Patent Publication Number: US-2015081889-A1

Title: Information processing apparatus, device management system and device management method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2013-191885 filed in Japan on Sep. 17, 2013. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an information processing apparatus, a device management system, and a device management method. 
     2. Description of the Related Art 
     A device management apparatus is conventionally known which manages a device connected through a network. For example, Japanese Patent No. 3937478 discloses a technology for using a network expansion board having agents for various protocols to connect the devices to be managed with the network, and exchanging management information between processing modules and the devices to be managed using the protocols. 
     Some device management apparatuses are configured to manage a device through an information processing apparatus such as a personal computer (PC) connected through a network. The device herein is connected to the information processing apparatus through a communication interface, such as a universal serial bus (USB) cable. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to an aspect of the present invention, there is provided an information processing apparatus that is configured to communicate with a device through a first communication path and to communicate, through a second communication path, with a device management apparatus configured to manage the device, the information processing apparatus including: a detection part configured to detect connection with the device through the first communication path; a transmission part configured to transmit predetermined notification including identification information of the information processing apparatus to the device management apparatus when the connection with the device is detected; a reception part configured to receive a device information acquisition request from the device management apparatus based on the predetermined notification; and an acquisition part configured to acquire device information of the device based on the device information acquisition request, wherein the transmission part transmits, to the device management apparatus, response to acquisition of the device information including the identification information of the information processing apparatus and the device information of the device. The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating an exemplary configuration of a device management system according to the present embodiment; 
         FIG. 2  is a block diagram illustrating an exemplary configuration of the device management system according to the present embodiment; 
         FIG. 3  is a block diagram illustrating an exemplary configuration of a PC according to the present embodiment; 
         FIG. 4  is a view of exemplary response data according to the present embodiment; 
         FIG. 5  is a view of exemplary response data according to the present embodiment; 
         FIG. 6  is a block diagram illustrating an exemplary configuration of a device according to the present embodiment; 
         FIG. 7  is a block diagram illustrating an exemplary configuration of a device management apparatus according to the present embodiment; 
         FIG. 8  is a table illustrating an example of device information stored in a storage unit by a controller according to the present embodiment; 
         FIG. 9  is a table illustrating an example of the device information stored in the storage unit by the controller according to the present embodiment; 
         FIG. 10  is a flowchart illustrating exemplary processing performed when the PC detects the connection of the device in the device management system according to the present embodiment; 
         FIG. 11  is a flowchart illustrating exemplary processing performed when the PC detects the disconnection of the device in the device management system according to the present embodiment; 
         FIG. 12  is a flowchart illustrating exemplary protocol determination of the device management apparatus according to the present embodiment; 
         FIG. 13  is a flowchart illustrating exemplary determination of a protocol conversion module for the PC according to the present embodiment; 
         FIG. 14  is a table illustrating exemplary device information stored in a storage unit by a controller according to a modification; 
         FIG. 15  is a view of exemplary response data according to a modification; 
         FIG. 16  is a view of exemplary response data according to a modification; 
         FIG. 17  is a block diagram illustrating an exemplary hardware configuration of the PC and the device management apparatus according to the present embodiment; and 
         FIG. 18  is a block diagram illustrating an exemplary configuration of a device according to a modification. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of an information processing apparatus, a device management system, a program, and a device management method according to the present invention will be described below in detail with reference to the accompanying drawings. 
       FIGS. 1 and 2  are block diagrams illustrating exemplary configurations of the device management system  1  according to the present embodiment. As illustrated in  FIG. 1 , the device management system  1  includes personal computers (PC)  10  and  11  (an example of information processing apparatus), devices  20  and  21 , and a device management apparatus  30 . The PCs  10  and  11 , the device  21 , and the device management apparatus  30  are connected to one another through a network  2  (an example of second communication path). 
     The device  20  can be connected to the PC  10  through a communication interface  3  (an example of first communication path) as illustrated in  FIG. 1 , the device can be connected to the PC  11  through the communication interface  3  as illustrated in  FIG. 2 , or the device can be connected to the device management apparatus  30  through the network  2 , though not illustrated in the figures. 
     That is, in the device management system  1  according to the present embodiment, at least connection of the device  20  can be locally switched between the PCs through the communication interface  3 . Further, the connection can be switched to network connection for the connection to the network  2 . 
     The network  2  includes the Internet, a local area network (LAN), or the like. The communication interface  3  includes a universal serial bus (USB) cable or the like. 
