JP2002238155A - Device, system, and method for controlling interval of starting of apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the intervals of starting of apparatuses to a specified interval, even when a simultaneous apparatus starting request is made. SOLUTION: A starting interval controller 10 is provided with an application message transmitting part 14 for applying apparatus starting authority via a network, an approval message receiving part 15 for giving apparatus starting permission, on the basis of the starting authority handed over via the network, and an approval message transmitting part 17 for handing the starting authority to an applicant, who applies for a starting authorization via the network, after the completion of starting of the apparatus are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boot interval management device, a boot interval management system, and a boot interval management method for managing the boot intervals of devices in order to avoid inrush current from being superimposed.

[0002]

2. Description of the Related Art In a monitoring system that collects information on equipment such as a plant or a building and collectively manages the information, a controller that controls the equipment and collects data, controls the controller, and monitors data collected by the controller. Monitoring devices are connected to the network, and these are communicating with each other as nodes of the network. Normal,
A plurality of controllers are provided for each facility. For example, in a building monitoring system, a plurality of controllers are provided for each facility such as a lighting facility, an air conditioning facility, and a security facility.

[0003] In such a monitoring system, when starting up the equipment controlled by each controller, in order to prevent the inrush current from being superimposed when the power is turned on, the startup interval for managing the startup interval of the equipment belonging to the same power supply system is controlled. It is necessary to set up a management system. In the conventional boot interval management system, for example, the monitoring device has a function as a boot interval management device that manages the boot interval of the equipment, and each controller sends a boot application message to the monitoring device via the network when the equipment is booted. After transmitting and receiving the activation approval message from the monitoring device, the equipment has been activated.

[0004]

However, the conventional boot interval management system has difficulty in efficiently processing a simultaneous boot request of devices at the time of power recovery after a power failure or a time schedule set at the same time. When a large number of activation request messages for activating a device are transmitted, there is a problem that the activation interval of the device cannot be managed. This is based on the Carrier Sense Multiple Access (CSMA) system widely used for network access control and the CSMA / CD (C
arrier Sense Multiple Access with Collision Detect
In the (ion) method, when the load is concentrated in a short time, even if the message is not lost, the processing cannot be completed within the set timeout time due to the increase in the processing load, and a timeout error frequently occurs, and the communication performance is significantly reduced. That's why. The present invention provides a boot interval management device, a boot interval management system, and a boot interval management method capable of managing a boot interval of a device at a predetermined interval even when a simultaneous boot request of the devices occurs. With the goal.

[0005]

In order to solve the above-mentioned problems, a boot interval management device according to the present invention is a boot interval management device that is connected to a device and a network and controls the boot of the device. Means for applying for the activation authority of the device via the network, means for activating the device based on the activation authority transferred via the network, and means for applying for the activation authority via the network after the completion of the device activation. Means for transferring the activation authority. With such a configuration, the activation interval management device of the present invention can prevent simultaneous activation of devices and manage the activation interval between devices at a predetermined interval.

In this case, one configuration example of the means for applying for the activation authority is configured to apply for the activation authority in a predetermined application period whose order is determined in advance. With such a configuration, the activation interval management device, for example, by setting the order of the application period to the order of the network addresses,
It is possible to prevent simultaneous application of the activation authority of the device and suppress concentration of load on the network in a short time. Further, one configuration example of the activation interval management device is as follows.
It has means for monitoring the network and granting itself the activation right if a response corresponding to the application for the activation right is not made after a predetermined period has elapsed. With such a configuration, the activation interval management device of the present invention can autonomously acquire the activation authority without the activation authority in advance. Also,
The boot interval management system of the present invention is characterized by comprising a network and a plurality of the boot interval management devices described above connected to the network.

