JPH11163912A - Device and method for network control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to restart data transmission between each node, to prevent deterioration of a data processing ability of a whole network and to enable suppression of a consumption power by enabling a remote control so that a node connected to an IEEE 1394 bus is automatically separated from the network or a user. SOLUTION: All the nodes on a network of an IEEE 1394 are equipped with a port 1, a port cut part 2, a node specification part 3 and a cut instruction control part 4. If more than 64 nodes are connected in this network, a node number excess detection circuit 5 of the node specification part 3 detects that the number of nodes connectable in the network is exceeded on the basis of information from a bus manger function part 104 or a physical layer 13 as soon as the configuration of a network bus fails and, at the same time, a node of which physical ID becomes 0 is specified. The cut instruction control part 4 controls the port cut part 2 so that this specified node is cut. Thus, it becomes possible to perform a remote control so that the node connected to the IEEE 1394 bus is separated from a user's demand or automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system in which a plurality of devices are connected to each other via a digital interface such as IEEE 1394 or the like which can synchronously transmit signals from a plurality of devices. Even if the system is configured, IE
The present invention relates to a network control device and a network control method suitable for establishing and effectively operating a system configuration without impairing the function of EE1394.

[0002]

2. Description of the Related Art In recent years, in an apparatus provided with a digital interface, in order to enable data transfer between all digital image equipment and a computer,
It is considered to adopt a unified interface method. That is, for example, the standard such as SCSI or RS232 is adopted so that it can be used not only between digital image devices but also in a computer system.

[0003] However, the transmission rate of RS232 and the like is extremely low, and it is impossible to transmit image data that requires a transmission rate of several Mbps (bits / sec) or more. Also, unlike computer data, image data needs to be transmitted in real time at a fixed period (also referred to as synchronous transmission).
32 cannot be adopted for image transmission.

[0004] Therefore, at present, the conference of the DVCR and the conference of the American TV (Advanced TV) E1A R
In 4.1, a high-speed interface method suitable for image data was studied.
hronous) IE with transfer (also called synchronous transfer) function
EE1394 High Performance Serial Bus (The Institute of Electrical and Electronics Eng.
gineers, Inc., hereinafter referred to as IEEE 1394) was adopted as post-SCSI.

[0005] The IEEE 1394 system mainly deals with the 1394 Trade Association.
ion: 1394TA) is working on standardization work and extension. At the same time, since the transmission method is capable of synchronous communication and is particularly effective for image transmission, AV equipment manufacturers are also actively participating in standardization work.

[0006] Thus, IEEE 139 is expected.
For the four systems, see Nikkei Electronics 1994.
The details are described on pages 152 to 163 of the article (Reference 1) of 7.4 (nO.612), "Comparison of three new interfaces for exploring post-SCSI design concept". As described on page 161 and subsequent pages of the same article, IEEE 1394 is based on computers, but is characterized by "it has an isochronous transfer function for multimedia." Are also effective for image data. That is,
Even if video and audio data are always transferred at regular intervals and played, there is no jerking.

Also, IEEE 1394 has a function of automatically setting a topology.
(See “Automatic Topology Setting” on pages 5 to 159.) IEEE 1394 checks the connection relationship of each device, sets the parent-child relationship between devices, and sets the I / O of each device when a device is connected, disconnected, or powered on.
The D setting and the like are reset. That is, the SCSI topology is only daisy chain, but IEEE 139
Reference numeral 4 also enables a tree configuration, and a network system can be constructed by connecting a plurality of devices. In addition, one IEEE1394 bus has
It is possible to connect up to 63 nodes.

[0008] IEEE 1394 has two types of data transfer functions.
See “Providing two types of transfer functions” on page 63). One is a normal data transfer function (referred to as asynchronous transfer), and the other is the above-described isochronous transfer function. Therefore, IEEE 1394 can mix video data of synchronous transfer and control signals of asynchronous transfer. Even when there are nodes having different maximum transmission speeds, the network system can be constructed as a network system, and furthermore, it has an excellent advantage that power can be supplied from another node via a transmission cable.

By the way, considering the case where a system is constructed by connecting a plurality of devices to a network using a wired transmission form such as IEEE 1394 which is particularly effective for image transmission as described above, 64 or more nodes are erroneously set. It is possible to connect. However, IEEE1
In the 394 system, up to 63 nodes can be connected to one bus. However, in this case, since the number of nodes exceeds the maximum number of nodes, there is a disadvantage that the original function of IEEE 1394 is impaired.

