An imaging apparatus capable of outputting a sensed image to a printing apparatus issues a print request command containing a parameter for designating a print mode to a PD printer apparatus connected via an interface. The imaging apparatus transmits image data corresponding to the print mode on the basis of a data request from the PD printer apparatus. The imaging apparatus transmits, to the PD printer apparatus, the print request command in which the parameter is changed to invalid data, thereby designating printing of the transmitted image data.