[0007] Further, according to the boot interval management method of the present invention, a device activation right is applied via a network, the device is activated based on the activation right obtained by the application, and after the device activation is completed, the device is activated via the network. It is characterized by transferring the activation authority to the requester who applied for the activation authority. By doing so, the activation interval management method of the present invention can prevent simultaneous activation of devices and manage the activation interval between devices at a predetermined interval. In one configuration example of the activation interval management method, the application for activation authority is limited to a predetermined application period whose order is determined in advance. In this case, as a method of determining the order of application periods, for example, there is a method of shifting application periods in the order of network addresses. By doing so, simultaneous application for the activation authority of the device is prevented, and load concentration on the network in a short time is suppressed. Further, one configuration example of the activation interval management method monitors a network, and when the response corresponding to the application for the activation authority is not made after a predetermined period has elapsed, grants the activation authority to itself. By doing so, it is possible to autonomously acquire the activation authority without the activation authority in advance.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a boot interval management device according to the present invention. The boot interval management device 10 according to the present embodiment includes a facility controller 11, a communication controller 12, and a boot authority manager 13. The facility controller 11 is connected to the facility, and the communication controller 1
2 is connected to the network.

The equipment controller 11 is a control device that controls external equipment and collects data via an input / output interface. The facility device control unit 11 requests the activation authority management unit 13 to permit the activation of the facility device, and upon receiving the activation permission from the activation authority management unit 13, activates the facility device. , Activation authority management unit 1
3 is provided. The facility device control unit 11 has a function of executing a control command transmitted from the monitoring device and transmitting collected data to the monitoring device by communicating with an external monitoring device via the communication control unit 12. Also have.

The communication control unit 12 is a communication device that accesses a network by the CSMA system and communicates with another activation interval management device or monitoring device. This communication control unit 12
Has a function of transmitting a message output from the activation authority management unit 13 to another activation interval management device, receiving a message transmitted from the other activation interval management device to the network, and inputting the received message to the activation authority management unit 13. . In this case, the message exchange between the activation interval management devices is performed by subnet broadcast that performs broadcast communication within a predetermined group.
The communication control unit 12 also has a function of transmitting a message output from the equipment control unit 11 to the monitoring device, receiving the message transmitted by the monitoring device, and inputting the message to the equipment control unit 11.

The activation authority management unit 13 exchanges messages with other activation interval management devices connected via a network, and acquires and transfers the activation authority of the equipment, thereby managing the activation interval of the equipment. And a control device for preventing simultaneous activation of the equipment managed by itself and the equipment managed by another startup interval management device. The activation authority management unit 13
In order to transmit and receive an application message for applying activation authority and an authorization message for granting activation authority, respectively, an application message transmission processing unit 14, an authorization message reception processing unit 15, an application message reception processing unit 16, and an authorization message transmission processing unit 17 Having.

As shown in FIG. 2, the application message is composed of a message type, a section, an authorized node address, and an own node address. As shown in FIG. 3, the authorization message includes a message type, a section, an authorization node address, and an application prohibition time.
The message type is an identifier for identifying the type of the message, which defines the format of the data that follows, and allows the data to be decrypted. It is also used as a clue to identify the output destination of the message received by the communication control unit 12. Here, it is used to identify a message used for managing the activation interval and a message used for control by the monitoring device.

The section is 1-byte data following the message type, and is used to identify an application message and an authorization message. In this case, section = 1 indicates an authorization message, and section = 2 indicates an application message. Authorization node address indicates the application destination of the start authority in the case of the application message,
A network address of a boot interval management device having boot authority is set. In the case of the authorization message, the activation right is indicated, and the network address of the activation interval management device to which the activation authority is assigned is set.

The own node address indicates the transmission source of the message, and the network address of the activation interval management device of the transmission source is set. During the application prohibition time,
This is used to set the application prohibition period for stopping the transmission of the application message to each activation interval management device and eliminating unnecessary communication. For this reason, this activation interval management device is provided with an application prohibition timer, and an application prohibition time is notified to each activation interval management device as a set value of the application prohibition timer by an authorization message. The application prohibition period is determined by the application prohibition timer. When the application prohibition timer is 0, it is determined that the application prohibition period is not set.

In this embodiment, in order to prevent application messages from being generated or concentrated at the time of power-on or a time schedule at the same time, the activation interval management device transmits the application message only during a predetermined transmittable period. It is configured. In this case, the period of the transmittable period is determined by the product of the transmittable period and the number of boot interval management devices connected to the network, and the order in which each boot interval management device becomes the transmittable period is in the order of the network address. Decided. For example, if the transmittable period is 0.1 second and the number of activation interval management devices is 50, the cycle is 5 seconds. Therefore, the activation interval management device constituting each node can transmit an application message every 5 seconds. It is possible. In this case, the activation interval management device can transmit the application message in ascending order of the network address.

