JP2004048532A - Network interface unit, power control method, computer readable storage medium and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To save total power consumption of a network system furthermore by making the power state in a network interface unit transit freely from normal state to power saving state or vice versa. <P>SOLUTION: In a network system where a main apparatus being attached with an interface unit can communicate with another apparatus through a network, a signal detecting section 7 monitors a packet signal for the main apparatus being filtered through a switching hub 10, and a clock control section 8 controls a clock frequency being fed to the CPU section 4 of the network interface unit to increase or decrease. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an interface device having a CPU unit for connecting to a local area network and communicating with other devices, a power control method, a computer-readable storage medium, and a program.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, main units such as printers (including printers, copiers, faxes, scanners, copiers, personal computers, etc.) are connected to a local area network (LAN) such as Ethernet (registered trademark) via a network interface device. In the system, as a target of power saving, control mainly focused on the main device was performed.
[0003]
The reason is that the network interface device communicates the status of the main unit with the host on the network, and sets and cancels the power saving state of the main unit based on communication information from the host on the network. If the device itself enters the power saving state, communication with the host via such a network becomes impossible, and the network interface device is exceptionally excluded from the target of power saving.
[0004]
Further, it is assumed that the conventional network interface device is connected to various hubs, and a packet monitoring function has been constructed so as to support both a repeater hub and a switching hub.
[0005]
[Problems to be solved by the invention]
However, the above conventional example has the following problems.
[0006]
In recent years, further energy saving has been demanded in consideration of the environment, and it is inevitable that main units such as printers must comply with power saving standards.
[0007]
Under these circumstances, not only in the main unit but also in the devices connected to the main unit such as a network interface device, the demand for power saving in conjunction with global warming countermeasures is not limited to only a part of the device, but the entire device. The demand is growing.
[0008]
In addition, the conventional network interface has a packet monitoring function even when the device is connected to a switching hub that is expected to transmit fewer packets to the network interface than when a repeater hub is used. Was performed in the same way as that of the repeater hub, and was performing useless high-speed processing.
[0009]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a network system in which an interface device can be mounted on a main device and another device can communicate with each other via a network. By monitoring the packet signal and raising or lowering the clock frequency supplied to the CPU unit of the interface device, the power state inside the interface device can be freely changed from the normal state to the power saving state, or from the power saving state to the normal state. Another object of the present invention is to provide a network system, a power control method, a computer-readable storage medium, and a program that can further reduce power consumption of the entire network system.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a network interface device provided in an image forming apparatus connected to an information processing apparatus via the apparatus, wherein the monitoring means monitors a packet communicated via the apparatus. It has a network controller unit 3) in FIG. 1 and a control unit (CPU unit 4 in FIG. 1) that controls so as to reduce the power used by the monitoring unit according to the type of device to be connected. And
[0011]
A second invention according to the present invention is characterized in that when it is determined that the device is a repeater concentrator, the power consumption of the monitoring means is not reduced.
[0012]
A third invention according to the present invention is characterized in that, when the device is a concentrator having a filter function, the control means performs control so as to reduce power consumption used by the monitoring means. .
[0013]
A fourth invention according to the present invention has a detecting means (signal detecting unit 7 in FIG. 1) for detecting a packet signal for performing information communication on the network, and the control means comprises a packet detecting means for detecting a packet signal detected by the detecting means. It is determined whether or not a signal is detected within a predetermined time (CPU unit 4 in FIG. 1). If it is determined that no packet signal is detected within a predetermined time, the power consumption used by the monitoring means is reduced. (CPU unit 4 in FIG. 1).
[0014]
A fifth invention according to the present invention is characterized in that the predetermined time can be variably set by a command from the another device.
[0015]
A sixth invention according to the present invention is characterized in that the monitoring means includes a CPU, and the control means instructs to reduce the operating frequency of the CPU.
[0016]
A seventh invention according to the present invention is a power control method by a network interface device provided in an image forming apparatus, which is connected to an information processing apparatus via the apparatus, wherein a packet communicated via the apparatus is provided. A monitoring step (step (5) in FIG. 3) for monitoring
A control step (steps (2) to (11) in FIG. 3) for controlling so as to reduce the power used by the monitoring means in accordance with the type of the connected device.