For example, when a certain node in the network system has a lower maximum transmission rate with respect to another connected node, the data transmission processing of the entire network system is caused by the data transmission function of this node. The capability is degraded, and some nodes are unable to perform the worst data transmission.

Normally, in IEEE 1394, one of a plurality of connected devices becomes a parent by performing arbitration using an automatic setting function of a topological function, and the other devices are controlled by an arbitration. The parent-child relationship between the devices is instantaneously determined to be a child. In this case, a node connected to only one device (node) is a so-called leaf node,
A node connected to one or more devices is called a branch node. As described above, the IEEE 139
Power is supplied to the controller LSIs in the physical layers of all the nodes by the transmission cables of four buses. For this reason, power is supplied to the physical layer of a node that does not transmit or receive data at all, such as the leaf node or the like, that is, there is a disadvantage that power consumption cannot be suppressed.

Therefore, when 64 or more nodes are erroneously connected as described above, the above problem can be solved if remote control can be performed so as to disconnect unnecessary nodes that do not perform data transmission from the network system. At present, the extended standard (IEEE 1394)
P1394. a Draft 1.0 document), it is only possible to control the port in the physical layer of the node by itself, thereby controlling the network system normally without impairing the function of IEEE 1394. In order to operate the
Remove the connector connected to the port of the other node,
There was a problem that it had to be disconnected from the network.

[0013]

As described above, according to the conventional network connection apparatus and network connection method, when more than 64 nodes exceeding the maximum number of connection nodes 63 are erroneously connected, according to the IEEE 1394 standard. It is possible to control an unnecessary node to be electrically disconnected by itself, but it is impossible to remotely control any node in the network system. For this reason, the unnecessary connector of the node must be disconnected by the user's hand and disconnected from the network. In addition, the data processing capability of the entire network is degraded due to the existence of a node having a slow maximum transmission rate. Further, there is a problem that power is also supplied to a leaf node that does not transmit or receive data at all, which leads to an increase in power consumption.

In view of the above, the present invention has been made in view of the above-mentioned problems, and it has been made possible to remotely control a node connected to the IEEE 1394 bus so that a user or a node can automatically disconnect the node from a network. It is an object of the present invention to provide a network control device and a network control method capable of restarting transmission, preventing deterioration of data processing capability of the entire network, and suppressing power consumption.

[0015]

A network connection device according to the present invention is provided for each device of a network in which a plurality of devices are connected in a predetermined topology via a transmission system, and is connected to the transmission system. A communication unit provided for performing communication between the plurality of devices and obtaining information necessary for the communication, a disconnection unit for electrically or logically disconnecting a connection state between the transmission system, and the communication unit Information obtained by, or device specifying means for specifying a device to be disconnected from the network based on a user request,
By controlling the disconnecting means of the device specified by the device specifying means, disconnection instruction control means capable of disconnecting the specified device from the network,
It is provided with.

In the present invention, the disconnection means is provided for each device of a network configured by connecting a plurality of devices with a predetermined topology via a transmission system, and the plurality of disconnection units are connected to the transmission system. The communication between the devices is performed, and the connection between the communication unit provided to obtain information necessary for the communication and the transmission system is electrically or logically disconnected. The device designating unit designates a device to be disconnected from the network based on information obtained by the communication unit or a request of a user, and the disconnection instruction control unit performs the disconnection of the device designated by the device designating unit. By controlling the means, the specified device can be disconnected from the network. Thereby, for example, the network is connected to IEEE1
Assuming a 394 network, this IEEE 1394
Remote control within the network becomes possible,
Even if 64 or more nodes exceed the number of connectable 63 nodes in IEEE 1394, any node can be disconnected from the network.
The network bus can be reconstructed without impairing the communication function in EE1394, and effects such as resuming data transmission can be obtained.

[0017] A network connection method according to the present invention is provided for each device of a network in which a plurality of devices are connected in a predetermined topology via a transmission system, and is provided between the plurality of devices connected to the transmission system. Disconnect processing for electrically or logically disconnecting the connection state between the communication system and the transmission system provided for obtaining information necessary for the communication while performing communication, and information obtained by the communication means, or It is possible to disconnect the specified device from the network by controlling the device specifying process for specifying a device to be disconnected from the network based on a user request and the disconnection process of the device specified by the device specifying process. And a disconnection instruction control process.

