JPH08272566A - Remote printing system - Google Patents

Abstract

PURPOSE: To preferentially print a printing job which was being used immediately before the occurrence of a' fault even in the case of the occurrence of the fault by providing a host computer with a communication restart processing part for restarting communication with a network printer, and providing the network printer with a printer initialization processing part to restart the communication with the host computer. CONSTITUTION: At the time of starting the communication for printing, a connection state in course of the communication by a remote printing processing part is registered previously in a memory 115 by the host computer 110, and in the case where the interruption or the reset of the power supply of the network printer 120 is executed during the printing, the communication restart processing part 116 waits for a communication starting request from the network printer 120. On the other hand, in the network printer 120, at the time of starting the communication for the printing, a printing control part 121 registers previously the connection state in course of the communication in a non-volatile memory 124, and at the time of turning-on or resetting the power supply, the printer initialization processing part 125 requests the start of the communication with the host computer 110 registered in the non-volatile memory 124.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote printing system for printing by sharing a network printer connected to a network with a plurality of hosts.

[0002]

2. Description of the Related Art In recent years, a remote printing system has become widespread in which a plurality of hosts connected to a network share a printer for printing. An example of such a remote printing system is described in, for example, Japanese Patent Laid-Open No. 4-18631.

Hereinafter, a remote printing system in which a plurality of hosts connected to a network share a printer,
A general conventional example will be described with reference to FIG.

In the example of FIG. 7, the host computer 110 connected to the network 100 shares the network printer 120 with other host computers in the network to perform printing. In FIG. 7, only one host computer 110 and one network printer 120 are shown, but a plurality of host computers and a plurality of printers may be used.

The host computer 110 is a computer that shares the network printer 120 with other host computers connected to the network 100 and performs printing while controlling the operation of the network printer 120 according to an instruction from the user. The host computer 110 transmits a print program 111 for generating a print job and instructing printing by a network printer, and a remote print control unit 112 for transmitting an instruction from the print program 111 to the network computer 120 and transferring the print job. And a network protocol 113 for providing a communication means between the host computer 110 and the network printer 120.

The network printer 120 is a printer that prints according to an instruction from the host computer 110. The network printer 120 has a print control unit 121 that controls printing according to instructions from the host computer 110, a printer engine 122 that controls the printer mechanism to perform printing, and an initialization process when power is turned on or reset. The printer initialization processing unit 125 and the network protocol 113.

The network printer 120 is one of the constituent elements of the network 100, and can operate independently. That is, the network printer 120 can be connected to the network 100 as a component on the network even when the power of the host computer 110 is cut off or is not connected to the network 100, and the operating state of the host computer 110 is changed. The connection to the network 100 may be disconnected irrespective of the power being cut off or the power being reset.

In the conventional network printer 120,
At power-on or reset, the printer initialization process 125 initializes information about the previous connection state, and all the information is lost.

[0009]

As described above, when the initialization process 125 is completed and the printer is ready for printing, the network printer 120 makes the network 10
A communication start request from any host computer within 0 can be accepted. Therefore, if the power of the network printer 120 is cut off or reset during the transfer of the print job, the host computer 110 will restart the network operation for the next printing when the printer becomes ready for printing. Even if a request to start communication with the printer 120 is made, another host computer in the network 100 may start communication with the network printer 120 and print.

Therefore, for example, if the power of the network printer 120 is cut off or reset while the print job of 10 pages is transferred and the network printer 120 is printing the fifth page, the display device 117 is operated by the user. Even if the user confirms the content of the failure report displayed on the screen, and then instructs the printing from the fifth page when the network printer 120 is ready to print again, another host computer from the network 100 There is a problem in that the print job is executed first, other documents are mixed in between 10-page documents, and printing of the remaining pages is kept waiting until the other print jobs are completed.

As described above, in the conventional remote printing system, even after the power of the network printer 120 is cut off or reset during printing, even if the printer is ready to print again, the user who is printing immediately In addition, there is a problem that reliability is low such that a desired document cannot be obtained, and other documents are mixed in and sorting work is required.

An object of the present invention is to provide a remote printing system that solves the above problems.

