JP2004364190A - Communication apparatus and program for realizing the apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of a conventional communication apparatus that cannot make communication with a communication object apparatus when identification information of the communication object apparatus in a network is dynamically changed. <P>SOLUTION: The communication apparatus 100 stores an IP address and a MAC address of the communication object apparatus 50 in cross-reference with each other. When the communication apparatus 100 makes communication with the communication object apparatus 50, first the communication apparatus 100 utilizes the IP address having been stored in the communication apparatus 100 to connect with the communication object apparatus 50. Then the communication apparatus 100 compares a MAC address of the connected communication object apparatus 50 with the MAC address having been stored in the communication apparatus 100 and decides whether or not the MAC addresses are coincident. When they are coincident, the communication apparatus 100 transmits data to the communication object apparatus 50. Further, when they are not coincident, the communication apparatus 100 acquires a new IP address of the communication object apparatus 50 to try again to make communication. Thus, even when the IP address is dynamically assigned to the communication object apparatus 50, the communication apparatus 100 can make communication with the communication object apparatus 50. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to communication technology, and particularly to communication technology with a device to which dynamically changing identification information is assigned.
[0002]
[Prior art]
With the development of network technology, devices that are connected to a network such as a LAN (Local Area Network) or a WAN (Wide Area Network) and are configured to be able to communicate with each other have become widespread. The device is, for example, a printer, facsimile, scanner, or the like, and can be used from a client device connected to a network. These devices are assigned identification information such as an IP (Internet Protocol) address or a MAC (Media Access Control) address that uniquely identifies the device on the network, and the client device uses the identification information to perform network communication. A device to be used is specified from among the devices existing above, and a predetermined operation instruction is transmitted. For example, as a method of assigning an IP address, which is one of the identification information, there are a method of assigning a fixed address to each device and a method of dynamically assigning the address by using a DHCP (Dynamic Host Configuration Protocol).
[0003]
Generally, an IP address is assigned to a device such as a client device whose connection status to a network is apt to change using DHCP, and a fixed IP address is assigned to a printer, facsimile, scanner, or the like having a fixed connection status. . If the device to which the IP address is dynamically assigned and the device to which the fixed IP address is assigned are present in the same network, the range of the IP address assigned by DHCP is appropriately adjusted so that the IP address does not overlap. You need to decide. In order to solve such an operation, there is a technology that enables a client device to grasp an IP address assigned to a printer and perform printing even when an IP address is assigned to the printer using DHCP. (Patent Document 1)
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-222149
[Problems to be solved by the invention]
In the technique disclosed in Patent Document 1, it is necessary to constantly monitor the network, so that, for example, when the power of the client device is turned off, it is not possible to detect that the IP address of the printer has been changed. Also, since the signal for requesting the DHCP server to assign an IP address does not include information for specifying the type of the device that has transmitted the signal, the request may be transmitted from the printer or may be a mere other client device. It is not possible to specify whether the request was sent. In general, the client device has a program that uses the IP address of the printer for processing, and when the IP address is changed, it is necessary to update related information used by such a program. However, since the disclosed technology does not update the related information, it is necessary for the user himself to update the related information.
[0006]
The present invention has been made in view of such a point, and an object of the present invention is to enable communication with a device to be communicated even when identification information of the device to be dynamically changed in the network and to enable application in a client device. It is an object of the present invention to provide a technique for appropriately updating setting information of a program and setting information of a client device itself.
[0007]
[Means for Solving the Problems]
One embodiment of the present invention relates to a communication device. This device holds holding means for associating first identification information dynamically assigned to a predetermined device connected to a network with second identification information statically assigned to the predetermined device. And identification information statically assigned to the device connected using the first identification information, and second identification information associated with the first identification information held in the holding unit. And a means for transmitting predetermined information to the apparatus when they match. Thus, it is possible to perform communication after confirming that the device to be communicated to which the first identification information is dynamically assigned is the original communication target by the second identification information. The “first identification information” is, for example, an IP address dynamically assigned by DHCP. The “second identification information” is, for example, a MAC address preset in a LAN card or the like.
