JP2007065797A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly notify a host computer about TRAP information even if trouble of a communication path occurs in TRAP transmission. <P>SOLUTION: This image forming device 2 is connected to a network 3, and is managed from the host computer 1 by an SNMP. A TRAP transmission part 24 transmits information related to an event generated inside the image forming device 2 to the host computer 1 by TRAP (the TRAP information). An ACK reception part 25 receives ACK returned from the host computer 1 to the TRAP. When the ACK is not returned from the host computer 1 after the TRAP transmission by the TRAP transmission part 24, the TRAP transmission is retried. When the ACK is not returned even after a prescribed retries, the TRAP information is stored and held in a storage part 23, and is transmitted after communication is restored. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus connected to a network and managed using an SNMP (Simple Network Management Protocol) service, and particularly when a predetermined event occurs during a printing process in the image forming apparatus. When the print processing is paused and TRAP is transmitted from the TRAP transmission unit, and then ACK is not received by the ACK reception unit, the image forming apparatus that repeatedly retryes TRAP transmission and retries a predetermined number of times. When the message is not received, the information on the event is stored and held, and after the communication is restored, the stored information on the event is transmitted to the host computer. .

  The SNMP service is widely used as a simple method for acquiring information of a device such as a printer in a TCP / IP network environment. This SNMP service has a function called TRAP. In this function, a device to be managed voluntarily notifies about a change in the state of the device based on a preset condition.

  SNMP is a network management protocol defined for collecting management information from nodes in the network, performing setting processing, and performing notification processing of events occurring in the nodes. A management station (such as a management server) The manager program in the computer apparatus) and the agent program in the managed node (device such as a printer) send and receive messages to and from each other.

  In a network management system using SNMP, management is generally performed by polling monitoring from a management station to a managed node. However, in polling monitoring, a request / response message flows on the network every time monitoring is performed, there is a problem that the network load increases when the number of nodes to be managed increases or the overhead of the management station increases. . Therefore, in order to realize management in real time, a process of transmitting TRAP to the management station only when an event such as a failure occurs in the managed node is executed. In this case, the TRAP transmission process is executed only once, and it is not checked at all whether it has reached the management station, and strict management cannot be performed.

  Therefore, when ACK (reception confirmation response) is not returned even though TRAP is transmitted, a system in which TRAP is repeatedly transmitted until ACK is returned as a retry process has been put into practical use. Such a network management system is also used for managing image forming apparatuses such as printers connected to the network.

  On the other hand, as shown in the following Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-355283), when an ACK is not returned from the host computer even though the TRAP is transmitted, it is the same as all the host computers on the network. There has also been proposed a technique in which an information TRAP is transmitted and a host computer that has received the information TRAP substitutes the information to a host computer that is the original destination of TRAP. By doing so, the TRAP information can be reliably notified to the host computer.

  That is, in the network management system disclosed in Patent Document 1, the managed node includes a TRAP transmission process, a TRAP management table having at least a TRAP destination MIB field and a reception response MIB field, and the terminal device receives TRAP. The TRAP reception process for setting the reception response information of the terminal device in the reception response MIB, and the broadcast TRAP is transmitted to the corresponding terminal device with reference to the TRAP destination MIB field when the broadcast TRAP is received. The TRAP transmission process stores the IP address of the TRAP destination terminal device in the TRAP destination MIB field and sets the reception response information in the reception response MIB field by the TRAP destination terminal device. If not Those that are configured to transmit the broadcast TRAP to each terminal device.

Japanese Unexamined Patent Publication No. 2004-355283 (FIGS. 2, 3, and 4)

  However, in the network management system that performs the above retry processing, if ACK is not returned due to a communication path failure, TRAP transmission retry is repeated. If the communication path failure continues for a long time, the printer There is a problem that the printing process is stopped and printing is delayed, and if ACK is not returned even after repeated retrying for a predetermined time, the information to be sent to the host computer must be finally discarded. There was a problem.

  In particular, by using such a network management system, information such as the number of pages of the job and the paper size is sent back to the host computer by TRAP at the end of the job or at each page discharge from the image forming apparatus, and the actual discharge base. In the case of charging management in the Internet, there is a problem that charging is lost if information is discarded.