In the present invention, the disconnection process, the device designation process, and the disconnection instruction control process included in the above-described network control method are performed, for example, by the IEEE.
Since any node corresponding to a device connected to the 1394 network can be remotely controlled so as to be disconnected from the network, even if 64 or more nodes exceeding 63 nodes specified by IEEE 1394 are connected, Since an arbitrary node can be disconnected from the network, the same effect that a network bus can be reconstructed without impairing the communication function in IEEE 1394 is obtained.

[0019]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a network control apparatus employing a network control method according to the present invention. The devices shown in the figure correspond to, for example, respective nodes existing in a plurality of devices connected to a network by IEEE 1394, or some of the nodes, and constitute each embodiment of the present invention. 3 shows a configuration example of a node in a case where all necessary configuration requirements are included. Also, in each embodiment according to the present invention, an IEEE 13
The description will be made assuming that a 94 high-speed serial bus is employed.

The network controller according to the present invention, as shown in FIG. 1, for example, has a port 1 (for transmitting and receiving) which is an input / output port of a signal transmitted by a transmission system cable 17 specified by IEEE1394. Prepare. The port 1 is a physical layer 13 required to function as a node.
The input / output operation for the signal is controlled by the port disconnecting unit 2 included in the above.

The port disconnection unit 2 electrically disconnects the connection state at the port by a disconnection instruction control unit 4 that controls disconnection of the designated node in the network based on an instruction signal indicating the designated node from the node designation unit 3. So that it is controlled. That is, the node specifying unit 3 specifies the node having the port 1, and the disconnection instruction control unit 4 controls the port disconnecting unit 2 of the node specified by the node specifying unit 3 to disconnect from the network. I do.

The node designating section 3 is provided with, for example, a node number excess detecting circuit 5, a non-operating node detecting circuit 6, a transmission speed detecting circuit 7, a loop detecting circuit 11, and the like. The node specifying unit 3 is based on information from the physical layer 13, the LINK layer 15, the transaction layer 16, the bus manager function unit 14 of any one node in the network, and the like defined by the IEEE 1394 system. By using a predetermined circuit of the circuit group of (1), an instruction signal corresponding to the network connection state is obtained.

For example, the node number excess detection circuit 5 detects that the number of connectable nodes in the network (63 nodes in IEEE1394) has been exceeded, and outputs a detection result. The non-operation node detection circuit 6 detects a non-operation node (also referred to as a repeater) located at the end in the network, and outputs a detection result. In addition, the transmission speed detection circuit 7
Detects that there is a node having a different maximum transmission rate in the network, and outputs a detection result. The loop detection circuit 11 detects that a node connected in a loop exists in the network, and outputs a detection result. These detection results are provided to the above-described switching instruction control unit 4 as an instruction signal of the node designation unit 3.

It should be noted that the bus manager function unit 14
This function exists in a node determined anywhere in the network when a network bus (parent-child relationship) is constructed by bus arbitration according to the IEEE 1394 system. In addition to the bus manager function in IEEE 1394, the node generally controls the node. It includes functions such as a read controller. In other words, after the completion of the network bus construction, each bus manager function unit 14 of the node that has not become the bus manager basically operates mainly as a node controller.

On the other hand, a connection recovery circuit 8 is provided in the physical layer 13 of a node as a network control device. The connection recovery circuit 8 is for recovering the connection state disconnected by the port disconnection unit 2. Also,
The port disconnecting section 2 is provided with a connection signal disconnecting circuit 9 and a power stop circuit 12. Connection signal disconnection circuit 9
Operates to cut off the output of a signal (for example, a bias voltage from the port 1 in IEEE 1394) indicating that the connection is made to a network. By operating to shut off itself, it is logically connected but disconnects the electrical connection, that is, it can release the connection with the network, and when rebuilding the network bus , Can be recognized as a virtually non-operational node. In addition, the power supply stop circuit 1
2 operates to cut off the power supplied to disconnect a non-operational node (repeater) located at an end in the network from the network.

The display unit 10 is connected to the port disconnecting unit 2. The display unit 10 is configured by a display device such as an LED or a monitor, and can display a node disconnection state by the port disconnection unit 2 and a connection state of the entire network. Although not shown,
The disconnection instruction control unit 4 is connected to an operation unit (not shown) for allowing the user to control the disconnection of the node while watching the display on the display unit 10. Can be controlled to be disconnected.

