JP2018036810A - Device server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shift a plurality of connected peripheral devices to a suspension state efficiently, open a session with a client device keeping the connection when a specific condition is satisfied, and make the peripheral devices available from other client device.SOLUTION: A device server is directly or indirectly connected to peripheral devices 4 and 5, and relays between client devices 2 and 3 and the peripheral devices via a network 10. The device server comprises: a client control unit that receives information on whether or not the peripheral devices communicate with the client devices; and a device control unit that, when the peripheral devices do not communicate with any of the client devices, notifies the peripheral devices so as to shift to a suspension state, and when all of the connected peripheral devices do not communicate with the client devices at an arbitrary port, suspends a bus power supply to the port.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a device server in a peripheral device control system in which a client device uses a peripheral device via a network.

  In recent years, with the spread of networks, computer peripheral devices (hereinafter also referred to as peripheral devices) such as MFPs (Multi Function Peripherals) and scanners are connected to the network, and a plurality of client devices (for example, personal computers, tablets, etc.) are connected to the network. In response to the desire to use these computer peripheral devices, an apparatus called a device server has become widespread (Non-Patent Document 1).

  When using the device server and using a peripheral device on the network from the client device, software (hereinafter also referred to as a virtual connection tool) for controlling the device server operating on the client device is used to connect the device server. You can select and connect a connected peripheral device. As a result, the user of the client device can use the selected peripheral device as if it was directly connected to the client device.

  On the other hand, in the USB (Universal Serial Bus) standard, a state of suspend is defined, and it is possible to reduce the power consumption of a USB device connected to a client device with a USB cable. This is a specification that if no signal is detected on the signal bus for at least 3 milliseconds, the USB device must enter a suspended state such as temporarily stopping the running software or the active device. is there.

  Here, a suspend specification cannot be realized in a system in which a USB device and a client device are connected via a network such as the device server system. That is, since there is no direct electrical connection between the client device and the USB device, which is a condition for shifting to suspend, it is difficult to realize suspend in the system. That is, the USB device locally connected to the device server continuously consumes power when it is powered by the USB bus power from the device server (powered through the USB cable).

  To reduce the power consumption of the USB device in the device server system, when the USB device is in a standby state, the bus power supply to the USB device is turned off, and the USB bus power is turned on in response to a command request from the client device to supply power A device server is disclosed (see Patent Document 1). As another approach, the power consumption of the USB device is suppressed by, for example, shifting the USB device to a suspended state when the client device is turned off (shut down) (see Patent Document 2). It has been broken.

JP 2007-310796 A JP2012-014343A

Silex Technology, Inc., SX-DS-3000WAN <http://www.silex.jp/products/catalog/sxds3000wan.pdf>

  However, in a system using a device server, even though client devices that exist on the network do not use all devices connected to the device server, these unused devices are suspended (power saving). State) and continue to consume power. In addition, there is another problem that if the client device is left suspended while occupying the USB device connected to the device server, another USB device cannot be used from another client device. Are not in Patent Document 1 and Patent Document 2.

  The present invention has been made in view of the above-described problems, and efficiently suspends a plurality of USB devices connected to a device server and suppresses power consumption. In addition, the client device can use the USB device from another client device even when the device is suspended while maintaining the connection (session) with the USB device connected to the device server. Objective.

  In order to solve the above problems, a device server according to an aspect of the present invention is a device server that is directly or indirectly connected to a peripheral device and relays between a client device and the peripheral device via a network, A client control unit that receives information on whether or not a peripheral device is communicating with a client device and a power supply management unit, and (1) the peripheral device is not communicating with any client device , Notify the peripheral device to transition to the suspended state, and (2) if any connected peripheral device is not communicating with the client device at any port, A power supply management unit that determines to stop bus power supply.

  According to this, when the client device is not communicating with the peripheral device, the device server shifts the peripheral device to the suspend state, and all the peripheral devices connected to arbitrary ports are connected to the client device. When communication is not performed between the two, unnecessary power consumption is suppressed by stopping bus power feeding.

  Note that the term “peripheral device is directly or indirectly connected to the device server” means that the peripheral device is directly connected to the port of the device server or indirectly connected via a USB hub or the like. Including meaning.

