Thank you very much. But when I run the model, the simulation failed. If I cut the line between sine souce and custom component, the component works very well.

From the equations, the component's input is sin(2*Pi*t). If I want the component's input is an undefined signal, namely, u(t),then how can I do this?   

Best regards.

Today I know about the acquisition. I hope maple will grow more stronger in the new year.

@Kamel 

Thank you very much! Your answer is very timely.

Best wishes.

@Kamel 

Thank you very much! Your answer is very timely.

Best wishes.

Thanks a lot! You are right. I lost the ground block.

By the way, I upload a new picture. Can you tell me the answer?

Best regards.

Thanks a lot! You are right. I lost the ground block.

By the way, I upload a new picture. Can you tell me the answer?

Best regards.

Thank you for telling me these useful approaches.

Best regards,

Wang.

Thank you for telling me these useful approaches.

Best regards,

Wang.

Thanks again for your help.

Best regards,

Wang.

Thanks again for your help.

Best regards,

Wang.

Thank you for your attention.

Thesd days I find a command can solve my problem:

arrow(Vector([0,0,7*Pi]),Vector([0,0,-4.5*Pi]),1,5,0.2,cylindrical_arrow,color=blue,fringe=green);

Best wishes.

Thank you for your attention.

Thesd days I find a command can solve my problem:

arrow(Vector([0,0,7*Pi]),Vector([0,0,-4.5*Pi]),1,5,0.2,cylindrical_arrow,color=blue,fringe=green);

Best wishes.

Thank you for giving me some useful advices.

Best wishes.

Thank you for giving me some useful advices.

Best wishes.

Your answer is very perfect! From it I can learn a lot of useful skills.Thank you very much!

Best regards.