Printing apparatus and a control method therefor

Abstract

While eliminating the need for a dedicated on-line selector switch, a printing apparatus and control method is provided to improve the processes required to replenish consumable printing materials consumed during the printing operation. Using a transport mechanism for transporting the print medium and a printing mechanism for printing to the print medium, the printing apparatus accomplishes the printing process based on data received from a host device, selectively switches between an on-line state and an off-line state and notifies the host device of the currently selected state. The printing apparatus further comprises sensors for detecting the presence of consumable products, including roll paper and ink, that are consumed by the printing process, a switch with two functional settings, and a control device. The two functional settings of the switch are an on-line function commanding a transition from the off-line state to the on-line state, and a second function for specifying the process, such as a paper feed operation, to be executed by the printing apparatus when consumable materials are replenished. The control device causes the printing apparatus to shift to the off-line state when a sensor detects that a particular consumable material is not present, and selects the on-line function of the switch when a sensor detects after switching to the off-line state that a particular consumable material is again present and available for printing.