  Further, in the above-described network management system that substitutes transmission from another host computer to the host computer that is the original destination of TRAP, the broadcast TRAP is received and held by all host computers on the network, and is transmitted by substitution. There was a problem that it was necessary to provide a function, and an extra burden was placed on the host computer.

  In view of such a problem, the present invention reliably notifies the TRAP information without imposing a burden on the host computer when the ACK is not returned for the TRAP transmission, and minimizes the stop period of the printing process. The purpose is to limit.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present application is
An image forming apparatus connected to a network and managed by SNMP from a host computer on the network,
A TRAP transmitting unit that transmits information about an event that has occurred in the image forming apparatus to the host computer by TRAP, and an ACK receiving unit that receives an ACK returned from the host computer to the TRAP,
When a predetermined event occurs during the printing process in the image forming apparatus, the printing process is temporarily stopped, the TRAP is transmitted from the TRAP transmitting unit, and then the ACK receiving unit does not receive the ACK, If TRAP transmission is retried repeatedly but no ACK is received after a predetermined number of retries, the TRAP information is stored and retained, and after the communication is restored, the TRAP information stored and retained is stored in the host computer. It is characterized by transmitting to.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect,
When the TRAP information is stored and held, the printing process that has been stopped after the occurrence of the event is resumed.

The image forming apparatus of the present invention has the following effects.
That is, in the invention according to claim 1 of the present application, when no ACK is returned after TRAP transmission, TRAP transmission is retried. When no ACK is returned even after a predetermined number of retries, TRAP information is stored and held. In addition, since the transmission is made to the host computer after the communication is recovered, the TRAP information can be surely notified to the host computer even if there is a failure in the communication path during the TRAP transmission.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the TRAP information is stored and held after retrying a predetermined number of times, the printing process that has been stopped after the occurrence of the event is immediately resumed. As a result, the print processing stoppage period can be minimized.

  Hereinafter, specific examples of the present invention will be described in detail with reference to examples and drawings.

  FIG. 2 is a diagram showing a schematic configuration of a network system according to the present invention. A plurality of host computers 1, 1, 1 and image forming apparatuses 2, 2 are connected to a network 3. The host computers 1, 1, 1 have a manager program for receiving TRAP in the SNMP management system in addition to the normal function of transmitting a job to the image forming apparatuses 2, 2. Run the receive process. The image forming apparatuses 2 and 2 are equipped with an agent program in the SNMP management system, and transmit events generated in the image forming apparatuses 2 and 2 to one of the corresponding host computers 1, 1, 1 as TRAP.

  FIG. 1 is a block diagram showing a schematic configuration of an image forming apparatus and a host computer of the present invention. The image forming apparatus 2 includes an interface unit 22 for transmitting and receiving information such as data and commands to and from the host computer 1 via the network 3 and a control unit 21. The control unit 21 is configured by a microprocessor, and the above agent program is mounted in addition to a control program for executing a printing process or the like, which is an original function of the image forming apparatus 2.

  The image forming apparatus 2 further includes a TRAP transmission unit 24, an ACK reception unit 25, a retry count unit 26, and a storage unit 23. The TRAP transmission unit 24 transmits an event generated in the image forming apparatus 2 as TRAP information, and the ACK reception unit 25 transmits the TRAP when the host computer 1 that transmitted TRAP receives the TRAP from the image forming apparatus 2. A reception confirmation signal (ACK) is received. The retry count unit 26 counts the number of times TRAP has been retransmitted (retries) when ACK cannot be received. When the number of retries reaches a predetermined number, the TRAP information is stored and held in the storage unit 23.

  The agent program includes a TRAP transmission command. This TRAP transmission command is a command for transmitting an event occurring in the image forming apparatus 2 as TRAP information to the host computer 1 of the print job transmission source. In the image forming apparatus 2, when the state / failure monitoring is executed and an event is detected, the TRAP transmission process is executed by this command. When the image forming apparatus 2 is in a state that matches a predefined TRAP transmission condition, the TRAP transmission unit 24 is operated by this agent program to execute a TRAP transmission command, and the specific host TRAP information is transmitted to the computer 1.

  The host computer 1 includes an interface unit 14 and a control unit 11 for transmitting and receiving information such as data and commands via the network 3. The control unit 11 is constituted by a microprocessor and includes the manager program in addition to a control program for executing normal functions, and the TRAP reception unit 12 executes a TRAP reception process. Further, a TRAP receiving unit 12 that receives TRAP transmitted from the image forming apparatus 1 and an ACK transmitting unit 13 that transmits ACK for confirming that TRAP has been received are provided.