  In order to solve the above problems, a device server according to an aspect of the present invention is a device server that is directly or indirectly connected to a peripheral device and relays between a client device and the peripheral device via a network, A client control unit that receives information on whether or not a peripheral device is communicating with a client device and a power supply management unit, and (1) the peripheral device is not communicating with any client device , Notify the peripheral device to transition to the suspend state. (2) At any port, all connected peripheral devices are not communicating with the client device and are connected to the port. When any of the peripheral devices satisfies the first predetermined condition, it is determined that the bus power supply to the port is stopped. A device server and a power supply controller. Here, the first predetermined condition is a peripheral device that allows bus power supply to be stopped in the suspended state.

  According to this, when the client device is not communicating with the peripheral device, the device server shifts the peripheral device to the suspended state, and all the peripheral devices connected to arbitrary ports are connected to the client device. If any of the peripheral devices connected to the port are not communicating with the client device and permitting the bus power supply to be stopped when not communicating with the client device, By stopping bus power feeding, unnecessary power consumption is suppressed.

  In addition, the device server according to one aspect of the present invention includes a client control unit that receives a notification from the client device that has performed communication with an arbitrary peripheral device that the client device transitions to the power saving mode. In addition, the device control unit receives the notification that the client control unit transitions to the power saving mode from the client device, and when the power supply management unit determines that the second predetermined condition is satisfied, Release the session with the peripheral device that was communicating with the client device.

  According to this, when the device server receives a notification from the client device that has been communicating with an arbitrary peripheral device that the client device transitions to the power saving mode and satisfies a predetermined condition. The session between the client device and the peripheral device that was communicating with the client device can be released. In this way, the peripheral device transitions to the suspended state, and the client device is not communicating with the peripheral device, but the session is maintained and the peripheral device cannot be used from another client device. Can be avoided. Further, when the session is continuously maintained as in the prior art, communication can be started immediately with the client device that has returned from the power saving mode.

  Further, the second predetermined condition is that the peripheral device that has been communicating with the client is a peripheral device that allows the session with the client device to be released when the client device transitions to the power saving mode.

  The present invention enables a device that is suspended while maintaining a connection (session) with a client device to be used from another client device while suppressing power consumption of the device connected to the device server in the device control system. .

FIG. 1 is an overall view of a device control system according to an embodiment of the present invention. FIG. 2 is a hardware configuration of the device server according to the embodiment of the present invention. FIG. 3 is a functional block diagram of the device server according to the embodiment of the present invention. FIG. 4 is an example of functional blocks of the client device according to the embodiment of the present invention. FIG. 5 is a flowchart from when the device server according to the embodiment of the present invention confirms the usage status of a device connected to the own device to when the power supply for each port is stopped. FIG. 6 is a flowchart from receiving notification from the client apparatus according to the embodiment of the present invention until the device server releases the session with the device connected to the own apparatus.

  Hereinafter, embodiments will be specifically described with reference to the drawings.

  Numerical values, constituent elements, arrangement positions of constituent elements, and the like shown in the following embodiments are merely examples, and various modifications and changes can be made within the scope of the invention.

(Embodiment)
FIG. 1 is an overall view of a device control system according to an embodiment of the present invention.

  As shown in FIG. 1, a device control system 100 according to an embodiment of the present invention includes a device server 1, a client device 2, a client device 3, a USB hub 4, a USB device 5, a LAN (Local Area Network) 10, and the like. Is done. The client device 3 has the same function as the client device 2, and the detailed description will be given only to the client device 2 hereinafter.

  In the device control system 100, the device server 1, the client device 2, and the client device 3 are network-connected via a LAN 10.

  The device control system 100 can communicate with a device connected to the device server 1 via the LAN 10 according to an instruction from an application provided in the client device 2 or the client device 3. The LAN 10 will be described on the premise of a wired LAN in the embodiment of the present invention, but may be a wireless LAN.

