CSCS provides a data transfer service to get your files from/to CSCS file systems using globus.org endpoints: please check (External Transfer) for details.
CSCS also provides a Slurm queue xfer available on Piz Daint to transfer files from/to internal CSCS file systems, check the following link for this use case (Internal Transfer).
The Slurm queue xfer can submit jobs directly on the nodes of the cluster supporting data transfer. Direct access via ssh to the nodes of this cluster is not allowed.