[0017]
According to an eighth aspect of the present invention, when the device is determined to be a repeater concentrator, the power consumption in the monitoring step is not reduced (determined as No in step (2) of FIG. 3). ).
[0018]
According to a ninth aspect of the present invention, when the device is a concentrator having a filter function (Yes in step (2) of FIG. 3), the control step reduces power consumption used in the monitoring step. It is characterized in that it is controlled so as to reduce it.
[0019]
A tenth invention according to the present invention has a detecting step of detecting a packet signal for performing information communication on the network, wherein the control step detects the packet signal detected by the detecting step within a predetermined time. It is determined whether or not there is any packet signal (step (9) in FIG. 3), and if it is determined that no packet signal is detected within a predetermined time, control is performed so that the power consumption used in the monitoring step is reduced (FIG. 3). 3 (10)).
[0020]
An eleventh invention according to the present invention is characterized in that the predetermined time can be variably set by a command from the another device.
[0021]
A twelfth invention according to the present invention is characterized in that the monitoring means includes a CPU, and the control means instructs to reduce the operating frequency of the CPU.
[0022]
A thirteenth invention according to the present invention is a computer-readable storage medium storing a program for implementing the power control method according to any one of the seventh to twelfth inventions.
[0023]
A fourteenth invention according to the present invention is a program executed by an information processing device for realizing the power control method according to any one of the seventh to twelfth inventions.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
FIG. 1 is a diagram illustrating a configuration of a network system to which an interface device according to a first embodiment of the present invention is applied, and corresponds to, for example, an example of a network system in which a printer device includes an interface device.
[0025]
It is needless to say that the present invention can be applied to an interface device alone and a device to which the interface device can be mounted, for example, a digital multifunction peripheral, a network scanner printer, a network scanner, a facsimile device, and the like.
[0026]
In the figure, reference numeral 1 denotes a network interface device, which enables a main unit such as a printer to be connected to a network. A transceiver unit 2 is physically connected to a network and corresponds to a physical layer in the OSI reference model.
[0027]
Reference numeral 3 denotes a network controller which controls communication with the network, and corresponds to a link layer in the OSI reference model. Although not shown, a determination means for determining whether or not the finally received packet is addressed to the own device is provided in hardware or software.
[0028]
A CPU 4 controls the network interface device 1. A device I / F 5 performs data communication with a main body such as a printer device. As a device to which the network interface device 1 can be attached and detached, a facsimile device, a digital copier, a digital multifunction device, and the like are assumed in addition to a printing device (printer) that employs an electrophotographic system or an inkjet system.
[0029]
Reference numeral 6 denotes a memory unit for storing a program for operating the CPU unit 4 and temporary data. The CPU unit 4 includes a so-called CPU and ROM, and executes a control program stored in the ROM to perform network communication control.
[0030]
Reference numeral 7 denotes a signal detection unit that detects a signal on the network. A clock control unit 8 controls the frequency of a clock signal to the CPU unit 4 based on a signal from the signal detection unit 7 and control information from the CPU unit 4.
[0031]
Reference numeral 15 denotes a sleep monitoring timer unit that monitors a time until a transition to sleep set by the CPU unit 4 or the clock control unit 8. The time before the transition to the sleep can be set arbitrarily based on a command from the main device or a host device on the network.
[0032]
FIG. 2 is a diagram showing an example of a network system to which the interface device according to the present invention can be applied.
[0033]
In the figure, reference numeral 9 denotes a computer which is connected to a local area network (LAN) and communicates with the printer device 11 via the network interface device 1.
[0034]
Reference numeral 10 denotes a hub (concentrator), for example, in the case of a switching hub, filters communication packets on a network. Further, a case of a repeater hub having a function of shaping a deteriorated portion of an input signal and simply outputting the same is also assumed. Note that the hub 10 is not limited to a switching hub or a repeater hub, and various types of hubs are assumed.
[0035]
Reference numeral 11 denotes a printer device having the network interface device 1 built in the main body. Reference numeral 12 denotes a network A, which connects the hub 10 to other devices. Reference numeral 13 denotes a network B, which connects one port of the hub 10 to the network interface device 1 on a one-to-one basis.
[0036]
Hereinafter, a normal data communication procedure using a network in the above configuration will be described.
