Abstract:
An information collecting apparatus which is capable of reliably collecting information without troubling a user or a service person even when there is no device capable of playing the role of a server to collect information on its behalf. The apparatus collects information on network devices connected to a network. The collected information is transmitted to a server. When the apparatus cannot continue information collection, it is determined whether or not any network device is provided with the information collecting function. If any of them is provided, the apparatus instructs the device to execute the function, whereas if none of them is provided with the function, the apparatus instructs the device to transmit information on the device itself to the server.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an information collecting apparatus for collecting maintenance information and the like (counter information, error log information, consumable component information, etc.) on network apparatuses connected to a network, a method of controlling the information collecting apparatus, a network apparatus, a method of controlling the network apparatus, and a storage medium storing each of programs for implementing the methods. 
     2. Description of the Related Art 
     Devices, typified by an image forming apparatus, each store a large amount of maintenance information including management data and log data for management thereof, and consumable component information. Further, in recent years, devices of the above-mentioned type have been networked, i.e. mostly connected to networks so as to be operated as network apparatuses. 
     In this situation, there has been proposed a system in which a user collects management information from devices (network apparatuses) on a LAN to perform centralized management of the devices. Further, a system in which pieces of information on devices are collected in a server apparatus on the Internet for centralized management has also been proposed so as to facilitate device maintenance by a service person. 
     Further, there have been proposed two methods of achieving the system in which pieces of information are collected in a server apparatus on the Internet. In a first method, an information collecting device collects information on a plurality of devices on the same network and collectively sends the device information to the server apparatus on the Internet, while in a second method, each device sends information on itself to the server apparatus. 
     There has also been proposed a technique in which in the former method, a second-priority device is provided in advance to be reserved for occurrence of a trouble with the information collecting device, and when a trouble occurs in the information collecting device, the second-priority device substitutes for the information collecting device (see e.g. Japanese Patent Laid-Open Publication No. 2006-040258). 
     However, a problem with the above-mentioned prior art is that a device for operating on behalf of the information collecting device as the second-priory device does not always exist, and hence when no such second-priority device which can operate on behalf of the information collecting device exists, the collection of device information cannot be continued. Further, in the prior art, even if the second-proxy device exists, it does not take over data collected so far, which can cause some omission in collected information. 
     SUMMARY OF THE INVENTION 
     The present invention provides an information collecting apparatus which is capable of reliably collecting information without troubling a user or a service person even when there is no device capable of playing the role of a server to collect information on its behalf, to thereby improve user friendliness, a method of controlling the information collecting apparatus, a network apparatus and a method of controlling the same, and a storage medium storing programs for implementing the methods. 
     In a first aspect of the-present invention, there is provided an information collecting apparatus comprising a collecting unit configured to collect apparatus information on a network apparatus connected to a network, a transmission unit configured to transmit the apparatus information collected by the collecting unit to an information processing apparatus on the network, a determination unit configured to be operable when the information collecting apparatus cannot continue collection of apparatus information by the collecting unit, to determine whether or not the network apparatus is provided with a function for collecting apparatus information, and a transfer unit configured to be operable when it is determined by the determination unit that the network apparatus is provided with the function, to instruct the network apparatus to execute the function, and when it is determined that the network apparatus is not provided with the function, to instruct the network apparatus to transmit apparatus information on the network apparatus itself to the information processing apparatus. 
     In a second aspect of the present invention, there is provided a network apparatus connected to a network, comprising a reception unit configured to receive a transmission request for transmitting apparatus information on the network apparatus, from an information collecting apparatus connected to the network, a transmission unit configured to transmit the apparatus information on the network apparatus to the information collecting apparatus in response to the transmission request received by the reception unit, a second reception unit configured to receive, from the information collecting apparatus connected to the network, an instruction for transmitting the apparatus information on the network apparatus to an information processing apparatus connected to the network, and a second transmission unit configured to transmit the apparatus information on the network apparatus to the information processing apparatus in response to the instruction received by the second reception unit. 
