How check fot the of a unit root exist in a model?

Dear all,
I would like to know how can I proceed to verify if my model is free of unit root issue.
i.e. is there any specific command that I can use to check the consistency of my model in this regard.
Thanks,
Ful
I would like to know how can I proceed to verify if my model is free of unit root issue.
i.e. is there any specific command that I can use to check the consistency of my model in this regard.
Thanks,
Ful