  The device server 1 includes a USB interface. The device server 1 may include one USB interface or two or more USB interfaces. Further, the device server 1 includes a network interface, and the network interface may include both a wired communication interface and a wireless communication interface, or may include either one of the interfaces. The wired communication interface is an interface that performs communication conforming to, for example, the IEEE 802.3 standard. The wireless communication interface is an interface that performs communication conforming to, for example, the IEEE 802.11 standard.

  In FIG. 1, the device server 1 has two ports, a USB hub 4 is locally connected to the first port, and a small scanner or a portable hard disk is connected to the port of the USB hub 4 with a USB cable. ing. A USB device 5 (for example, a mobile printer) is directly connected locally to the second port. The peripheral device connected to the port of the USB hub 4 with a USB cable is a device that is driven by USB standard bus power.

  The device server 1 is connected to the peripheral device connected to the device server 1 via the LAN 10 based on an instruction from the application of the client device 2 (for example, a device indirectly connected via the USB hub 4, And a directly connected USB device 5 or the like can be selected and connected or disconnected (session establishment or session release). As a result, the user of the client device can use the peripheral device selected and connected over the network as if it were directly connected to the client device.

  The client device 2 is, for example, a PC (Personal Computer), a tablet terminal, a mobile communication terminal, or the like. The client apparatus 2 includes an application (hereinafter referred to as a connection management tool) that realizes that at least the peripheral device selected over the network can be used as if it was directly connected to the client apparatus. The client device 2 includes a network interface for communicating with the device server 1, and the network interface may include both a wired communication interface and a wireless communication interface, or one of the interfaces. May be.

  The USB hub 4 is a device that conforms to the USB standard and relays between a client device and a USB device. The USB hub 4 includes at least one port for locally connecting a USB device, and the USB device can be locally connected to each port. The USB hub 4 is a device for using a plurality of USB devices by using one port of a device (for example, the device server 1) to which the USB hub 4 is connected. The device control system of FIG. In 100, the client apparatus 2 can use a device having more than the number of ports provided in the device server 1 via the device server 1. Further, the USB hub 4 of the present embodiment receives bus power from the port of the device server 1 and supplies bus power to the connected device.

  The USB device 5 of the present embodiment is a USB device that can be driven by being supplied with power by USB bus power in accordance with the USB standard. For example, a mobile printer, a portable scanner, a portable hard disk, a USB memory, a mouse, a keyboard, a card reader, and the like.

  FIG. 2 is a hardware configuration diagram of the device server 1 and the client device 2 according to the embodiment of the present invention. The client device 3 has the same hardware configuration as that of the client device 2 and will not be described in detail later.

  As shown in FIG. 2, these devices include a CPU (Central Processing Unit) 20, a ROM (Read Only Memory) 21, a RAM (Random Access Memory) 22, a storage device 23, a USB-I / F 24, a WNIC (Wireless Network Interface). Card) 25, NIC (Network Interface Card) 26, and an internal bus 27 for connecting the components. The device server 1 and the client device 2 do not necessarily have the WNIC 25.

  The CPU 20 is a processor that executes a control program stored in the ROM 21.

  The ROM 21 is a read-only storage area that holds a control program and the like.

  The RAM 22 is a storage area used as a work area used when the CPU 20 executes a control program.

  The storage device 23 is a storage area for temporarily storing control programs, control information, device information, or information.

  The USB-I / F 24 has a connector (hereinafter also referred to as a port) conforming to the USB standard, and performs communication control with a USB device connected to the connector.

  The WNIC 25 is a wireless communication interface that performs wireless communication. For example, a wireless LAN communication interface conforming to the IEEE802.11a, b, g, n, and ac standards.

  The NIC 26 is a wired communication interface that performs wired communication. For example, a wired LAN communication interface conforming to the IEEE 802.3 standard or the like.

  The internal bus 27 is a bus that electrically connects the CPU 20, ROM 21, RAM 22, storage device 23, USB-I / F 24, WNIC 25, and NIC 26 to exchange signals.

  FIG. 3 is a functional block diagram of the device server 1 according to the embodiment of the present invention.

  The device server 1 illustrated in FIG. 3 includes a client control unit 31, a device control unit 32, a communication control unit 33, a power supply management unit 34, and the like.