     In a third aspect of the present invention, there is provided a method of controlling an information collecting apparatus, comprising collecting apparatus information on a network apparatus connected to a network, transmitting the apparatus information collected by the collecting to an information processing apparatus on the network, determining, when the information collecting apparatus cannot continue collection of apparatus information by the collecting, whether or not the network apparatus is provided with a function for collecting apparatus information, and instructing the network apparatus to execute the function when it is determined by the determining that the network apparatus is provided with the function, and to transmit apparatus information on the network apparatus itself to the information processing apparatus when it is determined by the determining that the network apparatus is not provided with the function. 
     In a fourth aspect of the present invention, there is provided a method of controlling a network apparatus connected to a network, comprising receiving a transmission request for transmitting apparatus information on the network apparatus, from an information collecting apparatus connected to the network, transmitting the apparatus information on the network apparatus to the information collecting apparatus in response to the transmission request received by the receiving, receiving, from the information collecting apparatus connected to the network, an instruction for transmitting the apparatus information on the network apparatus to an information processing apparatus connected to the network, and transmitting the apparatus information on the network apparatus to the information processing apparatus in response to the received instruction. 
     In a fifth aspect of the present invention, there is provided a computer-readable storage medium storing a program for causing a computer to execute a method of controlling an information collecting apparatus, wherein the method comprises collecting apparatus information on a network apparatus connected to a network, transmitting the apparatus information collected by the collecting to an information processing apparatus on the network, determining, when the information collecting apparatus cannot continue collection of apparatus information by the collecting, whether or not the network apparatus is provided with a function for collecting apparatus information, and instructing the network apparatus to execute the function when it is determined by the determining that the network apparatus is provided with the function, and to transmit apparatus information on the network apparatus itself to the information processing apparatus when it is determined by the determining that the network apparatus is not provided with the function. 
     In a sixth aspect of the present invention, there is provided a computer-readable storage medium storing a program for causing a computer to execute a method of controlling a network apparatus connected to a network, wherein the method comprises receiving a transmission request for transmitting apparatus information on the network apparatus, from an information collecting apparatus connected to the network, transmitting the apparatus information on the network apparatus to the information collecting apparatus in response to the transmission request received by the receiving, receiving, from the information collecting apparatus connected to the network, an instruction for transmitting the apparatus information on the network apparatus to an information processing apparatus connected to the network, and transmitting the apparatus information on the network apparatus to the information processing apparatus in response to the received instruction. 
     According to the information collecting apparatus of the present invention, it is possible to reliably collect information without troubling a user or a service person even when there is no device capable of playing the role of a server to collect information on its behalf, to thereby improve user friendliness 
     The features and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of an image forming apparatus-monitoring system as an information collecting system including an information collecting apparatus according to an embodiment of the present invention. 
         FIG. 2  is a block diagram showing a hardware configuration common to a plurality of image forming apparatuses appearing in  FIG. 1 . 
         FIG. 3  is a block diagram showing a software configuration of each of image forming apparatuses, appearing in  FIG. 1 , provided with both an information collecting function and an information transmitting function. 
         FIG. 4  is a block diagram showing a software configuration for realizing the information transmitting function of each of image forming apparatuses which do not have the information collecting function. 
         FIG. 5  is a flowchart of an information collecting function-enabling process executed by the  FIG. 3  image forming apparatus having both the information collecting function and the information transmitting function, at the start of the apparatus. 
         FIG. 6  is a flowchart of an information transmitting function-enabling process executed by the  FIG. 4  image forming apparatus which does not have the information collecting function, at the start of the apparatus. 
         FIG. 7  is a flowchart of an information collecting process executed by the  FIG. 3  image forming apparatus. 
         FIG. 8  is a diagram showing an example of information compiled in a step in  FIG. 7 . 
         FIG. 9  is a flowchart of a power switch-off process executed when a power switch of the  FIG. 2  image forming apparatus is turned off. 
         FIG. 10  is a diagram useful in explaining an example of a priority calculating method employed in a step in  FIG. 9 . 