The application message transmission processing unit 14 has a function of generating an application message and transmitting the generated application message to the network via the communication control unit 12, and a function of giving activation authority to itself. Referring to FIG. 4, application message transmission processing unit 1
Operation 4 will be described. FIG. 4 is a flowchart showing the operation of the application message transmission processing unit 14. When the application message transmission processing unit 14 starts the process in response to the activation request, the application message transmission processing unit 14 waits until the transmission period of the application message is reached (step S01).

When the transmission possible period is reached, it is determined whether or not it is an application prohibition period (step S02). If it is an application prohibition period, the process returns to step S01. If the activation request is canceled while repeating steps S01 and S02, the processing is forcibly terminated. If the period is not the application prohibition period, the application message shown in FIG.
(Step S0)
3). The application message transmission processing unit 14 includes a counter indicating the number of transmissions of the application message, and increments the counter by one each time the application message is transmitted.

Next, it is confirmed whether or not the authorization message has been received (step S04). If the authorization message has been received, the counter indicating the number of transmissions of the application message is cleared and the number of transmissions is returned to 0 (step S05). ). next,
It acquires the activation authority and checks whether it has become an authorized node (step S06). As a result of the confirmation, if it is not an authorization node, the process returns to step S01, and if it becomes an authorization node, the process ends. If the authorization message has not been received within the predetermined time in step S04, it is checked whether the number of transmissions of the application message has reached the predetermined limit (step S07). As a result of the check, if the number of times has not reached the limit number, the process returns to step S01. If the number of times has reached the limit number, the permission message transmitting means 17 is requested to transmit an authorization message with its own station as an authorization node (step S0).
8), end the process.

As described above, the application message transmission processing unit 14
Operates, the activation interval management device 1 of this embodiment
0 transmits an application message for each transmittable period excluding the application prohibition period until the local station becomes an authorized node. Also,
If the permission message cannot be received even if the number of transmissions of the application message has reached the predetermined limit, the request is made to the permission message transmitting means 17 to transmit the permission message with its own station as the permission node, and the permission node is set by itself. Therefore, even when there is no node to which the activation authority is given, the activation authority can be acquired.

The authorization message reception processing unit 15 determines whether or not the activation authority has been delegated based on the received authorization message. And a function for acquiring the authorization node address set in the application message and the application prohibition time set in the application prohibition timer. The operation of the authorization message reception processing unit 15 will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the authorization message reception processing unit 15. Authorization message reception processing unit 1
5 starts processing upon receiving the authorization message. First, the reception of the authorization message is notified to the application message transmission processing unit 14 and the application message reception processing unit 16 (step S11).

Next, the authorization node address and the application prohibition time of the authorization message are extracted, and the authorization node address and the application prohibition time stored in these data are updated (step S12). Next, the extracted authorization node address is compared with the node address of the own station, and it is confirmed whether or not the own station has been given an activation right (step S13). As a result of the check, if the authorized node address is not the node address of the own station, the process is terminated. If the extracted authorized node address is the node address of the own station, the activation permission is output to the equipment control unit 11 (step S14), and the application message transmission processing unit 14 and the application message reception processing unit 16 are notified of the activation authority. Notification of acquisition (step S1
5).

As described above, the authorization message receiving processor 15
Operates, the activation interval management device 10 can acquire the authorization node address set in the application message and the application inhibition time set in the application inhibition timer by receiving the authorization message. Also, knowing that the activation authority has been delegated, the activation permission can be given to the equipment under management.

The application message reception processing unit 16 has a function of requesting delegation of activation authority based on the received application message and a function of giving activation authority to itself. The operation of the application message reception processing unit 16 will be described with reference to FIG. FIG. 6 is a flowchart illustrating the operation of the application message reception processing unit 16. Upon receiving the application message, the application message reception processing unit 16 starts processing. First, it is determined whether or not the own station is an authorized node (step S21). If the result of the determination is that the own station is an authorized node,
The authorization node address of the application message is extracted and compared with the node address of the own station, and it is determined whether or not the application is addressed to the own station (step S22).

