JP2000251187A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system capable of quickly and easily changing the communicating party of a slave unit without the need of changing the communicating party in the slave unit at a slave unit installed place at the time of fault of a master unit. SOLUTION: For this communication system, a present ID, a slave ID and a spare ID are held in a master unit 1, a present ID, a master ID and a spare ID are held in the slave unit 2 and a present ID, a slave ID and a spare ID are held in a spare master unit 4. Then, at the time of the fault of the master unit 1, the slave unit 2 transmits a sensor change report c to the spare master unit which corresponds to the spare ID held by the slave unit 2. When the spare master unit 4 which receives the sensor change report c transmits a confirmation response d including the spare ID held by the master unit 4 to the slave unit 2, the slave unit 2 changes the master ID and the spare ID and changes the communicating party.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system in which a plurality of slave units are connected to a master unit, and more particularly to a communication system capable of quickly and easily recovering from a failure of a master unit.

[0002]

2. Description of the Related Art Communication systems in which a plurality of slave units are connected to a master unit by wire or wirelessly and data from the slave units are transmitted to the master unit are now widely known. In particular, a communication system in which a sensor is connected to a slave unit, data detected by the sensor is transmitted to the master unit, and the master unit integrally manages the data is known.

An example of a conventional communication system will be described with reference to FIG. FIG. 5 is a configuration block diagram of a conventional communication system. As shown in FIG. 5, the conventional communication system includes a master unit 1 'and a slave unit 2' having a sensor 3. A plurality of slave units 2 'may be connected to one master unit 1', and a large-scale communication system including a plurality of master units 1 'is also conceivable. However, FIG. 5 shows a configuration example of one master unit 1 'and one slave unit 2' for simplicity of explanation.

[0004] Hereinafter, each part of the conventional communication system will be described in detail. The parent device 1 'receives data transmitted from the child device 2' and manages the data or performs processing based on the data. In addition, the parent device 1 'has its own identifier (child ID) and the identifier (child ID) of the child device 2' to be connected set as initial parameters, and holds these IDs. In particular, the child ID is an identifier of the child device of the communication partner. Further, the master unit 1 'returns an acknowledgment b' to the sensor change notification a from the slave unit 2 ', and notifies the slave unit 2' that the sensor change notification a has been received.

[0005] The slave unit 2 'is provided with a sensor 3, and when a change item is input from the sensor 3, notifies the master unit 1' of the content (data) of the sensor change item as a sensor change notification a. Then, upon receiving the confirmation response b 'from the base unit 1', it recognizes that the transmitted sensor change notification a has been received by the base unit 1 ', and specifies the base unit 1' as a subsequent communication partner. . The slave 2 'has its own identifier (own ID) and the identifier (parent ID) of the parent device 1' to be connected as initial parameters, and holds these IDs. In particular, the parent ID is an identifier of the parent device of the communication partner. Normally, since the slave unit 2 ′ is driven by a battery, the power is turned off. When a change item is input from the sensor 3, the slave unit 2 ′ is turned on by the control from the sensor 3. Thus, communication with the master unit 1 'becomes possible.

[0006] The sensor 3 is, for example, a sensor such as a temperature sensor or a pressure sensor, and items to be detected (temperature, pressure, etc.).
If there is a change in, the sensor change items are output. Also, the sensor 3 outputs a power-on control signal to the slave unit 2 ′ when outputting the sensor change items, and outputs the sensor change items when the slave unit 2 ′ is turned on. Has become.

Next, the operation of the conventional communication system will be described. First, it is assumed that the parent device 1 'has its own I
D = 1 and child ID = 2 are set, and the child device 2 'has its own ID.
= 2 and parent ID = 1 are set as initial parameters. In addition, the slave unit 2 'is normally in a power-off state. When there is a change in the detection items of the sensor 3, the sensor 3 turns on the power of the slave unit 2 'and outputs the sensor change items. The slave unit 2 'having received the sensor change item transmits the sensor change notification a as transmission data to the master unit 1' indicated by the parent ID of the internal setting, and the confirmation response b 'from the master unit 1'. Wait for a reply.