[0008]
When the apparatus cannot connect to the predetermined apparatus by using the first identification information, the predetermined identification information assigned with the second identification information associated with the first identification information held in the holding unit is provided. Means for retrieving the device from the network again to obtain the newly assigned first identification information; and adding the first identification information associated with the second identification information to the obtained first identification information. Rewriting means may be further provided. Thereby, even when the first identification information is changed, it is possible to acquire the newly assigned first identification information.
[0009]
Another embodiment of the present invention relates to a communication device. The apparatus includes means for associating first identification information dynamically assigned to a predetermined device connected to a network with second identification information statically assigned to the predetermined device, and Means for storing processing location information for specifying a location for storing the first identification information as setting information, wherein the program for performing processing for a predetermined device using the first identification information includes: Means for rewriting the setting information stored in the location specified by the storage location information with new first identification information when the associated first identification information changes. As a result, the first identification information held as the setting information is constantly updated, so that the configuration realized by executing a predetermined program using the first identification information is different from the original communication target. Communication can be performed without recognizing that the first identification information of the device to be changed has changed. That is, it is possible to avoid a situation in which communication cannot be performed due to a change in the first identification information.
[0010]
It is to be noted that any combination of the above-described components and any conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, and the like are also effective as embodiments of the present invention.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a configuration diagram of a communication system 10 according to the embodiment. The DHCP server 12 assigns an IP address to a device on the network 14 that has requested the assignment of the IP address. The communication target device 50 may be, for example, a printer, a scanner device, an MFP (Multi Functional Peripheral), a facsimile device, a document management device, a file server, or the like, and may be a predetermined device according to an instruction from the communication device 100 connected to the network 14. Is performed. In the present embodiment, a case where the communication target device 50 is a facsimile device will be described as an example. The communication target device 50 uses an IP address dynamically allocated to the DHCP server 12 and a MAC address statically allocated to perform communication with a device connected to the network 14. The MAC address is, for example, information preset in a network card or the like for connecting the communication target device 50 to the network 14, and is always uniquely specified in a WAN. That is, each device can be specified by the MAC address. In another example, the identification information statically assigned to the communication target device 50 may be a name unique to the device.
[0012]
The communication device 100 is a client device that uses the communication target device 50, and transmits information such as a command for an operation instruction to an IP address assigned to the communication target device 50. In order to obtain the IP address, the communication device 100 broadcasts a signal (hereinafter, simply referred to as a “request signal”) requesting the communication target device 50 to notify the IP address to the network 14. The request signal is transmitted to all devices connected to the network 14 by the broadcast. The request signal is, for example, a signal addressed to a predetermined port including a predetermined character string.
[0013]
When receiving the request signal, the response unit 52 transmits device information such as a name, an IP address, and a MAC address assigned to the communication target device 50 to the communication device 100. The data format of the request signal for the response unit 52 to transmit the device information is predetermined, and only the device having the response unit 52 corresponding to the data format transmits the device information to the communication device 100. Thereby, the communication device 100 can grasp the IP address of the communication target device 50 connected to the network 14, and can communicate with the communication target device 50 using the IP address. Although details will be described later, performing such processing for each communication is inefficient, so the communication device 100 holds the obtained device information and performs communication using the held IP address. Then, when the IP address of the communication target device 50 is changed and communication becomes impossible, when the power of the communication device 100 is turned on, or when a predetermined period elapses, the communication device 100 starts communication on the network 14 again. The target device 50 is searched to obtain device information.
[0014]
FIG. 2 is an internal configuration diagram of the communication device 100 of FIG. Each component of the communication device 100 is, in terms of hardware components, a CPU of an arbitrary computer, a memory, a program for realizing the components of the drawing loaded in the memory, a storage unit such as a hard disk for storing the program, It is realized mainly by an interface for network connection, a modem for facsimile communication, and the like, and it will be understood by those skilled in the art that there are various modifications in the method and apparatus for realizing the method. Each of the drawings to be described below shows a block of a functional unit, not a configuration of a hardware unit.