[0037]
For example, a case will be described in which the computer 9 inquires the printer device 11 about the printer status such as the remaining amount of paper.
[0038]
To perform data transmission from the printer device 11 to the computer 9, the printer device 11 transmits information to be transmitted to the network interface device 1 via the device interface unit 5. In the network interface device 1, the CPU unit 4 receives data from the device interface unit 5 according to a program stored in the memory unit 6, temporarily stores the data in the memory unit 6, converts the data into a communication packet of a corresponding communication protocol, and then converts the data into a communication packet of a corresponding communication protocol. To the network controller 3. The network controller 3 transmits the communication packet to the computer 9 via the transceiver 2 on the network 13 at a predetermined timing. The hub 10 receives a communication packet transmitted from the network interface device 1, transmits the packet to the network 12, and the computer 9 receives the packet.
[0039]
Conversely, a case in which various commands and print data are transmitted from the computer 9 to the printer device 11 will be described.
[0040]
To transmit data from the computer 9 to the printer device 11, the computer 9 packetizes information to be transmitted and transmits the information to the network 12 to the network interface device 1. The transmitted packet is received by the network interface device 1 via the hub 10 and taken into the printer main body via the device I / F unit 5. For example, when the hub 10 is a switching hub, the network 12 is set to transfer only the communication packets addressed to the network interface device 1 to the network 13, so that the network interface device 1 receives only the packets addressed to itself. Become.
[0041]
Next, the characteristic operation of the present invention will be described.
[0042]
A communication packet is transmitted to the network 13 only when the printer device 11 transmits a communication packet onto the network via the network interface device 1 or when the hub 10 transmits a communication packet from the network 12 to the network interface device 1. It will flow. For example, a filtering function can be realized based on the MAC address (Media Access Control address) of the connected network interface device 1.
[0043]
Further, since the hub 10 and the network interface device 1 are connected in a full-duplex system, carrier detection, collision detection, and transmission of a jam signal are unnecessary, and signals other than communication packets do not flow on the network.
[0044]
The signal detection unit 7 constantly monitors a reception signal from the network 13, detects that a communication packet is flowing on the network 13, and outputs a detection signal to the clock control unit 8.
[0045]
When no communication packet flows through the communication network for a predetermined period, that is, when no detection signal is output from the signal detection unit 7, the clock control unit 8 sends an interrupt signal to the CPU unit 4 to transition to the power saving state. And the clock control unit 8 lowers the frequency of the clock signal in response to an instruction from the CPU unit 4 to cause the device to transition to the power saving state. The power saving state is, for example, a process of lowering the clock frequency of the CPU.
[0046]
Note that the period (time) from the detection of the stoppage of the communication packet to the transition to the power saving state can be set by the program as described above.
[0047]
It is also possible to change dynamically based on information transmitted from the printer device 11.
[0048]
When detecting a communication packet from the network 13 to the network interface device 1 in the power saving state, the signal detection unit 7 outputs a signal detection signal to the clock control unit 8.
[0049]
Accordingly, the clock control unit 8 causes the program to make a transition from the power saving state to the normal state by inputting an interrupt signal to the CPU unit 4. At this time, the clock control unit 8 instantaneously returns to the normal clock frequency.
[0050]
When data is sent from the printer device 11 via the device I / F unit 5, an interrupt signal is input from the device I / F unit 5 to the CPU unit 4 so that the program switches from the power saving state to the normal state. And outputs a signal to the clock control unit 8. The clock control unit 8 immediately returns to the normal clock frequency.
[0051]
FIG. 3 is a flowchart illustrating a first power control method in the network interface device according to the present invention. Note that (1) to (11) indicate each step.
[0052]
First, the CPU unit 4 acquires the connection status from the network controller unit 3 (1), and determines whether or not it is connected to the hub 10 by full-duplex Ethernet (registered trademark) (2). If it is determined that there is no Ethernet (registered trademark) in full duplex, the process returns. If it is determined in step (2) that it is a full-duplex Ethernet (registered trademark), it is recognized that it is connected to a line concentrator having a filter function such as a switching hub, and the subsequent processing is performed.