[0013]

According to the present invention, a memory for registering a connection state during communication in a host computer, a communication restart processing unit for restarting communication with a network printer 120, and communication restart. And a timer for monitoring the. Further, a non-volatile memory for registering the connection status during communication with the network printer 120 and a timer for monitoring the restart of communication are provided, and the printer initialization processing unit restarts communication with the host computer. It is characterized by

[0014]

In the host computer, at the start of communication for printing, the remote print processing unit registers the connection state during communication in the memory, and when the power of the network printer 120 is cut off or reset during printing, communication is performed. The restart processing unit waits for a communication start request from the network printer.
Further, the communication resumption processing unit activates a timer, and when the timer times out, displays that communication failure has occurred on the display device, and ends the processing.

On the other hand, in a network printer, at the start of communication for printing, the print control unit registers the connection state during communication in a non-volatile memory, and when the power is turned on or reset, the printer initialization processing unit makes the non-volatile state. Request to start communication with the host computer registered in the local memory. Further, the printer initialization processing unit starts a timer, and when the timer times out, terminates the communication restart processing and accepts another communication start request.

Since the communication restart processing section and the printer initialization processing section operate as described above, the communication at the time of power-off or reset of the network printer can be restarted with priority.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 1 shows an example in which a host computer 110 connected to the network 100 prints with a network printer 120 connected to the network 100. In FIG. 1, one host computer 110 and one network printer 120 for printing are shown, but they may be composed of a plurality of host computers and a plurality of network printers.

The host computer 110 is a computer that shares the network printer 120 with other host computers connected to the network 100 and performs printing while controlling the operation of the network printer 120 according to an instruction from the user. The host computer 110 generates a print job and a print program 111 for instructing printing by the network printer 120.
And a remote print control unit 112 for transmitting an instruction from the print program 111 to the network printer 120 to transfer a print job, and a network protocol 113 for providing a communication means between the host computer 110 and the network printer 120. A communication restart processing unit 116 for restarting communication with the network printer 120 after recovery from communication failure, a timer 114 for monitoring the restart of communication, and a memory 115 for registering a connection state during communication. Input device 118 and display device 11
7 and 7. The input device 118 may be a pointing device such as a mouse, a keyboard, a button, a panel switch, or any other device.
7 may be a CRT, a liquid crystal panel, or any other type.

The network printer 120 is a printer that prints according to an instruction from the host computer 110. The network printer 120 has a print control unit 121 that controls printing according to instructions from the host computer 110, a printer engine 122 that controls the printer mechanism to perform printing, and an initialization process when power is turned on or reset. Printer initialization processing unit 125, and a timer 123 for monitoring the resumption of communication
And a non-volatile memory 124 for registering the connection state during communication, and a network protocol 113.

When the user gives an instruction to print a document from the input device 118, the print program 111 uses a page description language (PDL: Page Descripti) based on the document file and the setting information input by the user regarding the print format such as the number of copies.
On language), a print job in which the content of the document is described is created, and the print job is passed to the remote print control unit 112. Print program 111 and remote print control unit 112
A spool or a queue may be provided between the printer and the printer so that a plurality of print jobs can be stored in the spool, and the remote print control unit 112 sequentially takes out print jobs and prints them.

The remote print control unit 112 communicates with the network printer 120 by the communication protocol 113. In the network printer 120, the print controller 12
1 communicates with the host computer, and according to the instruction from the host computer 110, the printer engine 12
2 to print the print job.

If the power of the network printer 120 is cut off or reset while the host computer 110 is transferring a print job to the network printer 120, communication end processing according to the communication protocol 113 is performed. Communication protocol 113
Reports a communication failure to the remote print control unit 112.

FIG. 2 shows an operation flow of the remote print control unit 112.

Hereinafter, the remote print control unit 1 will be described with reference to FIG.
The operation of 12 will be described in detail.

The remote print control unit 112 receives the print job and, as shown in FIG. 2, requests the network printer 120 to start communication using the network protocol 113 (201). The communication start request is issued by issuing a connection request function (connect) when TCP / IP is used as the network protocol, for example.

When a request for communication with the network printer 120 is accepted, the remote print control unit 112 registers in the memory 115 a set of the host ID of the communication partner and the host ID of itself and the port number used for communication (202), and communicates. No failure has occurred (203), and communication has not yet been terminated (20
In the case of 4), the print job is transferred (205).

When the transfer of the print job is completed and the communication with the network printer 120 is ended (20
4) The pair of host ID and port number of the communication partner and the self registered in the memory 115 is erased (207), and the process ends.

FIG. 3 shows an operation flowchart of the network printer 120.

The operation of the network printer 120 will be described in detail below with reference to FIG.