Next, upon receiving the sensor change notification a, the master unit 1 'fetches the data and sets the child I of the internal setting.
An acknowledgment b 'for notifying the data reception to the slave unit 2' indicated by D is transmitted. Upon receiving the confirmation response b ', the child device 2' specifies the parent device 1 'as a communication partner, and transmits the next sensor change notification to the parent device 1'.

In the above-mentioned conventional communication system, a description will be given of a recovery process when a parent machine fails. In the conventional communication system, when the master unit 1 'fails, the master unit 1' is replaced with another master unit. In this case, it is necessary to change the master unit ID held by the slave unit 2 '.
It must be done manually. This is because the child device 2 'is normally in the power-off state, so that the setting of the parent ID cannot be changed by communication with another child device turning on the power of the child device 2'.

[0010] As a conventional technique of installing a sensor in a slave unit and communicating with the master unit wirelessly, a conventional technology is disclosed in 1993 (1993).
Japanese Patent Application No. 5-128387 published on May 25, "Wireless Analog Sensor" (applicant: Hochiki Co., Ltd., inventor: Hiroshi Shima). According to this conventional technique, a detection signal such as a temperature is wirelessly transmitted to a parent device remote from the child device, and is transmitted from the child device to the parent device only when the detected temperature is equal to or higher than a preset value. That is, necessary data can be transmitted without impairing the battery life.

[0011]

However, in the above-mentioned conventional communication system, it is necessary to manually change the parent ID held by the child device, so that when the child device is installed in a remote place, However, there is a problem that it takes a lot of time and cost.

The present invention has been made in view of the above circumstances, and when replacing a master unit in the event of a failure of the master unit, it is possible to change the parent ID of the slave unit without going to the installation location of the slave unit. An object of the present invention is to provide a communication system that can be easily performed.

[0013]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems of the prior art has a feature that allows a slave unit to hold an identifier of a spare master unit as an alternative unit when a master unit fails, and The slave unit notifies the spare master unit of the identifier of the held spare master unit to the result of the sensor detection, and can quickly and easily switch the communication of the slave unit when the master unit fails.

The present invention for solving the problems of the above conventional example is a communication system according to the present invention, wherein
In the response of the receipt confirmation, include the identifier of the next spare master unit,
The slave unit that has received the response to the reception confirmation updates the identifier of the spare parent unit set in the internal configuration with the identifier of the next spare parent unit included in the response to the reception confirmation. Switching can be performed quickly and easily, and switching to the next spare master unit is possible even when the spare master unit fails.

[0015]

Embodiments of the present invention will be described with reference to the drawings. Note that the function realizing means described below may be any circuit or device as long as the function can be realized, and some or all of the functions may be realized by software. is there. Further, the function realizing means may be realized by a plurality of circuits, or the plurality of function realizing means may be realized by a single circuit.

A communication system according to an embodiment of the present invention comprises a sensor, a slave unit for notifying a detection result of the sensor, and a master unit for receiving a notification from the slave unit and responding to the slave unit with a reception confirmation. In the communication system, the ID of the spare master unit serving as a substitute unit when the master unit fails is held in both the master unit and the slave unit, and when the master unit fails, the ID of the spare master unit held by the slave unit is reserved. It has means for notifying the master unit of the detection result of the sensor. Thus, when the master unit is replaced when the master unit fails, the communication partner of the corresponding slave unit can be easily changed without visiting the slave unit installation location.

Further, in the communication system according to the embodiment of the present invention, the spare master unit that has received the notification of the sensor detection result from the slave unit transmits the notification of the reception confirmation including the ID of the next spare master unit. Since the slave unit updates the ID of the spare master unit set in the internal unit with the ID of the spare master unit included in the notification, even if the spare master unit which is a substitute for the master unit further fails, the next Can be replaced quickly and easily with the next failure.

That is, in the communication system according to the embodiment of the present invention, the identifier (spare ID) of the spare master unit (alternate machine when the master unit has failed) is set in advance in the slave unit, and When the slave receives an acknowledgment including the next spare ID from the spare master at the same time (the identifier of the alternative machine when the spare master fails next), the slave sets the preset spare ID to the master. ID and the preset spare ID are changed to the next spare ID, and the change of the identifier (parent ID) of the parent device of the child device when the parent device fails is sent to the child device installation location. And can be easily realized.