[0015]
The initial search unit 102 is a functional block for searching for the communication target device 50 connected to the network 14 and storing device information of the communication target device 50 whose presence has been detected in the identification information storage unit 116. The search data storage unit 104 holds data used for the search, that is, data such as a character string included in the request signal. Transmitting section 106 broadcasts the data to network 14 as a request signal. The receiving unit 108 receives a response signal of the communication target device 50 to the request signal. The extracting unit 110 extracts device information such as the name, the IP address, and the MAC address of the communication target device 50 from the response signal. For example, the device information is included in the response signal in a predetermined order separated by a predetermined delimiter, and the extraction unit 110 may extract the device information in each order or provide the device information as an XML format file. Device information may be extracted from the response signal to be transmitted. When a plurality of communication target devices 50 are connected to the network 14, the receiving unit 108 receives a plurality of response signals, and the extracting unit 110 extracts device information for each of the response signals.
[0016]
The selection unit 112 selects device information to be stored in the identification information storage unit 116 from among the plurality of communication target devices 50 that have returned the response signal. That is, the selection unit 112 selects the communication target device 50 used by the communication device 100 from among the communication target devices 50 connected to the network 14, and stores the device information of the selected communication target device 50 in the identification information storage unit. 116. For this selection, the selection unit 112 displays a list of all the communication target devices 50 that have returned the response signal, and allows the user to select a communication target device 50 to be used from the list. Further, as another example, when the device information includes the installation location information regarding the installation location of the communication target device 50, the selecting unit 112 uses the installation location information to perform communication with the communication device 100 close to the communication device 100. The device 50 may be automatically selected. The installation location information is, for example, a building, a floor, a room, a department, or the like where the device is installed, and the selection unit 112 selects a communication target device 50 in which the same installation location information is set. In addition, the installation location information is formed so that the installation location can be specified stepwise from a wide range to a narrow range, and when a device is not found in the narrow range, the selection unit 112 gradually widens the range to select the communication device 100. May be selected. For example, as installation location information, a building, a floor, and a room are set in order from a wide range to a narrow range. Then, the selection unit 112 first searches for the communication target device 50 in the same room, and if not, searches for the communication target device 50 on the same floor. The selection unit 112 performs this processing until the communication target device 50 is found. Thereby, the selection unit 112 can automatically select the communication target device 50 closest to the communication device 100.
[0017]
FIG. 3 is a diagram illustrating an example of a data structure of the identification information storage unit 116 in FIG. The name column 150 holds the name of the communication target device 50. The IP address column 152 holds an IP address dynamically assigned to the communication target device 50. The MAC address column 154 holds a MAC address statically assigned to the communication target device 50. In the related setting information column 156, information for specifying a storage location such as a file name or a URI (Uniform Resource Identifiers) of a file that stores the IP address as setting information by a program that uses the IP address of the communication target device 50 for processing is stored. Hold. The purpose of using the information held in the related setting information column 156 will be described later.
[0018]
Returning to FIG. 2, the re-search unit 114 searches again for the communication target device 50 connected to the network 14, and searches for the IP address currently assigned to the communication target device 50 held in the identification information storage unit 116. It is determined whether the IP address stored in the identification information storage unit 116 matches. The internal configuration of the re-search unit 114 may be substantially the same as the initial search unit 102, for example. The re-search unit 114 extracts the IP address extracted from the response signal including the MAC address that matches the MAC address of the communication target device 50 to be re-searched, the IP address held in the identification information storage unit 116, It is determined whether or not matches. If they do not match, the re-search unit 114 rewrites the IP address held in the identification information storage unit 116 with a new IP address. Thus, when the IP address of the communication target device 50 is changed, the IP address stored in the identification information storage unit 116 can be rewritten.
[0019]
For example, when the re-searching unit 114 cannot connect to the communication target device 50 with the IP address stored in the identification information storage unit 116, the IP address stored in the identification information storage unit 116 is assigned. This may be when the IP address is assigned to a device different from the communication target device 50 to be set, when the power of the communication device 100 is turned on, or when a preset period has elapsed. These timings will be described in detail in connection with the description of the functional blocks described later.