In the network printer 120, the print control unit 121 receives communication using the network protocol 113 (301). The reception of the communication start request is performed by issuing a connection request reception function (listen) and a connection establishment function (accept) when TCP / IP is used as the network protocol, for example.

Upon receiving the communication from the host computer 110, the print control unit 121 stores a set of the host ID and port number of the communication partner and itself in the non-volatile memory 124.
(302), no communication failure occurred (303),
When the communication is not yet ended (304), the print job is received, the document content is drawn according to the PDL described in the print job, and the document content is passed to the printer engine 122. The printer engine 122 controls the printer mechanism. Printing is performed (305).

When the transfer of the print job is completed and the communication with the host computer 110 is ended (304),
The set of the host ID and port number of the communication partner and the self registered in the non-volatile memory 124 is erased (307), and the process is ended.

The network printer 120 performs communication restart processing when a communication failure occurs during transfer of a print job (303), power is turned on, or reset (306). A reset occurs when the reset button is pressed or an unrecoverable hardware failure occurs.

FIG. 5 shows a flow of communication restart processing in the network printer 120.

The communication restart processing procedure in the network printer 120 will be described below with reference to FIG.

The printer initialization processing unit 125 confirms whether the combination of the host ID and the port number is registered in the non-volatile memory 124 (501), and if registered, activates the timer 123 (502). Non-volatile memory 124
A request to start communication is made to the host 110 registered in (503), and a communication restart request message 601 shown in FIG.
Is transmitted (504).

Next, the printer initialization processing section 125 receives a response message from the host computer 110 (505). The response message has exactly the same format as the communication restart request message 601 shown in FIG. 6, and the host computer 110 copies the content of the memory 115 and transmits it. When the combination of the host ID and the port number in the response message matches the content of the non-volatile memory 124 (50
7) Then, the set of the host ID and the new port number is registered in the non-volatile memory 124 (508), and the communication for printing is restarted (509).

If the combination of the host ID and the port number in the response message does not match the contents of the non-volatile memory 124 (507) or the timer 123 times out (506), the printer initialization processing unit 125 determines that the non-volatile The contents of the property memory 124 are erased (510), and the process ends.

When a communication failure occurs during transfer of a print job (203), the host computer 110 performs communication restart processing (206).

FIG. 4 shows a flow of communication restart processing in the host computer 110.

Hereinafter, the host computer 1 will be described with reference to FIG.
The communication restart processing procedure in 10 will be described.

The communication resumption processing unit 116 confirms whether or not the combination of the host ID and the port number is registered in the memory 115 (401), and if registered, activates the timer 114 (402) and makes a communication request. Accept (403).

There is a communication request from the network printer 120 (404), and the host ID in the communication request message
If the combination of the port number and the port number matches the contents of the memory 115 (405), the memory 115
Is copied and transmitted (406), and the set of host ID and new port number is registered in the memory 115 (40
7) Resume communication (408).

When the combination of the host ID and the port number in the communication request message does not match the contents of the memory 115 (4
05), copy the contents of the memory 115 to the response message (601) and send it as a communication refusal response (409),
The communication request is accepted again (403). The communication request may be accepted again without transmitting the communication refusal response (409). In this case, the network printer 12
At 0, a time-out occurs (506) and the process ends.

When the timer 114 in the host computer 110 has timed out (410), the contents of the memory 115 are erased (411), the fact that a communication failure has occurred is displayed on the display device 117 (412), and the processing is terminated. To do.

When a communication failure occurs during transfer of a print job by the host computer 110 (203), a message indicating that the communication failure has occurred is displayed on the display device 117, and the user is inquired whether or not to perform communication restart processing. The communication restart processing may be performed when the user gives an instruction to restart the communication from the input device 118.

Network protocol 1 used in the embodiment
13 is OSI, TCP / IP, UDP / IP, Net
The network 100 may be LA, LANMANAGER, or any other type.
N, packet switching network, leased line, telephone line, or any other type may be used.

Further, in the embodiment, the set of the host ID and the port number is registered in the memory 115 and the non-volatile memory 124, but the set of the host and the communicating process with respect to the communication partner and itself can be specified. Any information such as a process number and a random calculation result may be used as long as the information is available.

In the embodiment, the example in which the network printer 120 makes a communication restart request to the host computer 110 at the time of restarting communication has been described. On the contrary, the host computer 110 makes a communication restart request to the network printer 120. You may do it. In this case, the network printer 120 accepts the communication restart according to the flow of the communication restart processing shown in FIG.
10 requests the restart of communication according to the flow of the communication restart process shown in FIG. In this case, the host computer 1
10 requests the host registered in the memory to start communication at a fixed time interval (503), and the network printer 120 does not display the failure occurrence on the display device (412). Instead, the host computer 110 However, after the memory contents are erased (510), the failure occurrence is displayed on the display device.

