Abstract: At each local data collection site, the local collection devices are arranged so as to identify and collect the data originating from acquisition devices, which data is transported on a first communication network serving the local site, and containing a local storage device for storing this data. The central site contains a device for transferring, via a second communication network, the data stored in each local site in the local collection device to the central monitoring and processing device, each data transfer being asynchronously initiated by the local collection device concerned at a moment in time or within a time interval which has been determined beforehand and communicated by the central monitoring and processing device.