  Based on the communication status from the device control unit 32, the client control unit 31 determines whether all devices connected to the port of the own device are communicating with the client device 2 (during communication). Then, the result is notified to the power supply management unit 34. Here, the communication status is information such as “communicating (during communication)”, “not communicating (non-communication)”, and the like. For example, the communication status “communication (communication in progress)” means that the client apparatus 2 is transmitting / receiving data to / from the device via the device server 1 or for communication control. This is a situation where commands are transmitted and received.

  Further, the client control unit 31 notifies the power supply management unit 34 of the communication status at a predetermined time. Here, the predetermined time for notifying the power supply management unit 34 of the communication status may be, for example, a fixed time interval after the device server 1 is turned on, or from the resident module 42 provided in the client device 2. The device control unit 32 may receive an instruction or an instruction given by the user from the application 41.

  Furthermore, the client control unit 31 determines whether or not a power saving mode notification from the client device 2 has been received. In addition, the client control unit 31 transmits and receives network packets to and from the communication control module 46 of the client device 2 through the LAN 10.

  The device control unit 32 notifies the client control unit 31 of the communication status of the device connected to the port of the own device.

  In addition, the device control unit 32 receives a suspend notification (described later) from the power supply management unit 34 and controls to suspend the device.

  Furthermore, the device control unit 32 receives the notification that the power supply from the power supply management unit 34 is stopped, and stops the power supply (by bus power) to the port included in the device.

  In addition, the device control unit 32 receives a notification from the power supply management unit 34 as will be described later, and controls peripheral devices that have established a session with the client apparatus 2 so as to release the session.

  The communication control unit 33 has a function equivalent to a tunneling driver 45 of the client apparatus 2 to be described later, and is a data format that can transmit a network packet received by the client control unit 31 to a peripheral device connected via the device server 1 To the device control unit 32. On the other hand, the peripheral device data received by the device control unit 32 is converted into a data format that can be transmitted to the client device 2 and passed to the client control unit 31.

  When there is a device that is not communicating with the client apparatus 2 based on the notification from the client control unit 31, the power supply management unit 34 notifies the device control unit 32 to change the device to suspend (hereinafter referred to as a suspend notification). )I do.

  In addition, the power supply management unit 34 determines whether or not a condition for stopping the bus power supply is satisfied with respect to the port provided in the own device. When this condition is satisfied, the device control unit 32 is notified that power supply to the port is stopped. This condition can be set for each port or device. The setting for each port is that when all devices connected to a certain port transition to the suspended state, the bus power supply to the port is stopped. On the other hand, the setting for each device is that all devices connected to a certain port transition to the suspend state and all devices “allow bus power supply stop when in suspend state” (first predetermined condition) In this case, the bus power supply to the port is stopped. (Conversely, if at least one device does not accept the bus power supply stop, the bus power supply continues even if all devices are in the suspended state.)

  From the viewpoint of power saving, it is desirable to stop the supply of bus power to the device that has transitioned to the suspended state. However, there is a demerit such as a device that takes time to start up or initialization processing as the bus power supply resumes or the client device and its connection (session) return. Therefore, in the present invention, after shifting to the suspend state, the bus power supply is not forcibly stopped, but the device or the port has a degree of freedom of whether or not to allow the supply stop. By doing in this way, the balance of a user's convenience and power saving can be obtained suitably.

  Furthermore, the power supply management unit 34 releases the session with the client device 2 for each device based on the power saving mode notification from the client device 2 and the session release condition (also referred to as a second predetermined condition). Judge whether it is good or not. When the release is permitted, the device control unit 32 is notified to the device that the session is to be released. This condition is set for each device. In a device (for example, a printer) that is used by a large number of clients, when the use is finished, it is preferable to once release the session so that it can be used by any client, but on the other hand, use it again from the original client. In this case, it is necessary to install the driver by operating the plugged play again, and there is a demerit that it takes time until reuse. Therefore, a session release condition is set for each device, which further enhances user convenience.

  FIG. 4 is a functional block diagram of the client device 2 according to the embodiment of the present invention.