Further, in the embodiment, the remote print control unit 1
12 and the print control unit 121 have registered in the memory the pair of host ID and port number of the communication partner and itself.
The communication protocol 113 may manage the connection state using the memory 115 and the non-volatile memory 124, and the communication protocol 113 may perform registration processing in the remote print control unit 112 and the print control unit 121.

[0053]

According to the present invention, when the power of the network printer is cut off, the reset process is performed in the network printer, or the communication failure occurs while the host computer is using the network printer for printing. Also, the print job of the host computer that was being used immediately before that can be preferentially printed.

As a result, even if an error occurs during printing of a document of a plurality of pages using the network printer, a print document by a print job submitted by another host computer or another print program can be interrupted. Without, it is possible to obtain the desired printed document.

That is, according to the present invention, it is possible to construct a highly reliable remote printing system with a configuration in which a plurality of host computers share a network printer in the network.

[Brief description of drawings]

FIG. 1 is a block diagram of a remote printing system according to an embodiment of the present invention.

FIG. 2 is a flowchart of the operation of a remote print control unit.

FIG. 3 is a flowchart of the operation of the network printer.

FIG. 4 is a flowchart of an operation of communication restart processing in the host computer.

FIG. 5 is a flowchart of an operation of communication restart processing in the network printer.

FIG. 6 is an explanatory diagram showing the format of a communication restart request message.

FIG. 7 is a block diagram of a conventional remote printing system.

[Explanation of symbols]

 100 ... Network, 110 ... Host computer, 111 ... Print program, 112 ... Remote print control section, 113 ... Network protocol, 114 ... Timer, 115 ... Memory, 116 ... Communication restart processing section, 120 ... Network printer, 121 ... Print control Reference numeral 122 ... Printer engine, 123 ... Timer, 124 ... Non-volatile memory, 125 ... Printer initialization processing unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06F 13/00 301 G06F 13/00 301K 351 7368-5E 351M (72) Inventor Takuya Shimakawa Kawasaki, Kanagawa Prefecture No. 1099, Ozenji, Aso-ku, Yokohama Stock Company Hitachi, Ltd. System Development Laboratory

Claims (6)

[Claims] 1. A network, a plurality of host computers connected to the network, and at least one network printer connected to the network, wherein the plurality of host computers share the network printer. In a remote printing system for printing, the host computer restarts communication with a memory for registering a connection state consisting of a communication partner and a host and a set of processes of itself and communication with the network printer after recovery from a communication failure. Communication resumption processing unit for
A non-volatile memory for registering the connection status of the network printer, which includes a communication partner, a host of itself, and a process, and a timer for monitoring the restart of communication; And a printer initialization processing unit that resumes communication with the network printer after recovery of communication failure, and when the communication failure occurs, the host computer displays information about the connection status registered in the memory. Originally, it waits for a communication start request from the network printer during communication, and the network printer communicates to the host computer based on the information about the connection state registered in the non-volatile memory during the printer initialization process. Request to start, restart the communication that was performed when the communication failure occurred, and continue printing. A remote printing system characterized in that 2. The host computer according to claim 1, wherein the host computer has a display device and an input device, and when the communication failure occurs, displays that the communication failure has occurred on the display device and continues printing from the input device. A remote printing system that performs communication restart processing when instructed to do so. 3. The host computer according to claim 1, wherein the host computer communicates with the network printer, which is in communication at the time of occurrence of a communication failure, at regular time intervals based on the information regarding the connection state registered in the memory. Request to start, the network printer
During the printer initialization process, based on the information related to the connection status registered in the non-volatile memory, waits for a communication start request from the host computer and restarts and continues the communication that was performed when the communication failure occurred. Remote printing system that prints by doing. 4. The remote printing system according to claim 1, wherein the host computer registers information regarding the connection status in the memory at the time of starting communication with the network printer. 5. The remote printing system according to claim 1, wherein the network printer registers information regarding the connection state in the non-volatile memory when communication with the host computer is started. 6. The host computer and the network printer according to claim 1, wherein a communication protocol used for communication between the computer requesting the printing and the network printer is at a time point when the communication is started. A remote printing system for registering information on the connection state in the memory and the non-volatile memory.