Here, when the authorization node address of the application message is a value indicating a specific group or a value that does not specify an address such as 0, it is considered to be addressed to the own station. Thus, even when the application source cannot recognize the authorization node address, the application message can be transmitted to the authorization node. If the result of the determination in step S22 is that the request is addressed to the own station, a request is made to the authorization message transmission processing unit 17 to transmit an authorization message with the application source of the application message as the authorization node (step S23). In this case, the self-node address of the application source extracted from the application message at the time of the request is notified to the authorization message transmission processing unit 17. If the result of the determination is not an application addressed to the own station, the process ends.

If it is determined in step S21 that the own station is not an authorized node, the own node address of the application source is extracted from the application message and compared with the node address of the own station. Is determined (step S24). If the result of determination is that the own station is the application source, the process ends. If the own station is not the application source, a predetermined time monitoring timer is set, and it is confirmed whether an authorization message is received within the time of the time monitoring timer (step S).
25). When the reception notification of the authorization message is obtained within the time of the time monitoring timer, the process ends. Note that the timed monitoring timer is longer than the transmittable period of the application message,
It is a time shorter than one cycle of the transmission available period.

When the reception notification of the authorization message is not obtained within the time of the timed monitoring timer, it is determined that there is no authorization node, the activation request is canceled (step S26), and the own station is transmitted to the authorization message transmission processing unit 17 by the authorization node. Is requested (step S27), and the process ends. In this case, the activation interval management device 10 detects that there is no node to which the authorization authority is given by using the application message transmitted by the other activation interval management devices, and transmits the authorization message addressed to itself in place of the application message. Send. Therefore, it is not necessary to wait for the retry-over of the application message, so that the authorized node can be established early.

The authorization message transmission processing unit 17 has a function of generating an authorization message and transmitting it to the network via the communication control unit 12. The operation of the authorization message transmission processing unit 17 will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the authorization message transmission processing unit 17. The authorization message transmission processing unit 17 starts processing in response to an authorization message transmission request. First, it is confirmed whether or not the request source of the activation authority is the own station (step S31).
If the requester of the boot authority is another boot interval management device,
It is confirmed whether or not the start-up completion has been notified from the equipment controller 11 (step S32). When the completion of the activation has been notified, the authorization message shown in FIG. 2 is generated, and the own node address of the application source is set in the authorization node address portion.
A predetermined temporary application prohibition time is set in the application prohibition time section and transmitted (step S33). Thus, the activation authority can be transferred to another activation interval management device.

If the completion of the activation has not been notified, the node address of the own station is set in the authorized node address portion, and the application prohibition time of the own station is set in the application prohibition time portion and transmitted (step S34). . As a result, it is possible to prevent unnecessary activation message transmission by other activation interval management devices. In step S31, if the request source of the activation authority is the own station, the process waits until the transmission period of the application message is reached (step S35), and then the process of step S34 is performed. As a result, it is possible to give the activation authority to itself and make it an authorized node.

Next, a description will be given of a method of realizing the activation interval management device with reference to FIG. FIG. 8 is a block diagram illustrating an example of a hardware configuration of the activation interval management device. The hardware of the boot interval management device is a CPU
1, a controller 20 including a RAM 22, a ROM 23, an input / output interface 24, a communication interface 25, and a bus 26 connecting these. Here, the CPU 21 is constituted by an arithmetic device such as a microcomputer, and the RAM 22 and the ROM 23 are constituted by semiconductor memories. The input / output interface 24 is configured by a parallel interface or a serial interface, and the communication interface 25 is configured by a communication control circuit connectable to a local area network (LAN).

In such a configuration, the equipment controller 11 is realized by the CPU 21 executing a program for realizing the function of the equipment controller 11 stored in the ROM 23. In this case, signals such as a start request, start permission, and start completion are transmitted via the input / output interface 24 connected to the equipment. The communication control unit 12 is realized by the CPU 21 executing a program for realizing the function of the communication control unit 12 stored in the ROM 23. In this case, communication data such as an application message and an authorization message is transmitted and received via the communication interface 25 connected to the network. The boot authority management unit 13 is a program that realizes the function of the boot authority management unit 13 stored in the ROM 23.
This is realized by being executed by U21. Note that data such as an application message, an authorization message, activation authority, the presence or absence of an activation request, and each timer are stored in the RAM 22, and the CPU 21 refers to and rewrites the data.

