Generate ramp signal for a certain time in simulink

Greetings ... I am new to the community, as well as Matlab, I would like to know how I can generate a ramp signal which lasts a certain time, since the ramp signal of the source library does not have the possibility to change this configure this parameter. So far I have tried to implement my own block in MATLAB fuction.

function y = fcn(slope,rise_time,start_time)

%#codegen

t = start_time:rise_time;

y = slope*t;

But I only get the following error.

• Output 'y' you have variable size but the upper bound is not specified;explicit upper bound must be provided.*

[VARSSHA P]

ramp signal with time period 4 secs

Answer 1

[Siddharth Tripathi]

Hey Cesar,you can use two ramp functions in simulink with the starting time of one set at the time when you want to start the ramp function and another with its slope having a negative value of and starting time set to when you want to end the ramp input.

[Wycliff Dembe]

Thanks you've saved my day

Answer 2

[TAB]

Function which you have written will generate whole Ramp in just onec call (one sample).

In Simulink, this function will be called every sample time. So this is not going to work.

Also in simulink, time base will be generated by simulink only. If you want you can read the current simulation time using Clock block.

So you can use the combination of Clock, Multiply and Compare blocks to create a signal which ramps up to cirtain time.

[Cesar Herbas Zeballos]

Thank you for answering TAB, I will follow your advice ... although I commented that I have some doubts when using the MATLAB function to be able to create my own customized blocks, I certainly do not know if it is the best option, since in the future I would like to generate curves graphics that are based on certain input parameters.