[0053]
If it is determined in step (2) that it is not connected to the full-duplex Ethernet (registered trademark), it is determined that it is connected to the repeater hub, and power saving processing such as reducing the clock frequency of the CPU is performed. Not to be. According to FIG. 3, the communication packet is not monitored when it is determined as No in the step (2). However, the normal communication packet is monitored. In other words, the process of determining whether or not the received communication packet is addressed to the own device is performed without lowering the performance of the monitoring means (by operating the CPU with normal power consumption).
[0054]
Note that the processing of step (2) is such that the network interface device and the hub directly transmit and receive information, and the network interface device inquires what type (switching hub or repeater hub) of the hub. Is also assumed. In such a case, the hub is provided with information indicating the type of the device electrically or mechanically, and the provided information can respond to an external inquiry. .
[0055]
The clock control unit 8 sets (sets) a predetermined monitoring time in the sleep monitoring timer unit 15 and starts timer counting (3). The sleep monitoring timer unit 15 can be replaced with a timer realized by a program code executable by the CPU unit 4. Then, the traffic on the network 12 is monitored (4). Then, it is determined whether a communication packet addressed to the own device is detected (5). If it is determined that the communication packet is detected, it is determined whether the current power control state is a power saving state (6). If it is determined that the state is not the power state, the process returns.
[0056]
On the other hand, if it is determined in step (6) that the state is the power saving state, the clock control unit 8 interrupts the CPU unit 4 to increase the clock frequency supplied to the CPU unit 4 (7), The state is changed from the power saving state to the normal state (8), and the process returns.
[0057]
On the other hand, if it is determined in step (5) that a communication packet addressed to the own device has not been detected, whether the sleep monitoring timer unit 15 started in step (3) has finished monitoring a predetermined monitoring time. It is determined whether or not a timeout has occurred (9). If it is determined that a timeout has not occurred, the process returns to step (3) to continue timer monitoring.
[0058]
On the other hand, if it is determined in step (9) that a time-out has occurred, the clock control unit 8 interrupts the CPU unit 4 to reduce the clock frequency supplied to the CPU unit 4 (10), Is changed from the normal state to the power saving state (11), and the process returns.
[0059]
Thus, only when connected to the switching hub by full-duplex Ethernet (registered trademark), the power consumption state of the network interface device can be timely determined with a simple configuration in which communication packets addressed to the network interface device itself are monitored for a predetermined time. Thus, it is possible to freely prepare a power control environment for easily performing a control for making a transition to the power saving state or for making a transition from the power saving state to the normal state.
[0060]
[Second embodiment]
In the above embodiment, the presence or absence of detection of a communication packet addressed to the own device is determined based on the timer counting process, and the clock frequency supplied to the CPU unit on the network is increased or decreased to reduce the power consumption of the entire network device in a timely manner. Although the case where the switching to the state or the normal state can be controlled has been described, in the second embodiment, not only the timer counting process but also a specific communication packet, for example, whether a communication packet urging an instruction to transition to the power saving state is received. The CPU unit 4 determines whether or not the clock control unit 8 raises and lowers the frequency of the clock supplied to the CPU unit 4 in the same manner as in the first embodiment, so that the same effect can be expected. May be. Hereinafter, the embodiment will be described.
[0061]
FIG. 4 is a block diagram illustrating a configuration of a network interface device according to a second embodiment of the present invention, and the same components as those in FIG. 1 are denoted by the same reference numerals.
[0062]
The difference from the first embodiment in the configuration is that the signal detection unit 7 and the timer unit 15 are not provided. Hereinafter, features of the operation of the present embodiment will be described.
[0063]
When a communication packet for transitioning to a predetermined power saving state is received from a device such as a computer connected to the network, the CPU unit 4 instructs the clock control unit 8 to lower the clock frequency. The clock control unit 8 shifts to the power saving state by lowering the clock frequency.
[0064]
Further, upon receiving a communication packet for transition to a predetermined normal state, the CPU unit 4 instructs the clock control unit 8 to increase the clock frequency, and the clock control unit 8 increases the clock frequency. To transition from the power saving state to the normal state.
[0065]
FIG. 5 is a flowchart illustrating a second power control method in the interface device according to the present invention. Note that (12) to (21) indicate each step.
[0066]
First, the clock control unit 8 monitors traffic on the network 12 (12). Then, it is determined whether or not a communication packet for power control has been received from the own device via the hub 10 (13). If it is determined that the communication packet has not been received, the process returns to step (12).