As described above, the physical layer 13, the LINK
The layer 15 and the transaction layer 16 are IEEE 139
4, the physical layer 13 is constituted by physical means necessary for executing a communication function in the IEEE 1394 system in the network, and the LINK layer 15
It has a data communication function necessary for realizing error-free data communication between nodes in the network. Also,
The transaction layer 16 has a function capable of performing a series of processes that occur when transmitting and receiving desired data. Therefore, the bus manager function unit 14,
Physical layer 13, LINK layer 15, and transaction layer 1
6 enables the construction of a network bus and data communication in IEEE 1394.

The plurality of nodes configured as described above are connected to each other by transmission cables (cables defined by IEEE 1394) 17 via the respective ports 1 to form a network system.

In this embodiment, the port disconnecting section 2
Is required to be implemented in all nodes that can be disconnected, but the disconnection instruction control unit 4 and the node designation unit 3 need not necessarily be implemented in one node. For example, a configuration is possible in which the disconnection instruction control unit 4 is mounted on each node, but the node designation unit 3 is mounted on only one node in the network. In this case, the node designation unit 3
To give the transaction layer 16 necessary information to create it and send it to the disconnection instruction control unit 4 of the corresponding node by transmitting a control packet, thereby giving a disconnection instruction based on the instruction signal from the node designation unit 3 of the other node. Can be executed.

Next, an embodiment for solving the problems in the prior art using the network control device having the above configuration will be described in detail with reference to FIG. In each of the embodiments described below, the port disconnection unit 2, the node designation unit 3, and the disconnection instruction control unit 4 are connected to the IEEE 1
The description will be made assuming that the device is provided in a node corresponding to all devices in the 494 network.

FIG. 2 is an explanatory diagram for explaining the first embodiment of the network control method.
This shows a state in which the maximum number of connectable nodes in EEE1394 has been exceeded.

Now, it is assumed that a plurality of nodes connected to the network connection device shown in FIG. Then, as well known, IEEE 139
In 4, a network bus is constructed by performing bus arbitration. At this time, at the stage where the network configuration is determined, 0 to the physical layer 13 of each node is automatically performed by an automatic topology setting function or the like.
63 physical IDs up to 62 will be allocated. That is, as shown in FIG. 2A, when a network system having a tree structure of 63 nodes 20 to 83 is configured, 63 physical IDs are assigned to each of these nodes. Thus, the construction of the network bus is determined. At this time, any node in the network becomes a bus manager, and the node that has become the bus manager
By performing the necessary preparations for data communication according to the procedure based on the E1394 standard, the device functions as an IEEE 1394 network.

Here, it is assumed that nodes 84 to 86 are connected to the network as shown in FIG. 2B. That is, this is a case where 64 nodes or more are connected. In such a case, the physical ID is saturated at 62, and the physical layer 13 notifies the bus manager function unit 14 that the construction in the network has failed.
Attempt to rebuild the network bus. The network control method in such a case will be described below.

First, the information indicating that the construction of the network bus has failed directly from the bus manager function unit 14 or the physical layer 13 is acquired by the node number excess detection circuit 5 of the node designating unit 3, and the node number excess detection is performed. The circuit 5 recognizes the necessity of disconnecting the node (process 1).

Thereafter, the node specifying unit 3 determines that the physical I
A node where D is 0 (a node with a physical ID of 0 is always located at the end of the network in IEEE1394) or a node where a node with a physical ID of 0 is connected to port 1, that is, the parent node of the node to be disconnected In the case of, the disconnection instruction control unit 4 is notified that the node is a node to be disconnected or that the node to be disconnected is connected (process 2).

Then, the disconnection instruction control unit 4 receiving the notification
Instructs the port disconnection unit 2 to disconnect (process 3).

Upon receiving the instruction, the port disconnection unit 2 stops the connection signal output from the port 1 using the connection signal disconnection circuit 9, that is, detects the bias voltage itself indicating whether or not the connection state is established. By stopping, it is electrically disconnected from the network. When power is supplied to the node to be disconnected, the power supply to the physical layer 13 of the node is stopped using the power supply stop circuit 12 to stop the operation of the physical layer 13 to be disconnected. Electrically disconnect from the network. At this time, the LED as the display unit 10 indicates that the port 1 of the node to be disconnected or the port 1 to which the node to be disconnected is connected (Process 4).

When the disconnection of the node from the network is completed, the construction of the network bus is started again (process 5).