Next, a boot interval management system according to the present invention will be described using a monitoring system using the boot interval management device as an example. FIG. 9 is a block diagram showing a configuration example of a monitoring system using the start interval management device according to the present invention. In FIG. 1, a monitoring device 2 and n activation interval management devices 10 are connected to a network 1, and equipment 3 is connected to each activation interval management device 10. In this case, the activation interval management system includes a network 1 and n activation interval management devices 10. Note that n is an integer of 2 or more and the maximum value is network 1
Is the number obtained by subtracting the number of nodes used by devices other than the startup interval management device such as the monitoring device 2 from the number of nodes that can be connected to.

The monitoring device 2 and each activation interval management device 10
Each has a unique network address and has a function of communicating with each other via the network 1. Here, the network addresses of the activation interval management devices are grouped according to the power supply system of the equipment, and the network addresses of the same group are set in the activation interval management devices of the equipment belonging to the same power supply system. Also,
The network address of each activation interval management device in the group is set to be a continuous address number in the group. Here, description will be made assuming that all the equipments belong to the same power supply system.

Next, the operation of the boot interval management system in this monitoring system will be described with reference to FIG. Figure 1
0 is a timing chart for explaining the operation of the boot interval management system according to the present invention. In the figure,
(A) shows the operation of the startup interval management device of the node 1 in the network, and (b) shows the operation of the startup interval management device of the node 2. Further, the reference numerals N0 to N2 attached to the respective messages in FIG. 10 indicate the nodes to be set in the authorized node addresses.

First, in a state where there is no authorized node having the activation authority, the activation interval management device of the node 1 (hereinafter referred to as node 1)
), The node 1 receives the authorization message or transmits an application message in which the authorization node address is set to 0 every transmission possible period until a predetermined number of times is reached. On the other hand, when the activation interval management device of the node 2 (hereinafter, referred to as the node 2) receives the application message transmitted by the node 1, the activation interval management device activates a time monitoring timer to perform time monitoring. If the authorization message is not received within the timed monitoring period, the node 2 transmits an authorization message in which the network address of the node 2 is set to the authorization node address in the next transmittable period, and sets itself as the authorization node.

The node 1 receives the authorization message transmitted from the node 2 and recognizes that the node 2 is an authorization node having the activation authority, and makes an application message in which the authorization node address is set to the node 2 during the next transmittable period. Send
When receiving the application message transmitted by the node 1, the node 2 transmits an authorization message in which the network address of the node 1 is set to the authorized node address. When receiving the authorization message, the node 1 identifies that the activation authority has been acquired, and outputs an activation permission to the equipment under management.

When a start request is input to the node 2 when the node 1 has the start authority, the node 2 transmits an application message in which the authorized node address is set to the node 1 during the next transmittable period. Upon receiving this application message, the node 1 checks whether the equipment has been started up. In this case, since the activation has not been completed, the node 1 transmits an authorization message in which the network address of the node 1 is set to the authorized node address. When receiving the authorization message, the node 2 transmits an application message with the node 1 as the authorized node address again in the next transmittable period.

When receiving the request message, the node 1 checks whether the equipment has been started up. In this case, since the activation has been completed, the node 1 transmits an authorization message in which the network address of the node 2 is set to the authorization node address, and delegates the activation authority to the node 2. When receiving the authorization message, the node 2 identifies that the activation authority has been acquired, and outputs an activation permission to the equipment under management.

As described above, according to the start interval management system, the start interval can be managed so that the equipment is not started simultaneously. Also, since the authorization node is determined by transmitting the application message by one activation interval management device, it is not necessary to determine an authorization node having activation authority in advance, and it is not necessary to adjust the activation interval between the equipments. Equipment can be easily increased or decreased. further,
Even if a startup interval management device that cannot exchange messages due to a failure or the like occurs, application and delegation of an authorization node are performed between normal startup interval management devices, which may affect the startup of equipment managed by other startup interval management devices. do not do.