     The device management apparatus  30  is provided at a service center of a service provider that provides a device management service, and the PCs  10  and  11  and the devices  20  and  21  are provided at service points. The service point is in an area in which a device to be managed is installed. The service point includes, for example, a business office receiving the device management service. It is noted that an installation place of the device management apparatus  30  is not limited to the service center, and the service point or the like may be employed as the installation place. 
     The device management apparatus  30  is configured to manage the PCs  10  and  11  and the devices  20  and  21 , and includes a PC installed with a device management (manager) program which will be described below, or the like. It is obvious that, in  FIGS. 1 and 2 , the PCs  10  and  11  and the devices  20  and  21  are illustrated as the devices to be managed by the device management apparatus  30 , but the device to be managed by the device management apparatus  30  is not to be limited to them. 
     The PCs  10  and  11  are installed with an agent program which will be described below. As illustrated in  FIGS. 1 and 2 , while the device  20  is connected through the communication interface  3 , when acquisition of device information is requested from the device management apparatus  30 , the device information is acquired from the device  20  through the communication interface  3 , and the device management apparatus  30  is notified of the device information. Therefore, the device management apparatus  30  can manage the device  20  even if the device  20  is not connected to the network  2 . 
     The device  20  is preferably a device connectable to both of the communication interface  3  and the network  2 , and the device  21  is preferably a device connectable to at least the network  2 . It is noted that the device  21  may also be connectable to both of the communication interface  3  and the network  2 . 
     Examples of the devices  20  and  21  include an image forming apparatus such as a printer, a copier, a multifunction peripheral, a scanner, and a facsimile machine as well as various electronic devices such as a projector, a camera, an air conditioner, a refrigerator, a fluorescent lamp, an automatic dispenser, and a hand-held terminal. The multifunction peripheral (MFP) has at least two of a copy function, a print function, a scanner function, and a facsimile function. It is noted that in the present embodiment, the devices  20  and  21  will be described as an example of a projector. 
     It is noted that in the following description, the device connected to the network  2  is sometimes referred to as a network device, and the device connected to the communication interface  3  is sometimes referred to as a local device. 
       FIG. 3  is a block diagram illustrating an exemplary configuration of the PCs  10  and  11  according to the present embodiment. As illustrated in  FIG. 3 , the PCs  10  and  11  each include a communication unit  111 , a communication unit  112 , an operating unit  120 , a display unit  130 , a storage unit  140 , and a controller  150 . 
     The communication unit  111  is configured to communicate with an external apparatus such as the device management apparatus  30  through the network  2 , and includes a network interface card (NIC) or the like. 
     The communication unit  112  communicates with a local device such as the device  20  through the communication interface  3  and includes a USB or the like. 
     The operating unit  120  is configured to perform various operation inputs, and includes an input device such as a keyboard, a mouse, a touch pad, and a touch panel. 
     The display unit  130  is configured to display various screens, and includes a display device such as a liquid crystal display and a touch panel display. 
     The storage unit  140  is configured to store various programs, data, or the like. The various programs include an operating system (OS) program and an agent program which are executed on the PCs  10  and  11 . The data is used for various processing performed on the PCs  10  and  11 . The storage unit  140  includes at least one of storage devices for magnetic, optical, and electrical storage, for example, a hard disk drive (HDD), a solid state drive (SSD), a memory card, an optical disk, a read only memory (ROM), and a random access memory (RAM). 
     The storage unit  140  includes a device information storage unit  141  for storing device information of the PCs  10  and  11 , and device information of the local device. The device information storage unit  141  stores the device information of the PCs  10  and  11  beforehand, and stores device information of the local device at any time by a controller  150  described below when the local device is connected to the PC. 
     The device information of the PCs  10  and  11  is preferably information relating to the PCs  10  and  11 , for example, serial numbers, IP addresses, MAC addresses, machine names, model names, administrator information, and error information of the PCs  10  and  11 . The device information of the local device is preferably information relating to the local device, for example, a serial number, MAC address, machine name, model name, counter information, and error information (call information) of the local device. 
     The controller  150  is configured to control each unit of the PCs  10  and  11 , and includes a control device such as a central processing unit (CPU). The controller  150  includes OS software  160  and agent software  170 . The controller  150  runs (executes) the OS program and the agent program stored in the storage unit  140  in order to effect the OS software  160  and the agent software  170 . 
     The OS software  160  is configured to control each unit of the PCs  10  and  11  (in particular, hardware and software of PCs  10  and  11 ), and includes basic software, for example, Windows (registered trademark) or UNIX (registered trademark). The OS software  160  includes a transmission part  161 , a reception part  162 , and a generation part  163 . It is noted that the transmission part  161 , the reception part  162 , and the generation part  163  will be described appropriately. 