If there are still 64 or more nodes connected to the network in the processing of the above-mentioned processing 5, the processing operations from the above-mentioned processing 1 to processing 5 are repeated (step 6).

As a result, as shown in FIG. 2, a network A restricted to 63 nodes and a network B disconnected from 64 nodes or more can be constructed.

Therefore, according to the present embodiment, the IE
In the EE1394 network, even if a user erroneously connects 64 or more nodes exceeding the maximum number of 63 connected nodes, the node index excess detection circuit 5, disconnection instruction control unit 4, and port disconnection unit of the node designation unit 3 By using 2 or the like, it becomes possible to perform remote control for disconnecting the node from the network so that the maximum number of connectable nodes becomes 63 at the request of the user or automatically.
Network bus reconfiguration specified by EE1394 can be performed. As a result, data transmission between the nodes can be resumed, and a normal data communication function can be performed.

In the present embodiment, a description has been given of disconnecting from the node whose physical ID is 0. However, the present invention is not limited to this. For example, the physical ID of the terminal node located at the end of the network is the most A configuration in which disconnection control is performed so as to disconnect from a large node may be adopted.

In this embodiment, for example, the user grasps the connection status of the entire network while viewing the screen of a monitor or the like as the display unit 10 and determines a node to be disconnected by an operation unit (not shown) based on the monitor information. By supplying information to the node designation unit 3 as instructed, it is also possible to adopt a configuration in which disconnection control is possible. Further, when disconnection from the network is automatically detected and instructed, and as a result, if the disconnected node is a node necessary for data transmission, a user, a user request from the operation unit, or a physical The connection state may be restored by giving an instruction to the connection restoration circuit 8 in the layer 13.

Further, in the present embodiment, the configuration in which the user specifies the node to be connected, the node specifying unit 3,
Alternatively, if the disconnection instruction control unit 4 and the port disconnection unit 2 are not included in the same node and a network bus that transmits an instruction command through a network is configured, 64 or more nodes are connected. A means for inhibiting the reconfiguration of the network bus that occurs may be provided. As a result, it is possible to immediately restart data communication without causing unnecessary rebuilding operation of the network bus.

Next, a second embodiment of the network control method will be described in detail with reference to FIG.

FIG. 3 is an explanatory diagram for explaining a second embodiment of the network control method.
2 shows a connection state in which a non-operating node in which data packets cannot be transmitted / received and power is supplied only to the physical layer 13 exists at the end of the network.

Therefore, as shown in FIG.
In the IEEE 1394 network connected by the nodes 28, the node 28 connected to the end of the network is the non-operation node C. This node 28
This node is a node that cannot transmit and receive data packets. In other words, according to the IEEE 1394 standard, power is supplied to the physical layer 13 via the transmission cable 17.
Layer 15 is the unpowered node. This node is commonly called a "repeater."

According to IEEE 1394, as described above, when a non-powered device is connected to a network as a node, at least the physical layer 13 can be supplied with power via the transmission cable 17 and operate as a repeater. . However, if the LINK layer 15 is not operating, data necessary for the user, such as video data and control commands, cannot be transmitted. Further, the repeater is the termination node 28 (non-operation node C shown in FIG. 3).
In this case, since another node is not connected, even if this node is disconnected, it is not disconnected from the network. Therefore, a network control method in such a network will be described below.

First, the non-operation node detecting circuit 6 of the node designating section 3 makes the physical layer 13 and the LINK layer 1 of its own node.
5. Acquire from one of the bus manager function units 14 information that the physical layer 13 of the node (child node) connected to the port 1 is supplied with power via the transmission cable 17 and is a terminal node, The necessity of disconnecting the node is recognized (process 1).

Thereafter, the node specifying unit 3 determines that the child node (non-operation node C shown in the figure) connected to the port 1 of its own node (node 24 in this case) is to be disconnected, An instruction is given to the disconnection instruction control unit 4 to electrically disconnect the node by stopping the power supply (process 2).

Then, the disconnection instruction control unit 4 controls the power supply stop circuit 12 of the board disconnection circuit 2 to instruct the power supply stop circuit 12 to stop supplying power to the port 1 via the transmission cable 17 (Process 3). ).

Then, the power supply stop circuit 12 receiving the instruction
Operates to stop the power supply to the non-operating node C (in this case (node 28)) from the port 1 (process 4).