         FIG. 11  is a flowchart of a request receiving process executed when the  FIG. 3  image forming apparatus has received a request. 
         FIG. 12  is a flowchart of a request receiving process executed when the  FIG. 4  image forming apparatus has received a request. 
         FIG. 13  is a flowchart of an information transmitting process for transmitting information to a server apparatus, which is executed in a case where the information collecting function or the information transmitting function of the  FIG. 2  image forming apparatus is enabled. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present invention will now be described in detail below with reference to the accompanying drawings showing an embodiment thereof. 
       FIG. 1  is a diagram of an image forming apparatus-monitoring system as an information collecting system including an information collecting apparatus according to the embodiment of the present invention. 
     As shown in  FIG. 1 , the image forming apparatus-monitoring system is constructed by connecting image forming apparatuses  101  to  105  to a LAN  106  and interconnecting a server apparatus  108  and the image forming apparatuses  101  to  105  via the Internet  107 . In short, the image forming apparatuses  101  to  105  are examples of a network apparatus the present invention which is connected to a network in. Further, the server apparatus  108  is an example of an information processing apparatus in the present invention. 
     The image forming apparatus  101  monitors the status of each of the image forming apparatuses  102  to  105  and the image forming apparatus  101  itself, and collects maintenance information including counter information, error log information, and consumable component information. The image forming apparatus  101  sends the collected information to the server apparatus  108  in predetermined timing. 
     The server apparatus  108  receives maintenance information from the image forming apparatus  101  and other client apparatuses (not shown), and manages the information in a centralized manner. 
     It is assumed that each of the image forming apparatuses  102  and  103  is provided with the same functions as those of the image forming apparatus  101 . More specifically, each of the image forming apparatuses  102  and  103  is provided with a software module for collecting information from other image forming apparatuses. Further, it is assumed that each of the image forming apparatuses  104  and  105  is not provided with a software module for collecting information from other image forming apparatuses, but is capable of sending information on itself directly to the server apparatus  108 . 
     In short, each of the image forming apparatuses  101  to  103  can function as an information collecting apparatus for collecting apparatus information on network apparatuses interconnected via the network. 
       FIG. 2  is a block diagram showing a hardware configuration common to the image forming apparatuses  101  to  105  appearing in  FIG. 1 . 
     A scanner interface controller  201  of each of the image forming apparatuses  101  to  105  controls a scanner  212 . A CPU  202  executes software programs for the image forming apparatus to thereby control the overall operation of the apparatus. 
     A ROM (Read Only Memory)  203  stores a boot program, fixed parameters, etc. for the apparatus. A RAM (Random Access Memory)  204  is used by the CPU  202  so as to temporarily store data and load software programs for control of the apparatus. 
     A storage device  205  is implemented e.g. by a hard disk drive or a flash memory. The storage device  205  is used to store various kinds of data. Data to be collected is also stored in the storage device  205 . A printer interface controller  206  controls a printer  211 . 
     A NVRAM (Nonvolatile RAM)  207  stores various settings for the printer. A panel controller  208  controls an operation panel  213  for displaying various kinds of information and receiving input of instructions from the user. 
     A network interface controller  209  controls transmission and reception of data to and from the network (LAN  106 ). Connected to a bus (system bus)  210  are the scanner interface controller  201 , the CPU  202 , the ROM  203 , the RAM  204 , the storage device  205 , the printer interface controller  206 , the NVRAM  207 , the panel controller  208 , and the network interface controller  209 . Control signals from the CPU  202  and data signals from the various devices are transmitted or received via the bus  210 . 
     Although in  FIG. 2 , the copying machine provided with the scanner and the printer is illustrated as an example of the image forming apparatus, the image forming apparatus may be implemented by a device other than the copying machine. That is, it may be implemented by a printer, a scanner, a facsimile machine, or a multi-function peripheral, for example. 
       FIG. 3  is a block diagram showing a software configuration of each of the image forming apparatuses  101  to  103  appearing in  FIG. 1 , which has both an information collecting function and an information transmitting function. 