  4 includes an application 41, a resident module 42, a device driver 43, a USB class driver 44, a tunneling driver 45, a communication control module 46, and the like that are stored in the ROM 21 or the storage device 23 and expanded in the RAM 22 at the time of execution. As a software component. In addition, there is an OS (Operating System) as a software component, which is stored in the ROM 21 and the storage device 23 together with various data necessary for control. These software components and various data are read out on a memory such as the RAM 22 according to the control of the CPU 20, and various controls are executed.

  The application 41 is software installed in the client apparatus 2, and is connected when communicating with a device 5 or a USB hub 4 (hereinafter also referred to as a peripheral device) connected to the device server 1 via the LAN 10. Establishment) and disconnection (release the session). Specifically, the application 41 is a virtual connection tool that controls connection / disconnection of a peripheral device when using the peripheral device connected to the device server 1 via the LAN 10 from the client apparatus 2. By using this tool, the user of the client apparatus 2 can use the selected peripheral device as if it were directly connected to the client apparatus 2.

  The application 41 notifies the resident module 42 of a connection or disconnection instruction with a peripheral device performed by a user using the client apparatus 2.

  The resident module 42 is a software component that always stands by and operates while the OS is running, and performs data transmission and reception with the device server 1 via the LAN 10. Also, USB device information for recognizing and identifying peripheral devices connected to the device server 1 is received. Based on the received USB device information, a device driver 43 and a USB class driver 44 necessary for data transmission / reception with the peripheral device are generated, and the peripheral device can be controlled.

  The resident module 42 constantly monitors the communication status (for example, during communication, no communication, etc.) between the client device and the device server. Also, the power usage status of the client device is acquired from the OS. For example, there are a sleep state, a hibernation state, a mode in which power is not consumed as much as possible in a power management tool, etc. (hereinafter referred to as a power saving mode).

  Furthermore, the resident module 42, when the client device has transitioned to the power saving mode, notifies the client control unit of the device server 1 via the LAN 10 that the client device has switched to the power saving mode (hereinafter referred to as the power saving mode notification). 31.

  The device driver 43 converts a data input / output request from a higher-level program such as the OS, the application 41, and the resident module 42 into a data format corresponding to the peripheral device targeted for data input / output, and sends a response from the peripheral device to the higher-level program To pass.

  The USB class driver 44 converts the data input / output request converted into the data format according to the peripheral device by the device driver 43 into packet data compliant with the USB data format and passes it to the tunneling driver 45. The packet data conforming to the USB data format sent from 45 is converted into a data format and passed to the device driver 43.

  The tunneling driver 45 encapsulates the USB packet data passed from the USB class driver 44 into a network packet so that it can communicate with the device server 1 via the LAN 10. On the other hand, when a network packet is received from the device server 1, USB packet data is taken out (decapsulated) from the network packet and passed to the USB class driver 44 and the device driver 43.

  The communication control module 46 receives a network packet from the tunneling driver 45 of the host program and transmits it to the client control unit 31 of the device server 1 via the LAN 10. On the other hand, when a network packet is received from the device server 1 via the LAN 10, the network packet is passed to the tunneling driver 45.

  FIG. 5 shows the flow from when the device server according to the embodiment of the present invention confirms the usage status of a device connected to its own device to when the power supply for each port is stopped, in the following order. explain.

  In step S500, the device control unit 32 notifies the client control unit 31 of the communication status of the device connected to one of its own ports. Based on the communication status, the client control unit 31 determines whether the device is communicating with the client apparatus 2 (during communication) and notifies the power supply management unit 34 of the result. When the device and the client apparatus 2 are communicating, the process proceeds to step S502 (Yes in step S500). If not communicating, the process proceeds to step S501 to suspend the device (No in step S500).

  In step S501, based on the notification from the client control unit 31 (No in step S500), the power supply management unit 34 notifies the device control unit 32 so that the device transitions to the suspended state. Upon receiving the suspend notification from the power supply management unit 34, the device control unit 32 performs processing for transitioning the device to the suspend state according to the USB standard.

  In step S502, the device control unit 32 determines whether or not the client control unit 31 has been notified of the communication status of all devices connected to one of the ports of the own device. If notified, the process proceeds to step S503 (Yes in step S502). If not notified, the process proceeds to step S506 (No in step S502).

