The present invention relates to a system for data transfer between a server and a respirator which comprises a source for breathing gas, and at least one interface to enable a data transfer, a device for determining data, a control unit, a memory, and a timer unit for specifying a system time. The respirator is configured to give the data a timestamp, to store them and to transfer them at a later point in time. The timestamp is designed so that it cannot be adjusted, or can only be adjusted to a limited extent to a tolerance window.