     Each of the image forming apparatuses  101  to  103  has an information collecting functional block and an information transmitting functional block described hereafter. More specifically, the functional blocks are comprised of a device search section  301 , a device information acquisition section  302 , a function management section  303 , a schedule management section  304 , a collected information storage section  305 , an information collection management section  306 , a function transfer section  307 , an information transmitting section  308 , and a request receiving section  309 . 
     The device search section  301  searches for devices to be managed (network apparatuses; image forming apparatuses) which are connected to the network. 
     The device information acquisition section  302  acquires device information (a list of available functions, a list of enabled functions, various kinds of maintenance information including error log information and consumable component information, etc.) from each of the other devices (apparatuses). The device information acquisition section  302  is an example of a collecting unit in the present invention, which is configured to collect apparatus information on network apparatuses connected to the network, which are found by the device search section  301 . 
     The function management section  303  enables or disables available functions of the apparatus to which it belongs. A schedule management section  304  manages a timing schedule for acquiring information from each of the other devices (apparatuses) and a timing schedule for transmitting information to the server apparatus  108 . 
     The collected information storage section  305  cumulatively stores information collected from the other devices (apparatuses). The information collection management section  306  manages devices (apparatuses) from which to collect information, compiles collected information on a device-by-device basis to thereby calculate the availability and the like of each of the devices, and determines the priorities of the respective devices in suitability for causing the information collecting function to operate. 
     The function transfer section  307  transfers the information collecting function to another device (apparatus) at the shutdown of the image forming apparatus. The function transfer section  307  is an example of a transfer unit in the present invention, which is configured to be operable when the network apparatus to which the function transfer unit belongs is to be shut down, to request another network apparatus to take over the information collecting function of a collecting unit, or to send apparatus information on its own. 
     Specifically, the function transfer section  307  requests another network apparatus (the image forming apparatus  102  or  103  in the case of the image forming apparatus  101  having the function transfer section  307 ) equipped with the information collecting function but not having the same enabled to take over the information collecting function of the network apparatus (the image forming apparatus  101  in the above-mentioned example) by enabling the information collecting function of its own. 
     Further, the function transfer section  307  requests another network apparatus (the image forming apparatus  104  or  105 ) which does not have the information collecting function, but is capable of sending apparatus information on the network apparatus itself, to send apparatus information on themselves. 
     The information collection management section  306  serves as a priority determination unit configured to determine the priorities of the respective network apparatuses before the function transfer section  307  requests another network apparatus having the information collecting function to take over the information collecting function. 
     The priority determination unit calculates a priority index using at least one of the frequency of process execution by each of the other network apparatuses and the response rate to requests for information collection, as a parameter. 
     The information transmitting section  308  sends information cumulatively stored in the collected information storage section  305  to the server apparatus  108 , or sends information on the device (apparatus) to which the information transmitting section  308  belongs in response to a request from another device. The request receiving section  309  receives an information transmission request or the information collecting function takeover request from another device and performs processing associated therewith. 
       FIG. 4  is a block diagram showing a software configuration for realizing the information transmitting function of each of the image forming apparatuses  104  and  105  appearing in  FIG. 1 . 
     The information transmitting function of the image forming apparatus  104  ( 105 ) is comprised of a device search section  401 , a function management section  402 , a schedule management section  403 , an information transmitting section  404 , and a request receiving section  405 . 
     The device search section  401  searches for devices to be managed which are connected to the network. The function management section  402  enables or disables available functions of the image forming apparatus  104  to which it belongs. The schedule management section  403  manages a timing schedule for transmitting information to the server apparatus  108 . 
     The information transmitting section  404  sends maintenance information on the image forming apparatus  104  ( 105 ) to which it belongs to the server apparatus  108  in timing scheduled by the schedule management section  403  (serving as a second transmission unit of a network apparatus connected to a network, in the present invention). Further, the information transmitting section  404  sends device information on the image forming apparatus  104  ( 105 ) to another device (apparatus) in response to a request from the same (serving as a transmission unit of the network apparatus in the present invention). The request receiving section  405  performs processing in response to an information transmission request, an information transmitting function-enabling request, or an information transmitting function-disabling request received from another device (apparatus) (serving as a second transmission unit of the network apparatus in the present invention). 