In this way, by stopping the power supply to the node 28 as the non-operation node C, the node 28 can be electrically disconnected from the network.

After the disconnection of the non-operation node C, the network bus may be reconfigured in the same manner as in the above embodiment, or control may be performed so as not to execute the reconfiguration.

Therefore, according to the present embodiment, the IE
A node that does not transmit or receive any data in the EE1394 network, that is, a non-operating node, is connected to the power stop circuit 1
2 makes it possible to disconnect the inactive node from the network by stopping the power supply to the physical layer 13. This makes it possible to reduce power consumption in the network.

In this embodiment, the node to be disconnected is displayed on the display unit 10 shown in FIG. 1, for example, on a monitor or the like, and the user is asked to confirm the disconnection operation of the node. Is also good.

In this embodiment, in addition to the physical layer 13 of the non-operation node C (node 28), the non-operation node detection circuit 6, the disconnection instruction control unit 4, and the power supply stop circuit 1
2 is configured to receive power supply via the transmission cable 17, it is determined that its own node is a non-operating node, and controllable to stop power consumption of its own node. It is good.

FIG. 4 is an explanatory diagram for explaining a third embodiment of the network control method.
2 shows a connection state in which two network groups having different maximum transmission rates exist in the same network.

That is, as shown in FIG.
In a 94 network, the maximum transmission rate is 200
Nodes 30, 3 having a data transmission function of Mbps
Network group E composed of 2, 35, 36
And a network group D including nodes 31, 33, 34, and 37 having a high-speed data transmission function with a maximum transmission rate of 400 Mbps.

Normally, in IEEE 1394, it is possible to mix nodes having different maximum transmission speeds within one network, but when transmitting data packets of the same size, the transmission speed is 200 Mbps compared to 400 Mbps. In this case, the bus is occupied twice as long, and other nodes cannot transmit data during that period. Therefore, a network control method in the case of a network including two network groups D and E having different transmission rates as shown in FIG. 4 will be described below.

In the case of the above network, the bus manager function unit 14 shown in FIG. 1 is indispensable. That is, a node that has become a bus manager by constructing a network bus according to IEEE 1394 is provided with a bus manager function unit 14 for executing a function as a bus manager. The maximum transmission rate between the nodes can be recognized by using the maximum transmission rate storage means referred to as the storage means.

Therefore, first, the transmission rate detecting circuit 7 of the node designating section 3 obtains the maximum transmission rate information between the nodes in the network stored in the speed map of the bus manager function section 14 or the like, for example, as shown in FIG. It is determined whether or not the transmission speed can be divided for each network group (for example, network groups D and E) in the network shown in (1), and a node corresponding to the boundary of the network group is designated as a node to be disconnected (process 1).

Thereafter, the disconnection instruction control unit 4 of the node designated by the transmission speed detection circuit 7 of the node designation unit 3
Nodes with different maximum transmission speeds (node 30 in this case)
Board cutting unit 2 so that port 1 connected to
And control (process 2).

Then, the connection signal disconnection circuit 9 of the port disconnection unit 2 that has received the instruction interrupts the connection signal of the port 1 that has been instructed (process 3).

Accordingly, although a network is physically configured as shown in FIG. 4, it is electrically divided into a network group D and a network group E. That is, data transmission can be resumed by disconnecting the network group E having the slowest transmission rate from the network.

After the node is disconnected and the network is divided for each network group having the same maximum transmission speed, the network bus may be reconstructed in the same manner as in the above-described embodiment, or the network bus may be reconstructed. Control may be performed so that execution is not performed. In addition, when the reconfiguration is performed, the node is kept electrically disconnected, and
If it is necessary to prevent the network bus from being reconfigured, a means for executing such a function may be provided.

Therefore, according to the present embodiment, the IEEE
2 different maximum transmission rates in E1394 network
Even when there are two network groups, the node corresponding to the boundary of the groups can be disconnected such that the maximum transmission rate is divided for each network group having the same transmission rate, so that data transmission can be resumed.

In this embodiment, the network is divided for each network group having the same maximum transmission rate. However, the network is divided from one of the network groups divided by the disconnected node to the other network group. When it is desired to transmit a data packet, the connection recovery circuit 8 may be instructed to recover the connection, and the connection may be controlled to be restored.

Also, in the present embodiment, similarly to the above-described embodiment, a node to be disconnected is displayed on, for example, a monitor or the like on the display unit 10 shown in FIG. May be configured to be checked.

