Powering a point of sale printer and coupon printer from a shared power supply

A point of sale (POS) method, comprising:

• electronically inputting items for purchase;
• selectively generating primary print commands in response to the inputted items;
• transmitting power and the primary print commands through a Universal Serial Bus (USB) connection to a primary printer;
• printing at the primary printer according to the primary print commands using the power transmitted to the primary printer through the USB connection;
• generating an indication representing the power drawn by an auxiliary printer in response to executing one or more received auxiliary print commands, wherein the auxiliary print commands are generated independently from and asynchronously with the primary print commands;
• blocking, in response to the indication exceeding a threshold, the primary print commands from being received at the primary printer thereby stopping the process of printing at the primary printer, wherein the primary printer remains coupled to the USB connection while the primary print commands are blocked;
• and
• resuming the printing process at the primary printer in response to the indication no longer exceeding the threshold.

A computer program product comprising computer usable program code embodied on a non-transitory computer usable storage medium, the computer program product comprising:

• computer usable program code for electronically inputting items for purchase;
• computer usable program code for selectively generating primary print commands in response to the inputted items;
• computer usable program code for transmitting the primary print commands through a Universal Serial Bus (USB) connection to a primary printer;
• computer usable program code for printing at the primary printer according to the primary print commands using the power transmitted to the primary printer through the USB connection;
• computer usable program code for generating an indication representing the power drawn by an auxiliary printer in response to executing one or more received auxiliary print commands, wherein the auxiliary print commands are generated independently from and asynchronously with the primary print commands;
• computer usable program code for, in response to the indication exceeding a threshold, blocking the primary print commands from being received at the primary printer thereby stopping the process of printing at the primary printer, wherein the primary printer remains connected to the USB connection while the primary print commands are blocked;
• and
• computer usable program code for resuming the printing process at the primary printer in response to the indication no longer exceeding the threshold.