Printer, host computer, printer system, and printing system control method

Abstract

A printer that is communicably connected over a network to a host computer and operates according to a command or data sent from the host computer, comprising a reception unit for receiving the command or data sent from the host computer, a timer for counting elapsed time after the command or data is received, and an error detection unit for reporting that the host computer is in an error state when the command or data from the host computer is not received within a predetermined time after the timer starts counting the elapsed time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view of a printer according to a preferred embodiment of the invention.

FIG. 2 is an oblique view of the printer shown in FIG. 1 with the two front covers opened to access the inside of the printer.

FIG. 3 is a block diagram showing the electrical arrangement of the host computer and printer in a preferred embodiment of the invention.

FIG. 4 is a function block diagram showing the internal processes of the host computer and printer.

FIG. 5 is a flow chart describing the error detection reporting process of the error detection reporting system rendered by the host computer and printer.

FIG. 6 is a schematic diagram of a conventional POS system.

Claims

1. A printer that is communicably connected over a network to a host computer and operates according to a command or data sent from the host computer, comprising: a reception unit for receiving the command or data sent from the host computer;a timer for counting elapsed time after the command or data is received; andan error detection unit for reporting that the host computer is in an error state when the command or data from the host computer is not received within a predetermined time after the timer starts counting the elapsed time.

2. The printer described in claim 1, wherein the error detection unit resets the elapsed time of the timer and restarts counting the elapsed time when the command or data from the host computer is received within the predetermined time.

3. The printer described in claim 1, further comprising: a printing control unit for printing to a print medium;wherein the error detection unit causes the printing control unit to print a message reporting the host computer error state.

4. The printer described in claim 1, further comprising: a display unit for displaying a status of the printer;wherein the error detection unit causes the display unit to present a display reporting the host computer error state.

5. The printer described in claim 1, further comprising: a sound source for reporting a status of the printer by sound;wherein the error detection unit causes the sound source to emit a sound reporting the host computer error state.

6. The printer described in claim 1, further comprising: a non-volatile storage unit for storing the predetermined time;wherein the predetermined time is set based on a configuration command sent from the host computer.

7. A host computer for sending a command or data to a printer that is communicably connected to a printer over a network, comprising: a printer control command generating unit for regularly sending a reset/start command to the printer at an interval that is shorter than a predetermined time set in the printer;wherein the host computerenters an error state when the command or data from the host computer is not received within the predetermined time after the command or data including the reset/start command is received.

8. A printing system including a host computer and a printer that is communicably connected over a network to the host computer and operates according to a command or data sent from the host computer, wherein: a predetermined time for confirming host computer operation is set in the printer;the host computer comprises a printer control command generating unit for regularly sending a reset/start command to the printer at an interval that is shorter than the predetermined time; andthe printer comprises an error detection unit for reporting that the host computer is in an error state when the command or data including the reset/start command from the host computer is not received within the predetermined time after the printer receives the command or data including the reset/start command.

9. The printing system described in claim 8, wherein the printer resets an elapsed time count and restarts counting the elapsed time count when the command or data from the host computer is received within the predetermined time.

10. The printing system described in claim 8, wherein: the printer comprises a printing control unit for printing to a print medium; andthe error detection unit causes the printing control unit to print a message reporting the host computer error when the command or data including the reset/start command from the host computer is not received within the predetermined time.

11. The printing system described in claim 8, wherein: the printer comprises a display unit for displaying a status of the printer;and the error detection unit causes the display unit to present a display reporting the host computer error when the command or data including the reset/start command from the host computer is not received within the predetermined time.

12. The printing system described in claim 8, wherein: the printer comprises a sound source for reporting a status of the printer by sound;and the error detection unit causes the sound source to emit a sound reporting the host computer error when the command or data including the reset/start command from the host computer is not received within the predetermined time.

13. The printing system described in claim 8, wherein: the printer comprises a non-volatile storage unit for storing the predetermined time; andthe predetermined time is set based on a configuration command sent from the host computer.

14. A control method for a printing system including a host computer and a printer that is communicably connected over a network to the host computer, operates according to a command or data sent from the host computer, and has a predetermined time for confirming host computer operation set in the printer, the control method comprising: sending a reset/start command from the host computer to the printer regularly at an interval that is shorter than the predetermined time; andissuing a report from the printer that the host computer is in an error state when the printer does not receive the command or data including the reset/start command from the host computer within the predetermined time after the printer receives the command or data including the reset/start command.

15. The printing system described in claim 8, wherein: the host computer is configured to send a configuration command to change an error detection method setting of the printer.

16. The printing system described in claim 15, wherein the configuration command is changed when the host computer is powered on and when the error detection settings are changed while the system is operating.

17. The printing system described in claim 15, wherein the configuration command is changed when error detection settings changed.