Thank you, I think I have understand the training process. My problem now is in the prediction phase.When it comes to predicting I  have  only one timestep available each time.
For example I want to predict a  sample with shape (1,1,27) and based  on the outcome of  that prediction I want to predict the next sample with the same shape.
If I try to predict a sample with shape (1,80,27) I get 80 different outcomes  which is not what I want.
I want to predict one timestep at time until I reach timestep 80, then the next sequence comes in.
Sorry again if I am  not very clear