A communication system according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a configuration block diagram of a communication system according to an embodiment of the present invention. Note that parts having the same configuration as in FIG. 5 are denoted by the same reference numerals and described. In addition, in order to simplify the description, a configuration including one master unit and one slave unit is shown. ing. As shown in FIG. 1, the communication system according to the embodiment of the present invention includes a master unit 1, a slave unit 2 having a sensor 3, and a spare master unit 4. A plurality of slave units 2 may be connected to one master unit 1, and a large-scale communication system including a plurality of master units 1 may be considered.

Hereinafter, each unit of the communication system according to the embodiment of the present invention will be specifically described. The master unit 1 receives data transmitted from the slave unit 2 and manages the data or performs processing based on the data. The base unit 1 also has its own identifier (own ID) and the slave unit 2 to be connected to.
Identifier (child ID) and spare master unit 4 as a substitute in case of failure
(Preliminary IDs) are set as initial parameters, and hold these IDs. In particular, the child ID is an identifier of the child device of the communication partner. Further, the base unit 1 returns an acknowledgment b to the sensor change notification a from the slave unit 2 and notifies the slave unit 2 that the sensor change notification a has been received. Note that this confirmation response b includes the spare I
D is included.

The slave unit 2 has a sensor 3 and, when a change item is input from the sensor 3, notifies the master unit 1 of the content (data) of the sensor change item as a sensor change notification a. Then, upon receiving an acknowledgment b from the base unit 1, it recognizes that the transmitted sensor change notification a has been received by the base unit 1, and identifies the base unit 1 as a subsequent communication partner. The slave unit 2 also internally stores its own identifier (own ID), the identifier of the master unit 1 (parent ID) of the connection destination, and the identifier (spare ID) of the spare master unit as an alternative unit when the master unit fails. Are set as initial parameters and hold these IDs. In particular, parent I
D is the identifier of the master unit of the communication partner. Normally, since the slave unit 2 is driven by a battery, it is in a power-off state, and when there is an input of a change item from the sensor 3, the power is turned on under the control of the sensor 3, Communication with the master unit 1 becomes possible.

The sensor 3 is, for example, a sensor such as a temperature sensor or a pressure sensor, and the items to be detected (temperature, pressure, etc.)
If there is a change, the sensor change item is output to the slave unit 2. Items detected in the present invention are not particularly limited, and may be humidity, density, speed, intensity, brightness, and the like. Also, when outputting the sensor change items, the sensor 3 outputs a power-on control signal to the slave unit 2,
When the slave unit 2 is powered on, the sensor change items are output.

Next, the operation of the communication system according to the embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 7 is an explanatory diagram showing a recovery process when a parent device fails in the communication system according to the embodiment of the present invention. In advance, master unit 1
The own ID = 1, the child ID = 2, and the spare ID = 3 are set as initial parameters, and the own device = 2 and the parent ID =
1, the spare ID = 3 is set as an initial parameter, and the spare parent device 4 has its own ID = 3, child ID = 2,
D = 4 is set as an initial parameter. Also,
Normally, the child device 2 is in a power-off state.

Then, when there is a change in the detected item at the sensor 3, the sensor 3 turns on the power of the slave unit 2 and outputs the changed item of the sensor. The slave unit 2 to which the sensor change item is input is the master unit 1 indicating the change item by the parent ID of the internal setting.
To the parent device 1
Waits for a response b from the server.

Next, the master unit 1 that has received the sensor change notification a
Transmits the acknowledgment b notifying the reception of data to the child device 2 indicated by the child ID of the internal setting, while taking in the data. This confirmation response b includes the preliminary ID.
Upon receiving the confirmation response b, the child device 2 specifies the parent device 1 as a communication partner, and also transmits the next sensor change notification to the parent device 1.

Next, a description will be given of a recovery process in the case where the parent machine 1 has failed. When the main unit 1 fails, the main unit 1 turns on the power of the spare main unit 4. Then, even when the slave unit 2 transmits the sensor change notification a to the master unit 1 in the failure state of the master unit 1, there is no reply from the master unit 1. The slave unit 2 that cannot receive the confirmation response from the master unit 1 transmits the sensor change notification c to the spare ID held as a parameter inside.

