How do I reset the signal output?

For example I have a ramp signal with slop=1 starting at t=0. When it gets to t=6 the signal value is 6. What I needed is reset the signal for the first 3 second so at t=0 to t=3 signal value is 0, and from t=3 to t=6 the signal value rise from 0 to 3 (not 6) at t = 6. I am a beginner of simulink, and spend so much time on this problem. Many thanks to who can find a approach solving this.

Answer 1

[Michelangelo Ricciulli]

I think that the answer you are searching is the "modulo" operation. Let's say your ramp is stored in vector y and you want the new ramp in y_new. Then in Matlab you should do

 y_new=mod(y,3);

In simulink, there should be a "Math Function" block, that you can configure to act like

 output=mod(input,3);

[Feng Zhou]

thanks for your reply, I wonder is there any way I can do it dynamically? For example the time that remap start to rise t = 3 can be decided by a input in simulink? I was trying to use the enable subsystem to accomplish it, but when the singal is enabled, the value always goes where i was suppose to be (=6 at t=6 at this case not 3 at t = 6). Thank you!!