When a network system is configured by connecting nodes corresponding to a plurality of devices, the nodes may be connected to form a loop instead of a tree structure or a daisy chain structure. According to the present invention, even when the network is configured in this manner, the IEEE1
The network bus can be rebuilt without impairing the communication function of 394. An example of such an embodiment is shown in FIG.

FIG. 5 is an explanatory diagram for explaining a fourth embodiment of the network control method according to the present invention.
It shows a connection state in which a loop configuration exists in the EE1394 network.

That is, as shown in the figure, nodes 41 and 42 are connected to port 1 of node 40, and these nodes 41 and 42 are connected to port 1 of node 43, respectively. A node 44 located at the end of the network is connected to the port 1 of 43 to form a network. However, such a network configuration is not a connection form such as a tree structure or a daisy chain structure,
Two nodes 41 and 42 connected in parallel between 0 and 43
Exists to form a loop structure (portion F shown in the figure).

Normally, in IEEE1394, a connection form such as a tree structure or a daisy chain structure is applied. Therefore, in a network having a loop structure as shown in FIG. 5, the function of IEEE1394 itself is sufficiently exhibited. Can not. In other words, IEEE
In 1394, at the stage of constructing a network bus, a parent-child relationship is established at port 1 of each node. However, this parent-child relationship cannot be established in the loop structure, and an error is notified after a certain time has elapsed. Would.

Therefore, a network control method for reliably establishing a parent-child relationship in IEEE 1394 even in a network having such a loop structure will be described below.

First, the loop detecting circuit 1 of the node specifying unit 3
1 recognizes from the information from the bus manager function unit 14 or the physical layer 13 that a certain period of time has elapsed since the parent-child relationship of the port 1 cannot be established, and a loop structure (F shown in FIG. 4) is formed on the network. Detect presence. That is, by detecting this, the node specifying unit 3 recognizes the necessity of disconnecting the node and gives an instruction to the disconnection instruction control unit 4 of the node to be disconnected (for example, the node 42) (Process 1).

After that, the disconnection instruction control unit 4 of the node that has received the instruction performs disconnection control by giving a disconnection instruction to the port disconnection unit 2 (process 2).

Then, the connection signal disconnection circuit 9 of the port disconnection unit 2 that has received the instruction instructs the port 1 whose parent-child relationship has not been determined to stop the connection signal, and the node connected to the port 1 Is cut (process 3).

Thus, in the network shown in FIG. 5, if the node 42 is disconnected, for example, it is possible to construct a network in which a parent-child relationship is established with the nodes 40, 41, 43, and 44. In this case, the same effect can be obtained even when the node 41 is controlled to be disconnected.

If a plurality of nodes in the loop disconnect, and all ports 1 are unconnected, a connection recovery circuit 8 shown in FIG. May be controlled so as to restore only one of the connections.

Therefore, according to the present embodiment, even in the case of a network having a loop structure other than a tree structure or a daisy chain structure, control is performed such that nodes necessary for releasing the loop structure from the network are disconnected. Therefore, the network bus can be reconfigured without impairing the communication function in IEEE 1394, and a parent-child relationship based on IEEE 1394 can be established.

In each of the embodiments according to the present invention, the connection and loop structure of 64 nodes or more, such as IEEE1
In 394, an embodiment of the present invention has been described using special conditions. However, the present invention is not limited to this, and even in a normal network configuration, control may be performed to disconnect a node specified by a user. good. Particularly, when an IEEE 1394 network (PC network) centered on a personal computer and an IEEE 1394 network (AV network) centered on AV equipment are connected by a home network, an AV network and a PC are connected.
If there are no packets to be transmitted to and from the system network, the communication processing capability of the entire network deteriorates. Therefore, in such a case, it is possible for the user to maintain the communication capability of each other by controlling the AV network and the PC network so as to divide the network, and the communication capability is deteriorated due to the network configuration. Can be prevented.

In the above-described embodiment, the connection signal is electrically cut off as a method of disconnecting the port.
However, the present invention is not limited to this, and the connection signal may be logically disconnected by electrically connecting and ignoring the detection of the connection signal. As an example of logically disconnecting the control signal, there is a logic that a predetermined bit string is transmitted / received at regular intervals by radio or the like, and only when the transmission / reception cannot be performed, the connection signal is ignored assuming that the connection is not established. Cutting method. By doing so, it is possible to obtain the effect that there is no need to electrically disconnect.