     The agent software  170  is configured to acquire device information from the local device. The agent software includes a detection part  171 , a protocol determination module  172 , and a first protocol conversion module  180  to an n-th (n is a natural number) protocol conversion module  190 . 
     The detection part  171  detects connection with or disconnection from the local device through the communication interface  3 . 
     When connection with the local device is detected by the detection part  171 , the transmission part  161  transmits predetermined notification including identification information of the PCs  10  and  11  to the device management apparatus  30 . Further, when the disconnection from the local device is detected by the detection part  171 , the transmission part  161  transmits the predetermined notification including the identification information of the PCs  10  and  11  to the device management apparatus  30 . 
     For example, the transmission part  161  transmits a TRAP of the simple network management protocol (SNMP) as the predetermined notification to the device management apparatus  30 . The identification information of the PCs  10  and  11  preferably includes at least the IP addresses of the PCs  10  and  11 . 
     The reception part  162  receives a device information acquisition request from the device management apparatus  30  based on the predetermined notification. The reception part  162  preferably makes communication using a protocol for communication with the device management apparatus  30 . The protocol includes, for example, the SNMP, the hypertext transfer protocol (HTTP), and the simple object access protocol (SOAP). 
     When the connection with the local device is detected by the detection part  171 , the protocol determination module  172  determines a protocol to which the protocol of the device information acquisition request received by the reception part  162  is to be converted. More specifically, the protocol determination module  172  causes the first protocol conversion module  180  to the n-th protocol conversion module  190  (an example of acquisition part) to perform a test communication with the local device. Then, the converted protocol of the device information acquisition request is determined as the protocol conversion module having been used for the test communication in which response has been received from the local device. 
     It is noted that when the disconnection from the local device is detected by the detection part  171 , the protocol determination module  172  cannot communicate with the local device, so that the converted protocol of the device information acquisition request received by the reception part  162  is not determined. 
     The first protocol conversion module  180  to the n-th protocol conversion module  190  are modules each corresponding to the converted protocol of the device information acquisition request. The protocol conversion module determined by the protocol determination module  172  converts the device information acquisition request to a device information acquisition request for a protocol of itself, communication is performed with the local device, and the device information of the local device is acquired. 
     The protocol conversion module converts the acquired device information of the local device to a protocol for a response to acquisition of the device information, acquires the IP addresses and MAC addresses of the PCs  10  and  11  from the device information storage unit  141 , and generates the response to acquisition of the device information including the IP addresses and MAC addresses of the PCs  10  and  11 , and the converted device information of the local device. 
     It is noted that when the device information of the local device is acquired from periodical processing, the protocol conversion module converts the acquired device information of the local device for the protocol for response to acquisition of the device information to be stored in the device information storage unit  141 . 
     For example, the protocol conversion module formats the acquired device information of the local device in XML data as illustrated in  FIG. 4 , parses data of a “statuses” tab of the formatted XML data, and converts the parsed data for a protocol (XML) for the response to acquisition of the device information. It is noted that the protocol conversion module may format the acquired device information of the local device in MIB data as illustrated in  FIG. 5 , and may convert the formatted MIB data for the protocol (SNMP) for the response to acquisition of the device information. 
     The device information of the local device will be described below to include a serial number and counter information of the local device, or status information such as error information, but it is considered that the device information is not limited to such a configuration. 
     When the connection with the local device is detected by the detection part  171 , the transmission part  161  transmits the response to acquisition of the device information which has been generated by the protocol conversion module to the device management apparatus  30 . 
     On the other hand, when the disconnection from the local device is detected by the detection part  171 , the generation part  163  acquires the IP addresses and MAC addresses of the PCs  10  and  11 , and the device information of the local device from the device information storage unit  141  to generate the response to acquisition of the device information, and the transmission part  161  transmits the response to acquisition of the device information to the device management apparatus  30 . 
       FIG. 6  is a block diagram illustrating an exemplary configuration of the device  20  according to the present embodiment. As illustrated in  FIG. 6 , the device  20  includes a communication unit  210 , a communication unit  211 , an operating unit  220 , a display unit  230 , a storage unit  240 , a controller  250 , and a projection unit  260 . 
     The communication unit  210  is configured to communicate with the external apparatus such as the device management apparatus  30  through the network  2 , and includes an NIC or the like. 
     The communication unit  211  is configured to communicate with the PCs  10  and  11  through the communication interface  3 , and includes a USB or the like. 
     The operating unit  220  is configured to perform various operation inputs, and includes an input device such as a key switch and a touch panel. 
     The display unit  230  is configured to display various screens, and includes a display device such as a liquid crystal display or a touch panel display. 
     The storage unit  240  stores various programs, data, or the like. The various programs are executed in the device  20 . The data is used for various processing performed in the device  20 , such as device information of the device  20 . The device information of the device  20  is preferably information relating to the device  20 , for example, a serial number, an IP address, a MAC address, a machine name, a model name, counter information and error information (call information) of the device  20 . However, when the device  20  is connected to the network  2 , or when the device  20  is a network device, the IP address is stored in the storage unit  240  as the device information. 
     The controller  250  is configured to control each unit of the device  20 , and includes a control device such as a CPU. 
     When the device  20  is connected to the communication interface  3 , the controller  250  transmits the device information to the PCs  10  and  11  through the communication interface  3 , upon reception of the device information acquisition request from the PCs  10  and  11  through the communication interface  3 . Further, when an error occurs in the device  20 , the controller  250  generates the device information to be transmitted to the PCs  10  and  11  through the communication interface  3 . 
     When projection is requested from the PCs  10  and  11  using PJL, the projection unit  260  performs projection. 
       FIG. 7  is a block diagram illustrating an exemplary configuration of the device management apparatus  30  according to the present embodiment. As illustrated in  FIG. 7 , the device management apparatus  30  includes a communication unit  310 , an operating unit  320 , a display unit  330 , a storage unit  340 , and a controller  350 . 
     The communication unit  310  is configured to communicate with a network device such as the PCs  10 ,  11  or the devices  20 ,  21  through the network  2 , and includes an NIC or the like. 
     The operating unit  320  is configured to perform various operation inputs, and includes the input device such as a keyboard, a mouse, a touch pad, and a touch panel. 
     The display unit  330  is configured to display various screens, and includes a display device such as a liquid crystal display or a touch panel display. 
     The storage unit  340  stores various programs, data, or the like. The various programs include a device management program executed in the device management apparatus  30 . The data is used for various processing performed in the device management apparatus  30 . The storage unit  340  includes at least one of storage devices for magnetic, optical, and electrical storage, for example, an HDD, an SSD, a memory card, an optical disk, a ROM, and a RAM. The storage unit  340  stores the device information of the device to be managed by the device management apparatus  30 , such as the PCs  10  and  11  or the devices  20  and  21 . 
     The controller  350  is configured to control each unit of the device management apparatus  30 , and includes a control device such as a CPU. The controller  350  functions as device management software, and also functions as a manager to the agent software  170  of the PCs  10  and  11 . 
     The controller  350  transmits the device information acquisition request to the PC 10  or PC 11  based on predetermined notification from the PC 10  or PC 11 . The controller associates the identification information of the PC 10  or PC 11  with the device information of the local device. The identification information and the device information are included in the response to acquisition of the device information from the PC  10  or PC  11 . The associated information is managed on the storage unit  340 . 
     When the device information acquisition request is sent to the PC 10  or the PC 11 , the controller  350  makes test communication with the PC  10  or the PC  11  using various protocols such as SNMP, HTTP, or SOAP. The device information acquisition request is sent to the PC  10  or the PC  11  using the protocol having been used for the test communication through which response has been received from the PC  10  or the PC  11 . 
       FIGS. 8 and 9  are tables illustrating examples of the device information stored in the storage unit  340  by the controller  350  according to the present embodiment.  FIG. 8  illustrates the device information of the devices being connected as illustrated in  FIG. 1 .  FIG. 9  illustrates the device information of the devices being connected as illustrated in  FIG. 2  after switching from the connection illustrated in  FIG. 1 . 
     As illustrated in  FIGS. 8 and 9 , the device information stored in the storage unit  340  includes the IP address, the MAC address, the serial number, a connection flag, and the status information. In  FIGS. 8 and 9 , the device information in the first line (serial number “A12345” or the like) represents information of the PC 10 , the device-information in the second line (serial number of “B12345” or the like) represents information of the PC 11 , the device information in the third line (serial number of “C12345” or the like) represents information of the device  20 , and the device information in the fourth line (serial number of “D12345” or the like) represents information of the device  21 . Further, the connection flag is information representing a connection of the device. A number “0” represents network connection, and a number “1” represents local connection. 