[0020]
The application processing unit 122 is realized by executing a program that uses the communication target device 50, and is, for example, a web browser, various drivers, an application for operating the communication target device 50, and the like. The setting information storage unit 120 holds setting information used by these programs, and holds, for example, the IP address of the communication target device 50 as setting information. Each program executed by the application processing unit 122 communicates with the communication target device 50 via the communication unit 124 using an IP address held as setting information in the setting information storage unit 120.
[0021]
For example, when the application processing unit 122 implements the function of a web browser, the setting information storage unit 120 may be a shortcut to the URL of the communication target device 50 displayed on the desktop screen of the communication device 100. Generally, the communication target device 50 provides an interface for operation using a web page. Therefore, in order to facilitate access to the web page, the URL of the web page is registered in a bookmark or a shortcut is stored in the client device. The setting information storage unit 120 indicates an area for holding such information.
[0022]
The update unit 118 updates related setting information held in the setting information storage unit 120 when a change occurs in the identification information storage unit 116. For example, when the setting information storage unit 120 is a web page shortcut, the update unit 118 changes the URL set in the shortcut to a new IP address. The information held in the related setting information column 156 described with reference to FIG. 3 indicates a storage location of the setting information, and the update unit 118 specifies the setting information to be updated using the information. . The update unit 118 may grasp the position of data to be rewritten for each type of setting information, or may detect an IP address included in the setting information and rewrite the IP address with a new IP address. . Thus, the setting information stored in the setting information storage unit 120 is constantly updated in the same manner as the IP address stored in the identification information storage unit 116.
[0023]
The communication unit 124 transmits a communication packet with the IP address included in the setting information as a destination. In another example, the communication unit 124 may directly use the IP address stored in the identification information storage unit 116. If the IP address of the communication target device 50 has been changed, the power of the communication target device 50 has been turned off, or the communication target device 50 has been disconnected from the network 14, the communication unit 50 cannot be connected. 124 requests the re-search unit 114 to search for the communication target device 50. If the communication target device 50 cannot be connected despite the re-search, the notifying unit 128 notifies the communication target device 50 that the communication target device 50 is powered off or disconnected from the network 14. It is determined that the error has occurred at 50 and the user is notified of that fact. For example, the notifying unit 128 may display a pop-up screen on the monitor to notify, or may notify by a buzzer, sound, or the like.
[0024]
Here, even if a device on the network 14 can be connected based on the IP address, the device is not necessarily a desired communication target device 50. That is, the IP address held in the identification information storage unit 116 may be newly assigned to another communication device 100 on the network 14 or a device other than the desired communication target device 50 in some cases. If the user instructs the communication target device 50, which is a facsimile device, to transmit a facsimile, if an IP address is assigned to a device other than the facsimile device, an error occurs and the process can be interrupted. However, if the IP address is assigned to a facsimile apparatus different from the facsimile apparatus desired by the user, facsimile transmission is performed without any error. This is an unexpected operation for the user, and for example, the user may not be able to grasp from which facsimile device the facsimile device was transmitted despite facsimile transmission being performed.
[0025]
Therefore, after confirming that the connected communication target device 50 is the desired device, the confirmation unit 126 instructs the communication unit 124 to transmit data. For this confirmation, the confirmation unit 126 uses the MAC address held in the identification information storage unit 116. Generally, a communication packet includes a source MAC address. The confirmation unit 126 compares the MAC address with the MAC address held in the identification information storage unit 116, and when the MAC address matches, the desired device, that is, the device held in the identification information storage unit 116 It is determined that they are the same, and the communication unit 124 is allowed to transmit data. If they do not match, the confirmation unit 126 instructs the re-search unit 114 to perform a re-search. This can prevent data from being transmitted to a device other than the desired device.