     The request receiving section  405  receives from an information collecting apparatus (one of the image forming apparatuses  101  to  103 ) a request for transmitting apparatus information on the image forming apparatus  104  ( 105 ) (serving as a transmission unit of the network apparatus in the present invention). 
     Next, processes executed at the start of an image forming apparatus will be described with reference to  FIGS. 5 and 6 . 
       FIG. 5  is a flowchart of an information collecting function-enabling process executed by each of the image forming apparatuses  101  to  103  at the start of the apparatus. The following description will be given using the image forming apparatus  101  as a representative of the image forming apparatuses  101  to  103 . 
     When the power of the image forming apparatus  101  is turned on, first in a step S 501 , the image forming apparatus  101  searches for devices to be managed (image forming apparatuses) based on a device list. Information of the device list is input by a service person when each device (apparatus) is installed, or is received from the server apparatus  108  and stored in the device (apparatus), and it is assumed that all the devices (apparatuses) to be managed store the device list. 
     Then, it is determined in a step S 502  whether or not there is a device having its information collecting function enabled. If it is determined that there is a device having its information collecting function enabled, the present process is terminated. 
     If it is determined in the step S 502  that there is no device having its information collecting function enabled, the process proceeds to a step S 503 , wherein the image forming apparatus  101  enables its own information collecting function. 
     Then, the process proceeds to a step S 504 , wherein it is determined whether or not there is a device having its information transmitting function enabled on the network. If it is determined that there is no device having its information transmitting function enabled, the present process is terminated. 
     If it is determined in the step S 504  that there is at least one device having its information transmitting function enabled, the process proceeds to a step S 505 , wherein the image forming apparatus  101  sends an information transmitting function-disabling request to each device having its information transmitting function enabled, followed by terminating the present process. 
       FIG. 6  is a flowchart of an information transmitting function-enabling process executed by each of the  FIG. 4  image forming apparatuses  104  and  105  at the start of the apparatus. The following description will be given using the image forming apparatus  104  as a representative of the image forming apparatuses  104  and  105 . 
     When the power of the image forming apparatus  104  is turned on, first in a step S 601 , the image forming apparatus  104  searches for devices (apparatuses) to be managed, based on the device list. 
     Then, it is determined in a step S 602  whether or not there is a device having its information collecting function enabled. If it is determined that there is a device having its information collecting function enabled, the present process is terminated. 
     If it is determined in the step S 602  that there is no device which has its information collecting function enabled, the process proceeds to a step S 603 . In the step S 603 , the image forming apparatus  104  enables its own information transmitting function, followed by terminating the present process. 
     The above-described processes make it possible to use the information collecting function for centralized management when at least one device has the information collecting function, and enable each of the devices (apparatuses) to transmit information by itself to the server apparatus  108  when there is no device having the information collecting function enabled. 
     Next, an information collecting process executed in a case where the information collecting function is enabled in one of the image forming apparatuses  101  to  103  will be described with reference to  FIGS. 7 and 8 . 
       FIG. 7  is a flowchart of an information collecting process executed by one of the image forming apparatuses  101  to  103 . As in the case of the  FIG. 5  flowchart, the following description will be given using the image forming apparatus  101  as a representative of the image forming apparatuses  101  to  103 . 
     The present process is executed in timing scheduled by the schedule management section  304 . 
     When it is a scheduled time to collect information, first in a step S 701 , the image forming apparatus  101  attempts to acquire status information from devices (apparatuses) connected to the network. Then, it is determined in a step S 702  whether or not the information acquisition is successful. If the information acquisition is successful, the process proceeds to a step S 703 . 