     In  FIG. 1 , the device  20  is locally connected with the PC 10 . Therefore, the controller  350  receives, as the device information of the device  20 , for example, the response to acquisition of the device information, including the IP address “192.168.10.10”, MAC address “AA:AA:AA:00:00:01”, serial number “C12345”, and status information such as counter information “120” or error information “-” of the PC 10 . Therefore, as illustrated in  FIG. 8 , the controller  350  registers values of the received device information of the device  20  to the storage unit  340 , and sets a value of the connection flag to “1”. 
     After that, when the connection illustrated in  FIG. 1  is switched to the connection illustrated in  FIG. 2 , the device  20  locally connected to the PC 11  causes the controller  350  to receive the response to acquisition of the device information, as the device information of the device  20 , including for example, the IP address “192.168.10.11”, MAC address “BB:BB:BB:00:00:01”, serial number “C12345”, and status information such as counter information “190” or error information “-” of the PC 11 . Therefore, as illustrated in  FIG. 9 , the controller  350  updates the IP address and the MAC address to a value of the PC 11 , and additionally registers the status information of the device  20  to the storage unit  340 . 
       FIG. 10  is a flowchart illustrating exemplary processing performed when the PC  10  detects the connection of the device  20  in the device management system  1  according to the present embodiment. 
     The detection part  171  detects the connection with the local device through the communication interface  3  (step S 101 ). 
     Then the transmission part  161  transmits the TRAP of the SNMP to the device management apparatus  30  (step S 103 ). The TRAP from the SNMP includes the IP address of the PC 10 . 
     The reception part  162  receives polling (device information acquisition request) from the device management apparatus  30  based on the TRAP from the SNMP (step S 105 ). 
     Next, the protocol conversion module is determined by the protocol determination module  172  of the first protocol conversion module  180  to n-th protocol conversion module  190 . The protocol conversion module determined by the protocol determination module  172  converts the device information acquisition request to the device information acquisition request for the protocol of itself, communicates with the local device, and acquires the device information of the local device. The protocol conversion module converts the acquired device information of the local device to device information for the protocol for response to acquisition of the device information, acquires the IP address and MAC address of the PC  10  from the device information storage unit  141 , and generates the response to acquisition of the device information including the IP address and MAC address of the PC  10 , and the converted device information of the local device (step S 107 ). 
     The transmission part  161  then transmits the response to acquisition of the device information which has been generated by the protocol conversion module to the device management apparatus  30  (step S 109 ). 
       FIG. 11  is a flowchart illustrating exemplary processing performed when the PC  10  detects the disconnection of the device  20  in the device management system  1  according to the present embodiment. 
     First, the detection part  171  detects the disconnection of the local device through the communication interface  3  (step S 201 ). 
     Then the transmission part  161  transmits the TRAP of the SNMP to the device management apparatus  30  (step S 203 ). The TRAP from the SNMP includes the IP address of the PC 10 . 
     Next, the reception part  162  receives the polling (device information acquisition request) from the device management apparatus  30  based on the TRAP from the SNMP (step S 205 ). 
     Next, the generation part  163  acquires the IP address and MAC address of the PC  10 , and the device information of the local device from the device information storage unit  141  to generate the response to acquisition of the device information, and the transmission part  161  transmits the response to acquisition of the device information to the device management apparatus  30  (step S 207 ). 
       FIG. 12  is a flowchart illustrating exemplary protocol determination of the device management apparatus  30  according to the present embodiment. 
     First, when receiving the TRAP from the SNMP, the controller  350  of the device management apparatus  30  performs test communication using a protocol not tested yet (step S 301 ) to confirm whether a response has been received (step S 303 ). 
     When the response has not been received (step S 303 , No), the processing is returned to step S 301 . 
     On the other hand, when the response has been received (step S 303 , Yes), the protocol used for the test communication in which the response has been received is determined (step S 305 ), and the protocol is used to transmit the polling (device information acquisition request) (step S 307 ). 
       FIG. 13  is a flowchart illustrating exemplary determination of the protocol conversion module for the PCs  10  and  11  according to the present embodiment. 
     First, when the device information acquisition request is received by the reception part  162 , the protocol determination module  172  makes test communication for a port not tested using a protocol conversion module not tested (step S 401 ) to confirm whether a response has been received (step S 403 ). 
     When the response has not been received (step S 403 , No), the processing is returned to step S 401 . 
     On the other hand, when the response has been received (step S 403 , Yes), the protocol conversion module used for the test communication in which the response has been received is determined (step S 405 ), and the protocol conversion module is used to perform model determination communication (step S 407 ). 