[0084]

As described above, according to the present invention,
By enabling a node connected to the IEEE 1394 bus to be remotely controlled so as to be disconnected from a network by a user's request or automatically, data transmission between the nodes can be resumed, and deterioration of the data processing capability of the entire network can be prevented. The effect that power consumption can be suppressed is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a network control device configured by incorporating a network control method of the present invention.

FIG. 2 is a diagram for explaining the first embodiment, and is a network configuration diagram in a case where the network exceeds the maximum number of connectable nodes.

FIG. 3 is a diagram for explaining the second embodiment, showing a network configuration in the case where a non-operation node exists at the end of the network;

FIG. 4 is a diagram for explaining a third embodiment, and is a network configuration diagram in a case where two network groups having different transmission rates exist on a network.

FIG. 5 is a diagram for explaining a fourth embodiment, and is a network configuration diagram in a case where a loop structure exists on a network.

[Explanation of symbols]

1 port, 2 port disconnection section, 3 node designation section, 4
... disconnection instruction control unit, 5: excess node number detection circuit, 6: inactive node detection circuit, 7: transmission speed detection circuit, 8: disconnection recovery circuit, 9 ... connection signal disconnection circuit, 10: display unit, 11
... Loop detection circuit, 12 ... Power supply stop circuit, 13 ... Physical layer, 14 ... Bus manager function unit, 15 ... LINK
Layer, 16: transaction layer, 17: transmission cable,
20-86 ... nodes.

Claims (10)

[Claims] 1. A plurality of devices are provided for each device of a network configured by being connected with a predetermined topology via a transmission system, and communicate with the plurality of devices connected to the transmission system. A communication unit provided to obtain information necessary for communication, a disconnection unit for electrically or logically disconnecting a connection state between the transmission system, and information obtained by the communication unit, or based on a user request, A device specifying unit that specifies a device to be disconnected from the network; and a disconnection instruction control unit that can disconnect the specified device from the network by controlling the disconnecting unit of the device specified by the device specifying unit. A network control device, comprising: 2. The device specifying means includes an excess device number detecting device for detecting that the number of devices connectable to the network has been exceeded, and the device disconnecting from the network based on a detection result by the excess device number detecting device. The network control device according to claim 1, wherein the network control device specifies: 3. The non-operating device detecting unit connected to the end of the network and detecting a non-operating device that cannot perform the function of the communication unit, wherein the detection result by the non-operation detecting unit is provided. 2. The network control device according to claim 1, wherein a device determined as a non-operating device is designated as a device to be disconnected from the network. 4. The device designating means includes a transmission rate detecting circuit for detecting a device having a communication means having a low data transmission rate in the network, and based on a result detected by the transmission rate detecting circuit, specifies the corresponding device. 2. The device according to claim 1, wherein the device is designated as a device to be disconnected from the network.
2. The network control device according to item 1. 5. The network control device according to claim 1, further comprising connection recovery means for recovering a connection state with said communication means disconnected by said disconnection means. 6. The disconnection means includes a connection signal disconnection means, and the connection signal disconnection means electrically disconnects an output of a connection signal indicating a connection state between the communication means and the transmission system. The network control device according to claim 1, wherein the network control device is disconnected. 7. A display for notifying a user that the communication means of the device has been disconnected from the network by the disconnection instruction control means, or a display means for displaying the entire network, has been added. The network control device according to claim 1. 8. The apparatus designating means, further comprising: a loop detecting means for detecting, when the plurality of devices are connected in a loop in the network, the devices connected in a loop, wherein the loop detecting means comprises: 2. The network control device according to claim 1, wherein any one of the devices forming a loop is designated as a device to be disconnected from the network based on the detection result of (1). 9. The disconnecting means includes a power stopping means,
2. The network connection device according to claim 1, wherein the power supply stop unit stops the supply of power to the communication unit of a device connected to a terminal of the network and receiving power supply. 10. A plurality of devices are provided for each device of a network configured by connecting with a predetermined topology via a transmission system, and perform communication between the plurality of devices connected to the transmission system and A disconnection process for electrically or logically disconnecting a connection state between the communication unit and the transmission system provided for obtaining information necessary for communication; and A device designation process for designating a device to be disconnected from the network; and a disconnection instruction control process capable of disconnecting the designated device from the network by controlling the disconnection process of the device designated by the device designation process. A network control method, comprising: