Disclosed is a portable device for collecting and processing continuous monitoring data. The device has a data interface configured to receive a stream of continuous monitoring data from a body-worn sensor, the continuous monitoring data being indicative of an analyte in a bodily fluid. A control is connectable to the data interface. The control controls a first mode of operation during which configuration parameters are established in response to receiving a start signal indicating a sensor session start of the body-worn sensor. The control also controls a second mode of operation during which the continuous monitoring data is collected and processed and also controls the switching from the first mode to the second mode. The control blocks further starting of the first mode for a remaining sensor session time after the switching to the second mode of operation. Also disclosed are a related medical system, method and computer program product.