     In the step S 703 , the acquired status information is compared with status information already cumulatively stored, whereby it is determined whether or not any of the devices (apparatuses) is in a status changed from the corresponding status on which information was acquired on the immediately preceding occasion. If it is determined in the step S 703  that any of the devices (apparatuses) is in a changed status, the process proceeds to a step S 704 . 
     In the step S 704 , various kinds of counter values (e.g. a component count, a copy count, etc.), log information (e.g. a jam log, a warning log, and an error log), and specification information are acquired from the device (apparatus). Then, the process proceeds to a step S 705 , wherein count change information is updated. Then, the process proceeds to a step S 706 , and polling response rate information is updated, followed by terminating the present process. 
     On the other hand, if it is determined in the step S 702  that the information acquisition is unsuccessful, or if it is determined in the step S 703  that there is no device (apparatus) in a changed status, the process directly proceeds to the step S 706 , wherein the polling response rate information is updated, followed by terminating the present process. 
       FIG. 8  is a diagram showing the information compiled in the steps S 705  and S 706  in  FIG. 7 . 
     A spec (specification)  801  is information indicative of whether or not the device is provided with the information collecting function. A device having the information collecting function is indicated by a value of 1 set to the spec  801 , whereas a device having no information collecting function is indicated by a value of 0 set to the same. 
     A count change rate  802  is information indicative of the frequency of job execution by an associated device. This rate is calculated e.g. by the equation of “new count change rate=old count change rate×0.9+(last per-minute increment of count+1)×0.1”. As this value is larger, it indicates that an  10  associated device is more often used by users, and therefore it is desirable to operate the information collecting function using a device having a lower value of the count change rate. 
     A polling response rate  803  is  15  information indicative of the availability of an associated device. This rate is calculated e.g. by the equation of “new polling response rate=old polling response rate×0.95+response×0.05” (response=1 when it is determined in the step S 702  that the  20  information acquisition is successful, and response=0 when it is determined in the step S 702  that the information acquisition is unsuccessful). A device having a lower value of the polling response rate is less likely to have its power supply turned off, and  25 . therefore it is preferable to operate the information collecting function using a device having a lower value of the polling response rate. 
     Next, a process executed before turn-off of the power of each of the image forming apparatuses  101  to  103  will be described with reference to  FIGS. 9 and 10 . The following description will be given using the image forming apparatus  101  as a representative of the image forming apparatuses  101  to  103 . 
       FIG. 9  is a flowchart of a power switch-off process executed when a power switch, not shown, of the image forming apparatus  101  is turned off. 
     When the power switch is turned off, a shutdown request is detected in a step S 901 . Then, the process proceeds to a step S 902 , wherein the image forming apparatus  101  determines whether or not its own information collecting function is in an enabled state. 
     If it is determined in the step S 902  that the information collecting function is not in an enabled state, the process proceeds to a step S 910 , wherein shutdown processing is executed, followed by terminating the present process. If it is determined in the step S 902  that the information collecting function is in an enabled state, the process proceeds to a step S 903 . 
     In the step S 903 , priorities of devices which are to be requested to take over the information collecting function are determined based on the compiled information shown in  FIG. 8 . 
       FIG. 10  is a diagram useful in explaining an example of a priority calculating method employed in the step  903  in  FIG. 9 . 
     In the present example, each priority is calculated by weighting the count change rate and the polling response rate of each device. When the method is applied to the case shown in  FIG. 8 , a top priority is given to the device (image forming apparatus)  103 , and a second priority is given to the device (image forming apparatus)  102 . 
     When the priorities are determined in the step S 903 , the process proceeds to the following step S 904 . In the step S 904 , a device given the top priority is selected, and the process proceeds to a step S 905 . 
     In the step S 905 , the information collecting function takeover request is sent to the device selected in the step S 904 , together with configuration information required for information collection, information collected so far, and schedule information. 