[0067]
On the other hand, if it is determined in step (13) that a communication packet for power control has been received for the own device, then in step (14), the type of the received communication packet transits to the power saving state. It is determined whether the packet is a communication packet for performing a power saving state. If it is determined that the communication packet is a communication packet for transitioning to the power saving state, it is determined in step (21) whether the transition to the power saving state is prohibited. If the transition is prohibited, the process returns. If not, the CPU 4 instructs the clock controller 8 to lower the clock frequency (17). Makes the transition from the normal state to the power saving state by lowering the clock frequency (18), and returns.
[0068]
As a case where the transition to the power saving state is prohibited, for example, a case where a repeater hub is connected to the network interface device 1 is assumed, and the processing capacity of the CPU is reduced (supply power is reduced). One of the reasons is that it becomes impossible to monitor communication packets from the outside due to this.
[0069]
On the other hand, if it is determined in step (14) that the communication packet is not a communication packet for transition to the power saving state, it is further determined whether the communication packet is a communication packet that prohibits the transition to the power saving state, and the state is switched to the power saving state. If it is determined that the communication packet prohibits the transition, the transition to the power saving state is prohibited (20), and the process returns. If it is determined that the packet is not a communication packet that prohibits the transition to the power saving state, the CPU unit 4 instructs the clock control unit 8 to increase the clock frequency (15), and the clock control unit 8 increases the clock frequency. Then, the state is changed to the normal state (16), and the process returns.
[0070]
Thus, the network interface device itself does not perform all communication packet monitoring processing, and the computer 9 (various server devices not shown) on the network or other devices (composite digital copying machine, printer, Scanner) efficiently monitors specific communication packets transmitted from the scanner, allowing the power consumption state of the network interface device to transition to the power-saving state in a timely manner, transition from the power-saving state to the normal state, and to constantly communicate. For a network interface device that wants to operate without reducing the speed, a power control environment for easily performing control to prohibit transition to the power saving state can be provided.
[0071]
[Third embodiment]
In the above-described first and second embodiments, a hub has been described as an example of a device having a filtering function or not, but the present invention is not limited to this, and has a function similar to that of a hub. It goes without saying that the present invention is applicable to a data relay device.
[0072]
For example, routers, bridges, various servers (information processing devices), and the like are assumed to be devices replacing the hub.
[0073]
Further, although the network interface device has been described as being detachable from the printer device, the present invention is not limited to this, and application to an on-board type device having a network interface function in advance is also conceivable. In this case, a network interface unit provided in advance in the device main body is referred to as a network interface device.
[0074]
As described in the first embodiment, the apparatus is a facsimile apparatus, a digital copying machine, a digital multifunction peripheral, or a personal computer, in addition to a printing apparatus (printer) employing an electrophotographic system or an inkjet system. However, an information processing device or the like is assumed.
[0075]
Further, in the first and second embodiments, as a mechanism for reducing the power of the network interface device, the operating frequency of the CPU has been described as a mechanism. However, for example, instead of reducing the operating frequency of the CPU, another system is used. It is also assumed that the monitoring means is switched by the sub CPU (microcomputer), or that the monitoring means is operated by a secondary power supply (for example, a lithium battery).
[0076]
Hereinafter, the configuration of the data processing program that can be read by the network interface device according to the present invention will be described with reference to the memory map shown in FIG.
[0077]
FIG. 6 is a diagram illustrating a memory map of a storage medium that stores various data processing programs that can be read by the network interface device according to the present invention.
[0078]
Although not shown, information for managing a group of programs stored in the storage medium, for example, version information, a creator, and the like are also stored, and information dependent on the OS or the like on the program reading side, for example, a program is identified and displayed. Icons and the like may also be stored.
[0079]
Further, data dependent on various programs is also managed in the directory. In addition, a program for installing various programs on a computer or a program for decompressing a program to be installed when the program to be installed is compressed may be stored.
[0080]
The functions shown in FIGS. 3 and 5 in this embodiment may be performed by a host computer by a program installed from the outside. In this case, the present invention is applied even when a group of information including a program is supplied to the output device from a storage medium such as a CD-ROM, a flash memory, or an FD, or from an external storage medium via a network. Things.