[0026]
The initial search unit 102 is a configuration for initially registering device information in the identification information storage unit 116, and may be realized, for example, when installing a program for transmitting an operation instruction to the communication target device 50. At the time of this installation, setting information used by the program is stored in the setting information storage unit 120, and information on the storage location is stored in the related setting information column 156 of the identification information storage unit 116.
[0027]
FIG. 4 is a diagram showing an example of a flowchart at the time of communication in the communication device 100 of FIG. First, the communication unit 124 in FIG. 2 requests a connection to the communication target device 50 specified by the setting information stored in the setting information storage unit 120, that is, the IP address stored in the identification information storage unit 116 ( S10). If the connection can be established by the request (Y in S12), the confirmation unit 126 determines whether or not the connected device is the same device as the device held in the identification information storage unit 116 (S14). In the case of the same device (Y in S14), the confirmation unit 126 permits data transmission, and the communication unit 124 transmits data (S16).
[0028]
If it is not possible to connect to the communication target device 50 in step 12 (N in S12), and if it is not the same device in step 14 (N in S14), the re-search unit 114 performs a re-search (S18). Then, when the communication target device 50 to which the new IP address is assigned can be searched (Y in S20), the re-search unit 114 writes the new IP address into the identification information storage unit 116, and the update unit 118 sets the setting information The IP address stored in the storage unit 120 is updated to a new IP address (S24). If it is determined in step 20 that the communication target device 50 cannot be searched (N in S20), the notification unit 128 notifies the user to that effect (S22).
[0029]
The present invention has been described based on the embodiments. It should be understood by those skilled in the art that the embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. . In the embodiment, the IP address is exemplified as the identification information dynamically assigned to the communication target device 50, and the MAC address is exemplified as the identification information assigned statically. However, other examples are not limited thereto.
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, even if the identification information dynamically allocated to the communication target apparatus changes, it can communicate with that apparatus.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a communication system according to an embodiment.
FIG. 2 is an internal configuration diagram of the communication device of FIG. 1;
FIG. 3 is a diagram illustrating an example of a data structure of an identification information storage unit in FIG. 2;
4 is a diagram illustrating an example of a flowchart at the time of communication in the communication device of FIG. 2;
[Explanation of symbols]
Reference Signs List 10 communication system, 50 communication target device, 52 response unit, 100 communication device, 102 initial search unit, 104 search data storage unit, 106 transmission unit, 108 reception unit, 110 extraction unit, 112 selection unit, 114 re-search unit, 116 identification information storage unit, 118 update unit, 120 setting information storage unit, 122 application processing unit, 124 communication unit, 126 confirmation unit, 128 notification unit.

Claims (4)

Holding means for holding first identification information dynamically assigned to a predetermined device connected to a network and second identification information statically assigned to the predetermined device in association with each other;
Identification information statically assigned to a device connected using the first identification information, and the second identification information associated with the first identification information held in the holding unit Means for determining whether or not
Means for transmitting predetermined information to the device if they match,
A communication device comprising: If it is not possible to connect to the predetermined device using the first identification information, the second identification information associated with the first identification information held in the holding means is assigned. Means for retrieving a predetermined device from the network again to obtain newly assigned first identification information;
Means for rewriting the first identification information associated with the second identification information with the acquired first identification information;
The communication device according to claim 1, further comprising: Means for associating first identification information dynamically assigned to a predetermined device connected to the network with second identification information statically assigned to the predetermined device,
Means for storing a storage location information for specifying a location where the first identification information is stored as setting information, wherein the program for performing processing on the predetermined device using the first identification information;
Means for rewriting the setting information stored in the location specified by the storage location information to new first identification information when the first identification information associated with the second identification information changes When,
A communication device comprising: On the computer,
Holding means for holding first identification information dynamically assigned to a predetermined device connected to a network and second identification information statically assigned to the predetermined device in association with each other;
Identification information statically assigned to a device connected using the first identification information, and the second identification information associated with the first identification information held in the holding unit Means for determining whether or not
Means for transmitting predetermined information to the device if they match,
The program to realize.

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