard to debug, etc. So the answer is simple:
Say NO to scripts!
It is as easy as adding a signature and declaring your input and output.
I am trying to mimic the behavior of MATLAB's Simulink relay block with just MATLAB code.
My code is as follows (not familiar with persistent variable? click) :
function out = fcn(u,delta)
persistent y;
if isempty(y)
y = 0;
end
if u >= delta
y = 1;
elseif u <= -delta
y = 0;
end
out = y;
When I look to the output and compare with the real relay block I see :
Where does the difference come from?
Both blocks insert the same sample time, does the relay block have something extra to show the discontinuity?
Simulink block diagram download
I'm not quite sure about this explanation, maybe somebody can support it.
The MATLAB function Block does not support Zero-Crossing Detection, the Relay Block does. That means the latter knows in advance, when your sine will reach the threshold delta and sets the output accordingly to the correct time. The MATLAB function Block needs 2 or more steps to detect the slope (respectively the crossing of the threshold). So from one step to another it realizes that the condition for the new output was set and updates the output and you get a ramp, not a step.
C/C++ S-Functions do have Zero-Crossing Detection - though it seems quite complicated.
I am trying to implement a counter logic in SIMULINK where
in1, in2 are inputs
out1 is the output
if in2 = 0, out1 = 0;
if in2 = 1, out1 = 1 after x high edges of in1
I have tried using "Detect Rise Positive" block but failed miserably because I don't have sufficient experience of implementing a timing diagram correctly in SIMULINK. Could anyone kindly point me to the right direction?
Update
An approach I have taken since I posted this question is the "Triggered and enabled subsystem". I am trying to set it up so that:
in2 becomes the enable signal
in1 becomes the trigger
in2 becomes the intput to the subsystem
Out1 becomes the output of the subsystem
But I think that the above was rubbish. Unfortunately it is not VHDL where I could have implemented it using 4-5 lines of description of the hardware logic.
Using a Triggered and Enabled subsystem is the right approach, but your inputs (and no doubt what's inside the subsystem) needs to be modified.
Don't have any input to the subsystem (other than the trigger and enable signals).
Inside the subsystem,
set the enable block property to reset the state when disabled.
set the outport property to reset when disabled and give the initial condition as 0.
create a counter out of a constant (value=1), a summation and a unit delay block.
feed the counter into a Compare to Constant block set to the 'x' value in your question.
feed that block to the outport.
When enabled, the counter should count the required number of steps (when triggered) before the output goes high.
A counter logic can be implemented very easily in simulink. Take a switch,give the control input as int1. If int1 is 1 ur output shuld be 0 else take another switch give its control input as int2. if int2 is 1 ur output shuld be 1+ previous value given in feedback funit delay block
I have recently started learning MatLab, and wrote the following script today as part of my practice to see how we can generate a vector:
x = [];
n = 4;
for i = i:n
x = [x,i^2];
end
x
When I run this script I get what I expect, namely the following vector:
x = 0 1 4 9 16
However, if I run the script a second time right afterwards I only get the following output:
x = 16
What is the reason for this? How come I only get the last vector entry as output the second time I run the script, and not the vector in its entirety? If anyone can explain this to me, I would greatly appreciate it.
Beginning with a fresh workspace, i will simply be the complex number 1i (as in x^2=-1). I imagine you got this warning on the first run:
Warning: Colon operands must be real scalars.
So the for statement basically loops over for i = real(1i):4. Note that real(1i)=0.
When you rerun the script again with the variables already initialized (assuming you didn't clear the workspace), i will refer to a variable containing the last value of 4, shadowing the builtin function i with the same name, and the for-loop executes:
x=[];
for i=4:4
x = [x, i^2]
end
which iterates only one time, thus you end up with x=16
you forget to initialize i.
after first execution i is 4 and remains 4.
then you initialize x as an empty vector but because i is 4 the loop runs only once.
clear your workspace and inspect it before and after first execution.
Is it possibly a simple typo?
for i = i:n
and should actually mean
for i = 1:n
as i is (probably) uninitialized in the first run, and therefore 0, it works just fine.
The second time, i is still n (=4), and only runs once.
Also, as a performance-tip: in every iteration of your loop you increase the size of your vector, the more efficient (and more matlaboid) way would be to create the vector with the basevalues first, for example with
x = 1:n
and then square each value by
x = x^2
In Matlab, using vector-operations (or matrix-operations on higher dimensions) should be prefered over iterative loop approaches, as it gives matlab the opportunity to do optimised operations. It is also often more readable that way.