  When the host computer 1 receives TRAP from the image forming apparatus 2, the ACK transmission unit 13 returns ACK to the image forming apparatus 2 for confirmation of reception. In the image forming apparatus 2, the ACK received from the host computer 1 is received by the ACK receiving unit 25, thereby confirming that the TRAP information has been received by the destination host computer 1.

  In such an image forming apparatus 2, when ACK is not returned after TRAP transmission due to a communication path failure or the like, the TRAP transmission unit 24 retries the TRAP transmission. At that time, the retry count unit 26 retries. Count the number of times. If no ACK is returned from the host computer 1 after retrying the TRAP transmission a predetermined number of times, the TRAP information is stored in the storage unit 23 and the printing process suspended for the TRAP transmission is resumed. To do. Thereafter, after the communication is recovered, it is transmitted to the host computer 1. As the storage unit 23, an appropriate storage device such as a RAM, NVRAM, HDD, flash memory or the like can be applied.

  Next, referring to the flowchart of FIG. 3, for each page discharge, information such as the number of pages and the paper size is sent back to the host computer by TRAP, and charging management is performed on an actual paper discharge basis. A TRAP transmission process of the image forming apparatus of the present invention will be described. When printing for one page is completed, the printing process is temporarily stopped, and the TRAP transmission unit 24 TRAP-transmits information such as paper size, color printing / monochrome printing, single-sided printing / double-sided printing, and the like to the host computer 1 (step). S1).

  Thereafter, the ACK receiving unit 25 determines whether or not an ACK is returned from the host computer 1 (step S2). If no ACK is returned even after a predetermined time has elapsed, the TRAP transmitting unit 24 transmits the TRAP. Is retried (step S3), and the retry count unit 26 adds 1 to the retry count CNT (step S4). Then, it is determined whether or not the number of retries CNT exceeds a predetermined number K set in advance (step S5). If the number of retries CNT does not exceed the predetermined number K, the process returns to step S2.

  If the retry count CNT exceeds the predetermined count K in step S5, the TRAP information to be transmitted is held in the storage unit 23 (step S6). Then, the temporarily stopped printing process is resumed. Then, after waiting for a certain time (step S7), it is determined whether or not communication with the host computer 1 has been recovered (step S8). If not recovered, the process returns to step S7 and waits for a certain time.

  When communication with the host computer 1 is restored in step S8, the TRAP information stored in the storage unit 23 is transmitted to the host computer 1 (step S9).

  As described above, in the present invention, when ACK is not returned after TRAP transmission, TRAP transmission is retried. When ACK is not returned even after a predetermined number of retries, TRAP information is stored and held. Since the transmission is made to the host computer after the communication is recovered, the TRAP information can be surely notified to the host computer even if there is a failure in the communication path during the TRAP transmission.

1 is a block diagram illustrating a schematic configuration of an image forming apparatus and a host computer according to the present invention. 1 is a diagram showing a schematic configuration of a network system according to the present invention. 6 is a flowchart showing TRAP transmission processing of the image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Host computer 11 ... Control part 12 ... TRAP receiving part 13 ... ACK transmission part 14 ... Interface part 2 ... Image forming apparatus 21 ... Control part 22 ... Interface part 23 ... Storage part 24 …… TRAP transmitter 25 …… ACK receiver 26 …… Retry count unit 3 …… Network

Claims (2)

An image forming apparatus connected to a network and managed by SNMP from a host computer on the network,
A TRAP transmitting unit that transmits information about an event that has occurred in the image forming apparatus to the host computer by TRAP, and an ACK receiving unit that receives an ACK returned from the host computer to the TRAP,
When a predetermined event occurs during the printing process in the image forming apparatus, the printing process is temporarily stopped, the TRAP information is transmitted from the TRAP transmitting unit, and then the ACK receiving unit does not receive the ACK. The TRAP transmission is retried repeatedly, but if the ACK is not received after a predetermined number of retries, the TRAP information is stored and retained, and after the communication is restored, the TRAP information stored and retained is stored in the host. An image forming apparatus that transmits the image to a computer.   The image forming apparatus according to claim 1, wherein when the TRAP information is stored and held, the printing process that has been stopped after the occurrence of the event is resumed.

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