[0081]
As described above, the storage medium storing the program codes of the software for realizing the functions of the above-described embodiments is supplied to the system or the apparatus, and the computer (or CPU or MPU) of the system or the apparatus stores the storage medium in the storage medium. It goes without saying that the object of the present invention is also achieved by reading and executing the program code thus obtained.
[0082]
In this case, the program code itself read from the storage medium implements the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.
[0083]
As a storage medium for supplying the program code, for example, a flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, EEPROM, or the like may be used. it can.
[0084]
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. It goes without saying that a part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0085]
Further, after the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that a CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0086]
In the above-described embodiment, the power control is performed by determining whether a command for determining whether to execute power control in the present embodiment is received by a command from the main device or a host device on the network to the interface device. It is optional to determine whether or not the execution of is possible.
[0087]
It is also optional that the command from the main device is automatically output in response to a signal indicating execution of power control by the main device.
[0088]
【The invention's effect】
As described above, according to the present invention, the power supply of the monitoring unit in the network interface unit can be reduced, and the power consumption of the entire network system can be further reduced. Was.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a network system to which a network interface device according to a first embodiment of the present invention is applied.
FIG. 2 is a diagram showing an example of a network system to which a network interface device according to the present invention can be applied.
FIG. 3 is a flowchart illustrating a first power control method in the network interface device according to the present invention.
FIG. 4 is a block diagram illustrating a configuration of a network interface device according to a second embodiment of the present invention.
FIG. 5 is a flowchart illustrating a second power control method in the network interface device according to the present invention.
FIG. 6 is a diagram illustrating a memory map of a storage medium that stores various data processing programs that can be read by the network interface device according to the present invention.
[Explanation of symbols]
1 Network interface device
2 Transceiver unit
3 Network controller
4 CPU section
5 Device I / F section
6 Memory section
7 Signal detector
8 Clock control unit
9 Computer
10 Concentrator
11 Printer device
12 Network A
13 Network B
15 Timer section

Claims (14)

A network interface device provided in an image forming apparatus connected to the information processing apparatus via the apparatus,
Monitoring means for monitoring a packet communicated via the device;
Control means for controlling so as to reduce the power used by the monitoring means according to the type of the device connected;
A network interface device comprising: 2. The network interface device according to claim 1, wherein when it is determined that the device is a repeater concentrator, the power consumption of the monitoring unit is not reduced. 3. The network interface according to claim 1, wherein when the device is a concentrator having a filter function, the control unit performs control to reduce power consumption used by the monitoring unit. 4. apparatus. Detecting means for detecting a packet signal for performing information communication on the network, wherein the control means determines whether or not the packet signal detected by the detecting means is detected within a predetermined time; 4. The network interface device according to claim 3, wherein when it is determined that no packet signal is detected, power consumption used by said monitoring means is reduced. The network interface device according to claim 4, wherein the predetermined time can be variably set by a command from the other device. 6. The network interface device according to claim 1, wherein the monitoring unit includes a CPU, and the control unit instructs to reduce an operating frequency of the CPU. A power control method by a network interface device provided in the image forming apparatus, which is connected to the information processing apparatus via the apparatus,
A monitoring step of monitoring a packet communicated via the device;
A control step of controlling so as to reduce the power used by the monitoring means according to the type of the connected device;
A power control method comprising: 8. The power control method according to claim 7, wherein when it is determined that the device is a repeater concentrator, the power consumption in the monitoring step is not reduced. 9. The power control according to claim 7, wherein, when the device is a concentrator having a filter function, the control step performs control to reduce power consumption used in the monitoring step. 10. Method. A detecting step of detecting a packet signal for performing information communication in the network, wherein the controlling step determines whether or not the packet signal detected by the detecting step is detected within a predetermined time; 10. The power control method according to claim 9, wherein when it is determined that the packet signal is not detected, the power consumption used in the monitoring step is reduced. The power control method according to claim 10, wherein the predetermined time can be variably set by a command from the other device. 12. The power control method according to claim 7, wherein the monitoring unit includes a CPU, and the control unit instructs to reduce an operating frequency of the CPU. A computer-readable storage medium storing a program for implementing the power control method according to claim 7. A program executed by an information processing apparatus for realizing the power control method according to claim 7.

Images