  In step S503, the power supply management unit 34 determines whether a condition for stopping the bus power supply is satisfied. When it is satisfied, the device control unit 32 is notified that the power supply to the device directly or indirectly connected to the target port is stopped (Yes in step S503). When not satisfy | filling, it changes to step S505 (No of step S503). As described above, the conditions for stopping the bus power supply are as follows: (a) All devices connected directly or indirectly to the target port have transitioned to the suspended state, or In the control, (b) all devices connected directly or indirectly to the target port have transitioned to the suspend state, and all devices have stopped the bus power supply in the first predetermined condition, ie “suspend state. It means that the setting is “good”. That is, the first setting condition may be set in advance at the time of shipment from the factory, or may be set from an application provided in the client device.

  In step S504, upon receiving a notification from the power supply management unit 34 (Yes in step S503), the device control unit 32 stops supplying bus power to the port.

  In step S <b> 505, the client control unit 31 determines whether a series of processing from step 501 to step S <b> 504 has been executed based on the communication status from the device control unit 32 for all ports provided in the own device. To do. If a series of processing has been performed for all ports, the processing ends (Yes in step S505). If a series of processing has not been performed, the process proceeds to step S507 (No in step S505).

  In step 506, the client control unit 31 includes devices connected to one target port (including devices connected indirectly through a USB hub) based on the communication status from the device control unit 32. In order to repeat the series of processes in steps S500 to S502, a series of processes is started for devices that have not been processed.

  In step 507, the client control unit 31 repeats the series of processing from step S500 to step S505 for all the ports sequentially based on the communication status from the device control unit 32, and thus the processing is not completed. A series of processing is started for the port.

  Here, the timing for performing a series of processing for a plurality of ports provided in the device server 1 is executed at a predetermined time interval after the device server 1 is powered on, for example. Further, it may be executed based on an instruction from a resident module provided in the client device 2 or an instruction from an application performed by a user. In particular, the device server 1 can perform a series of processing at a predetermined time interval, and thus can perform a series of processing autonomously without receiving an instruction from the client device 2 or an instruction to an application performed by the user. It is possible to suppress labor and unnecessary power supply.

  Next, FIG. 6 shows the operation of the client apparatus and the device in the flow from receiving the notification from the client apparatus according to the embodiment of the present invention until the device server releases the session with the device connected to the own apparatus. The operation of the server will be described below along the flow of processing. At the time of starting the processing in FIG. 6, the client device 2 and the device 5 connected to the own device are in a state in which they can communicate with each other by the application 41 provided in the client device 2 (a session is established), The resident module 42 constantly monitors each other's communication status (for example, during communication, no communication, etc.).

  In step S601, the resident module 42 provided in the client device 2 determines whether information indicating that the client device 2 has transitioned to the power saving mode has been acquired from a system (not shown, for example, an OS). When transitioning to the power saving mode, transition is made to step S602 (Yes in step S601). If the mode has not been changed to the power saving mode, the process stays in step S601 and waits for acquisition of information indicating that the system has changed to the power saving mode (No in step S601).

  In step S <b> 602, the resident module 42 included in the client device 2 notifies the device server 1 via the LAN 10 of information that “the own device (client device 2) has shifted to the power saving mode”. The power saving mode notification is converted into a format communicable with the device server 1 by the tunneling driver 45, and notified to the device server 1 from the communication control module 46 through the LAN 10.

  In step S <b> 603, the client control unit 31 included in the device server 1 determines whether or not a power saving mode notification is received from the client device 2. If it has been received, this is notified to the power supply management unit 34, and the process proceeds to step S604 (Yes in step S603). If not received, step S603 is repeated to wait for reception of the power saving mode notification (No in step S603).

  In step S604, the power supply management unit 34 determines whether or not the session with the client apparatus 2 may be released based on the power saving mode notification from the client apparatus 2 and the session release condition. When the session release is permitted, the device control unit 32 is notified to the device related to the client 2 that the session is released, and the process proceeds to step S605 (Yes in step S604). If session release is not permitted, the process proceeds to step S606 (No in step S604). Here, the session release condition is a condition for releasing a session between the client apparatus 2 and the device 5 when the client control unit 31 of the device server 1 receives the power saving mode notification from the client apparatus 2. The session release condition may be set in advance for each device in the device server 1 or may be set by the application 41 provided in the client apparatus 2.