In this embodiment, an example has been described in which the startup intervals of equipment such as plants and buildings are managed. However, the present invention is not limited to the management of the startup intervals of equipment.
It goes without saying that the present invention can be applied to general equipment. Also, the example has been described in which the startup interval management device and the equipment are connected one-to-one, but various modifications are possible, such as connecting a controller to which a plurality of equipments are connected and the startup interval management device. . In addition, although it has been described that all the equipments belong to the same power supply system, it is possible to cope with a case where the equipments are divided into a plurality of power supply systems. In this case, by grouping the network addresses of the startup interval management devices for each power supply system, the startup intervals of the equipment can be managed independently for each power supply system.

[0040]

As described above, according to the present invention,
The devices that belong to the same power system are started only by devices connected to the authorized node that has the right to start, and the right to start is transferred after the start of the devices is completed. Can be managed at predetermined intervals. In addition, since the application for activation authority is limited to a predetermined application period in a predetermined order, load concentration on the network in a short time due to a simultaneous activation request of devices is suppressed,
The communication load on the network can be reduced. For this reason, even if the CSMA method is used for network access control, the activation interval between devices can be managed at a predetermined interval.

Further, when the network is monitored and a response corresponding to the application for the activation right is not made even after a predetermined period has elapsed, the activation authority is given to itself, so that the activation authority can be acquired autonomously. . For this reason, it is possible to manage the start interval between the devices at a predetermined interval regardless of the increase or decrease of the devices. In addition, even if any abnormality occurs in any node, application and delegation of activation authority are performed between the remaining nodes, so that the devices can be started without any problem except for the device of the node in which the abnormality has occurred.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a boot interval management device according to the present invention.

FIG. 2 is an explanatory diagram showing a configuration of an application message.

FIG. 3 is an explanatory diagram showing a configuration of an authorization message.

FIG. 4 is a flowchart illustrating an operation of an application message transmission processing unit.

FIG. 5 is a flowchart illustrating an operation of an authorization message reception processing unit.

FIG. 6 is a flowchart showing the operation of an application message reception processing unit.

FIG. 7 is a flowchart illustrating an operation of an authorization message transmission processing unit.

FIG. 8 is a block diagram illustrating an example of a hardware configuration of a boot interval management device.

FIG. 9 is a block diagram showing a configuration example of a monitoring system using the startup interval management device according to the present invention.

FIG. 10 is a timing chart illustrating the operation of the boot interval management system according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Network, 2 ... Monitoring device, 3 ... Facility equipment, 10
... Boot interval management device, 11 Facility equipment control unit, 12 Communication control unit, 13 Boot authority management unit, 14 Application message transmission processing unit, 15 Authorization message reception processing unit, 16
... application message reception processing unit, 17 ... authorization message transmission processing unit, 20 ... controller, 21 ... CPU, 22 ...
RAM, 23 ROM, 24 input / output interface,
25: communication interface, 26: bus.

Claims (7)

[Claims] 1. An activation interval management device connected to a device and a network for controlling activation of the device, a unit for applying for an activation right of the device via the network, and a transfer via the network. Means for activating the device based on the determined activation authority, and means for transferring the activation authority to an application source that has applied for the activation authority via the network after the activation of the device is completed. Start interval management device. 2. The boot interval management device according to claim 1, wherein said means for applying for said boot authority is applied for said boot authority during a predetermined application period in a predetermined order. apparatus. 3. The boot interval management device according to claim 1, wherein the network is monitored, and if a response corresponding to the application for boot authority is not made even after a lapse of a predetermined period, the boot authority is assigned to itself. An activation interval management device, characterized in that the activation interval management device has means for providing the activation interval. 4. A boot interval management system comprising: a network; and a plurality of boot interval management devices according to claim 1 connected to the network. 5. Applying for the activation authority of the device via a network, activating the device based on the activation authority obtained by the application, and applying for the activation authority via the network after the completion of the activation of the device. A boot interval management method, wherein the boot authority is transferred to a requesting application source. 6. The boot interval management method according to claim 5, wherein the application for the boot authority is limited to a predetermined application period whose order is determined in advance. 7. The boot interval management method according to claim 5, wherein the network is monitored, and when a response corresponding to the application for boot authority is not made after a predetermined period has elapsed, the boot authority is assigned to itself. A start interval management method, characterized in that the start interval is provided.