Connecting system, injection system for the injection of a medical fluid and method of operating such an injection system

A connecting system for connecting a medical tubular line to a medical fluid transfer system, the tubular line including a plug-in component with a first fluid channel and the fluid transfer system including a coupling component with a second fluid channel. The plug-in component can engage in the coupling component to establish a passageway for a medical fluid, which passageway connects the fluid channels to one another. By disposing a first passive transponder in the plug-in component and a second passive transponder in the coupling component at a distance below a predefined threshold value relative to one another, communication of a read/write unit with both transponders via a single antenna is made possible when the plug-in component is engaged in the coupling component so that identification data for the identification of the tubular line and the fluid transfer system stored in the transponders can be read by a read/write unit via a single antenna.