  In step S605, the power supply management unit 34 notifies the device control unit 32 that the session between the client apparatus 2 and the device 5 is to be released based on the determination in step S604 (Yes in step S604). The control unit 32 performs control so that the device 5 releases the session with the client apparatus 2 and shifts to the suspend state. In this way, since the session between the client apparatus 2 and the device 5 is released by another client apparatus (for example, the client apparatus 3) that wants to newly use the device 5, the application 41 of the client apparatus 3 By making a connection request to the suspended device 5, the session can be established immediately.

  In step S606, the power supply management unit 34 notifies that the device 5 is suspended based on the determination in step S604 (No in step S604), and the device control unit 32 causes the device 5 to transition to the suspended state. To control. That is, the device 5 transitions to the suspended state while maintaining the session with the client device 2. In this way, while other clients cannot use the device 5, the session between the client 2 and the device 5 is maintained, so communication with the client device 2 immediately after returning from suspend. Can be resumed.

(Summary)
As described above, in the device control system that relays between the client device and the device connected to the port of the own device via the network, the device server according to the embodiment of the present invention is the client device. If the device is not communicating with the device, the device can be put into suspend, and if the bus power (power from the device server to the device) can be stopped, stop the bus power. Reduce unnecessary power consumption. Further, when a notification that the client apparatus has shifted to the power saving mode is received from the client apparatus via the network, it is determined whether to release the session between the client apparatus and the device or to maintain the session. In this way, while the device transitions to one power saving mode and is not communicating with the device, the session is maintained and the client device cannot be used from another client device. If it is determined that the session is to be maintained as in the prior art, communication can be started immediately with the client device that has returned from the power saving mode.

  This is useful for smoothly using the device in the system while suppressing unnecessary power consumption due to the suspended state of the USB device.

100 Device control system 1 Device server 2, 3 Client device 4 USB hub 5 Device (printer)
10 LAN
20 CPU
21 ROM
22 RAM
23 Storage device 24 USB-I / F
25 WNIC
26 NIC
27 Internal Bus 31 Client Control Unit 32 Device Control Unit 33 Communication Control Unit 34 Power Supply Management Unit 41 Application 42 Resident Module 43 Device Driver 44 USB Class Driver 45 Tunneling Driver 46 Communication Control Module

Claims (4)

A device server that is directly or indirectly connected to a peripheral device and relays between a client device and the peripheral device via a network;
A client control unit for receiving information on whether or not a peripheral device is communicating with the client device;
A power management unit,
(1) If the peripheral device is not communicating with any client device, notify the peripheral device to transition to the suspended state,
(2) In any port, when all the connected peripheral devices are not communicating with the client device, it is determined to stop the bus power supply to the port.
A device server comprising a power supply management unit.
A device server that is directly or indirectly connected to a peripheral device and relays between a client device and the peripheral device via a network;
A client control unit for receiving information on whether or not a peripheral device is communicating with the client device;
A power management unit,
(1) If the peripheral device is not communicating with any client device, notify the peripheral device to transition to the suspended state,
(2) When any peripheral device connected at any port does not communicate with the client apparatus, and any peripheral device connected to the port satisfies the first predetermined condition Judging to stop the bus power supply to the port.
A power supply management unit,
The first predetermined condition is a device server that is a peripheral device that allows bus power supply to be stopped in a suspended state.
The device server is
A client control unit that receives a notification from the client device that has been communicating with an arbitrary peripheral device that the client device transitions to the power saving mode;
The device controller is
When the power supply management unit determines that the client control unit receives a notification from the client device that the mode is changed to the power saving mode and satisfies a second predetermined condition, the client device, the client device, The device server according to claim 1, wherein a session with the peripheral device that has performed communication is released.
The second predetermined condition is that the peripheral device that is communicating with the client is a peripheral device that allows a session with the client device to be released when the client device transitions to a power saving mode. ,
The device server according to claim 3.