     Then, the process proceeds to a step S 906 , wherein it is determined whether or not the takeover request has been accepted. If the takeover request has been accepted, the process proceeds to the step S 910 , and the shutdown processing is executed, followed by terminating the present process. If it is determined in the step S 906  that the transfer of the information collecting function so as to cause the information collecting function to be taken over is unsuccessful, the process proceeds to a step S 907 . 
     In the step S 907 , it is determined whether or not the transfer of the information collecting function has been unsuccessfully carried out for all of the devices provided with the information collecting function (though not enabled). If the transfer of the information collecting function has not been unsuccessfully carried out for all of the devices provided with the information collecting function, the process returns to the step S 904 , wherein a device given a second priority is selected as a device to take over the information collecting function, i.e. a device to which the information collecting function is to be transferred. 
     If it is determined in the step S 907  that the transfer of the information collecting function has been unsuccessfully carried out for all of the devices provided with the information collecting function, the process proceeds to a step S 908 . In the step S 908 , an information transmitting function-enabling request is sent to devices in which the information collecting function is not in operation. 
     For example, when the device (image forming apparatus)  101  attempts to transfer the information collecting function to the devices  103  and  102  in the situation shown in  FIG. 10  and the attempt fails, the information transmitting function-enabling request is sent to the devices  104  and  105 . 
     Then, the process proceeds to a step S 909 , wherein data collected so far is sent to the server  108 . Thereafter, shutdown processing is executed in the step S 910 , followed by terminating the present process. 
     Next, request receiving processes executed when image forming apparatuses of the above-described two types receive respective requests will be described with reference to  FIGS. 11 and 12 . 
       FIG. 11  is a flowchart of a request receiving process executed by each of the image forming apparatuses  101  to  103  when the image forming apparatus has received a request. 
     First, when a request is received in a step S 1101 , the process proceeds to a step S 1102 , wherein it is determined whether or not the received request is an information transmission request. If the received request is an information transmission request, the process proceeds to a step S 1103 . In the step S 1103 , requested information is transmitted (sent as a response) to a requesting device (apparatus), followed by terminating the present process. 
     On the other hand, if it is determined in the step S 1102  that the received request is not an information transmission request, the process proceeds to a step S 1104 . In the step S 1104 , it is determined whether or not the received request is an information collecting function takeover request. If the received request is not an information collecting function takeover request, the present process is terminated. 
     On the other hand, if it is determined that the received request is an information collecting function takeover request, the process proceeds to a step S 1105 , wherein configuration information (a proxy setting, a server address, schedule information, etc.) required for an operation of the information collecting function, and information collected so far are received from the requesting device (apparatus). 
     Then, the process proceeds to a step S 1106 , wherein settings of the device are changed based on the configuration information received in the step S 1105 . Then, the process proceeds to a step S 1107 , wherein the information collecting function of its own is enabled, followed by terminating the present process. 
       FIG. 12  is a flowchart of a request receiving process executed by each of the image forming apparatuses  104  and  105 , shown in  FIG. 4 , when the image forming apparatus receives a request. 
     First, when a request is received in a step S 1201 , the process proceeds to a step S 1202 , wherein it is determined whether or not the received request is an information transmission request. If the received request is an information transmission request, the process proceeds to a step S 1203 . In the step S 1203 , requested information is transmitted (sent as a response) to a requesting device (apparatus), followed by terminating the present process. 
     On the other hand, if it is determined in the step S 1202  that the received request is not an information transmission request, the process proceeds to a step S 1204 . In the step S 1204 , it is determined whether or not the received request is an information transmitting function start request. If the received request is an information transmitting function start request, the process proceeds to a step S 1205 , wherein the information transmitting function of its own is enabled, followed by terminating the present process. 
     If it is determined in the step S 1204  that the received request is not an information transmitting function start request, the process proceeds to a step S 1206 , wherein it is determined whether or not the received request is an information transmitting function stop request. 
     If the received request is not an information transmitting function stop request, the present process is immediately terminated, whereas if the received request is an information transmitting function stop request, the process proceeds to a step S 1207 , wherein the information transmitting function of its own is disabled (stopped), followed by terminating the present process. 