     When the response has not been received (step S 409 , No), the processing is returned to step S 407 . 
     On the other hand, when the response has been received (step S 409 , Yes), the model of the local device is determined as a model according to the model determination communication in which the response has been received (step S 411 ). 
     As described above, according to the present embodiment, when the connection of the local device is detected, the device management apparatus  30  is notified of the TRAP and makes a device information acquisition request based on the notification. Therefore, even if the PC connected to the local device is switched to another one, the another PC newly connected to the local device is readily grasped by the device management apparatus  30 . 
     Further, according to the present embodiment, when the disconnection of the local device is detected, the device management apparatus  30  is notified of the TRAP and makes a device information acquisition request based on the notification. Therefore, even if the PC connected to the local device is switched to another one, information of the local device managed by the PC is readily grasped by the device management apparatus  30 . 
     MODIFICATION 
     It is noted that the present invention is not limited to the above-mentioned embodiment, and various modifications are possible. 
     First Modification 
     For example, in the above-mentioned embodiment, when the PC to which the local device is connected is switched to another one, the device management apparatus  30  updates the IP address and MAC address of the PC to continue the management of the local device. However, as illustrated in  FIG. 14 , device information of a local device may be managed for each PC having been connected. 
     Second Modification 
     For example, in the above-mentioned embodiment, the local device such as the device  20  is the projector. However, the local device may be for example a printer. 
       FIG. 18  is a block diagram illustrating an exemplary configuration of a device  420  according to a modification. As illustrated in  FIG. 18 , the device  420  includes a communication unit  210 , an operating unit  220 , a display unit  230 , a storage unit  240 , a controller  250 , and a printing unit  460 . 
     The communication unit  210 , the operating unit  220 , the display unit  230 , the storage unit  240 , and the controller  250  are configured similarly to those of the above-mentioned embodiment. 
     When printing is requested from the PC  10  or  11  using PJL, the printing unit  460  performs printing. 
     In such a configuration, the protocol conversion module formats the acquired device information of the local device in XML data as illustrated in  FIG. 15 , parses data of a “Variable” tab of the formatted XML data, and converts the parsed data for a protocol (XML) for response to acquisition of the device information. It is noted that the protocol conversion module may format the acquired device information of the local device in MIB data as illustrated in  FIG. 16 , and may convert the formatted MIB data for the protocol (SNMP) for response to acquisition of the device information. 
     (Hardware Configuration) 
       FIG. 17  is a block diagram illustrating an exemplary hardware configuration of PCs  10  and  11  and a device management apparatus  30  according to the present embodiment. As illustrated in  FIG. 17 , according to the present embodiment, the PCs  10  and  11  and the device management apparatus  30  include a control device  901  such as a CPU, a storage device  902  such as a ROM or RAM, an external storage device  903  such as an HDD or SSD, a driving device  904 , an input device  905  such as a mouse or keyboard, a display device  906  such as a display, a communication device  907  such as an NIC, and an interface device  908 . The devices are connected to one another by a bus B. The PCs and the device management apparatus can be configured with hardware using a normal computer. 
     The agent program executed on the PCs  10  and  11  according to the present embodiment and the device management program executed on the device management apparatus  30  according to the present embodiment are provided. The programs have an installable or executable file to be stored in a computer-readable storage medium such as a CD-ROM, a CD-R, a memory card, a digital versatile disk (DVD), or a flexible disk (FD). 
     The agent program executed on the PCs  10  and  11  according to the present embodiment and the device management program executed on the device management apparatus  30  according to the present embodiment may be provided by being stored on a computer connected to a network, such as the Internet, to be downloaded through the network. The agent program executed on the PCs  10  and  11  according to the present embodiment and the device management program executed on the device management apparatus  30  according to the present embodiment may be provided or distributed through the network such as the Internet. The agent program executed on the PCs  10  and  11  according to the present embodiment and the device management program executed on the device management apparatus  30  according to the present embodiment may be provided by being incorporated into the ROM or the like in advance. 
     The agent program executed on the PCs  10  and  11  according to the present embodiment and the device management program executed on the device management apparatus  30  according to the present embodiment have a module structure for implementation of each unit mentioned above on the computer. As actual hardware, the control device  901  executes a program having been read on the storage device  902  from the external storage device  903 , whereby each unit is implemented on the computer. 
     According to the present invention, even if an information processing apparatus connected to a device is switched to another one, a device management apparatus is allowed to grasp the another information processing apparatus newly connected to the device in a simple manner. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.