     Next, an information transmitting process executed by an image forming apparatus for transmission of information will be described with reference to  FIG. 13 . 
       FIG. 13  is a flowchart of the information transmitting process for transmitting information to the server apparatus, which is executed by each of the image forming apparatuses in a case where the information collecting function or the information transmitting function of the image forming apparatus is enabled. 
     First, it is determined in a step S 1301  whether or not it is time scheduled by the schedule management section  304  or  403 . If it is not the scheduled time yet, the process returns to the step S 1301 , whereas if it is the scheduled time, the process proceeds to a step S 1302 . 
     In the step S 1302 , information is sent to the server apparatus  108 . A device having its information collecting function enabled sends collected information to the server apparatus  108 , while a device having its information transmitting function enabled sends information on the device itself at the present time to the server apparatus  108 . Then, the process proceeds to a step S 1303 , wherein a next transmission time is scheduled, followed by terminating the present process. 
     As described above, following an instruction from a device of which the information collecting function is enabled for operation, another device has its information collecting function enabled to take over the information collecting function, or when there is no device which is to take over the information collecting function, other devices which are not provided with the information collecting function have their information transmitting function enabled, whereby it is possible to reliably send maintenance information to the server apparatus  108 . 
     Although in the present embodiment, information is collected from image forming apparatuses, this is not limitative, but the present invention can also be applied to any kinds of network devices (apparatuses), such as personal computers and server apparatuses. 
     Further, although in the present embodiment, the image forming apparatus  104  ( 105 ) actively searches for a device of which the information collecting function is enabled, at the start of the apparatus, this is not limitative, but the image forming apparatus  104  ( 105 ) may detect that no regular information transmission request is received from an information collecting device, to thereby determine that there is no device having the information collecting function enabled. 
     Further, although in the present embodiment, each of the devices to be managed stores the device list and performs a device search at the start of the apparatus, based on the device list, SNMP broadcast may be used to search for a device of which the information collecting function is enabled. 
     Furthermore, although in the present embodiment, priorities are determined based on three kinds of information, i.e. the specification information, the count change rate information, and the polling response rate information, this is not limitative, but other indicators, such as latest CPU occupancy, may be used. 
     What is more, although the specification information (spec  801 ) is provided as information of a two-valued variable indicating whether or not the information collecting function is operable, i.e. whether or not the information collecting function is at least provided irrespective of whether it is enabled, more detailed ranks may be set e.g. according to CPU performance and hard disk capacity, and weighted for determination of the aforementioned priorities. 
     It is to be understood that the present invention may also be accomplished by supplying a system or an apparatus with a storage medium in which a program code of software, which realizes the functions of the above described embodiment, is stored, and causing a computer (or CPU or MPU) of the system or apparatus to read out and execute the program code stored in the storage medium. 
     In this case, the program code itself read from the storage medium realizes the functions of the above described embodiment, and therefore the program code and the storage medium in which the program code is stored constitute the present invention. 
     Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magnetic-optical disk, an optical disk, such as a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, a DVD-RW, or a DVD+RW, a magnetic tape, a nonvolatile memory card, and a ROM. Alternatively, the program may be downloaded via a network. 
     Further, it is to be understood that the functions of the above described embodiment may be accomplished not only by executing the program code read out by a computer, but also by causing an OS (operating system) or the like which operates on the computer to perform a part or all of the actual operations based on instructions of the program code. 
     Further, it is to be understood that the functions of the above described embodiment may be accomplished by writing a program code read out from the storage medium into a memory provided on an expansion board inserted into a computer or a memory provided in an expansion unit connected to the computer and then causing a CPU or the like provided in the expansion board or the expansion unit to perform a part or all of the actual operations based on instructions of the program code. 
     While the present invention has been described with reference to an exemplary embodiment, it is to be understood that the invention is not limited to the disclosed exemplary embodiment. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures and functions. 
     This application claims priority from Japanese Patent Application No. 2008-127391 filed May 14, 2008, which is hereby incorporated by reference herein in its entirety.