The spare master unit 4 that has received the sensor change notification c from the slave unit 2 transmits the spare ID of the spare master unit serving as the substitute unit to the slave unit 2 in the acknowledgment d. The slave unit 2 that has received the confirmation response d changes the parameter of the internal setting. Specifically, the parent ID = 3,
The spare ID is set to 4, the parent ID is updated with the spare ID, and the previous spare ID is updated with the spare ID included in the confirmation response d. Thereafter, the slave unit 2 specifies the spare master unit 4 as the master unit, and sets the spare ID =
4 is recognized.

FIG. 3 shows the processing inside the slave unit 2 in the above processing.
This will be described with reference to FIG. FIG. 3 is a flowchart showing processing in slave unit 2 at the time of master unit failure recovery. Slave unit 2
The sensor change notification a is transmitted to the master unit 1 (S1). next,
Confirmation response b from master unit 1 to sensor change notification a
Is determined (S2), and if there is a confirmation response b (Yes), the process ends. Confirmation response b
If there is no (No), the spare master unit 4 indicated by the spare ID
To the sensor change notification c (S3).

Then, the slave unit 2 sends the sensor change notification c.
It is determined whether there is an acknowledgment response d from the backup master unit 4 (S4). If there is an acknowledgment response d (Yes),
The parent ID and the spare ID are changed (S5). In particular,
The parent ID is updated with the spare ID, and the spare ID is updated with the spare ID included in the confirmation response d. If there is no acknowledgment d (in the case of No), it is determined that the switching of the base unit 1 has failed, and a base unit switching abnormality is reported (S6), and the process is terminated.

If there is no acknowledgment d in the determination process S4, the process S6 of the master unit switching abnormality report is performed. However, since the acknowledgment d includes a new spare ID, this time,
A sensor change notification may be transmitted using this spare ID to switch to the next spare master unit.

Next, a description will be given, with reference to FIG. 4, of a recovery process performed when one master unit fails in a communication system in which a plurality of master units receive and process data from a plurality of slave units.
FIG. 4 is a configuration block diagram in a case where the communication system according to the embodiment of the present invention has a plurality of master units. still,
FIG. 4 shows an example in which two master units 1a and 1b perform processing by performing load distribution. In the communication system shown in FIG. 4, master units 1a, 1b and slave units 2a, 2b, 2c, 2d
The slaves 2a and 2b belong to the management group of the master 1a, and the slaves 2c and 2d belong to the management group of the master 1b.

The spare ID is equal to the master unit 1b.
Is set, the spare ID = master 1a is set in the master 1b, the spare ID = master 1b is set in the slaves 2a, 2b, and the spare ID = master is set in the slaves 2c, 2d. 1a is set.

If the master unit 1a fails, the slave units 2a and 2b send a sensor change notification to the master unit 1b indicated by the spare ID in accordance with the above-described recovery processing. Upon receiving the change notification, it returns an acknowledgment to the slave units 2a and 2b. Thereby, the master unit 1b communicates with the slave units 2a and 2b belonging to the management group of the master unit 1a.

According to the communication system according to the embodiment of the present invention, an identifier (spare ID) of spare master device 4 is assigned to slave device 2 in advance.
Is set, and when the base unit 1 fails, the slave unit 2 transmits a sensor change notification c to the standby base unit 4 of the standby ID, and an acknowledgment including the next standby ID from the standby base unit 4 d, the handset 2 updates the parent ID with the spare ID,
Since D is updated with the next spare ID to exchange the master unit and change the setting in the slave unit 2, it is not necessary to go to the installation location of the slave unit 2 and change the setting of the slave unit 2. There is an effect that the parent ID of the child device 2 can be easily changed without requiring any manpower.

[0035]

According to the present invention, the slave unit has a communication system for notifying the result of the sensor detection to the spare master unit having the identifier of the spare master unit held when the master unit has failed. There is an effect that communication switching between the devices can be performed quickly and easily.

Further, according to the present invention, when the slave unit receives a response of acknowledgment including the identifier of the next spare master unit from the spare master unit, the identifier of the internally set spare master unit is included in the response. Since the communication system of the present invention is updated with the identifier of the spare master unit, the communication of the slave unit can be quickly and easily switched when the master unit fails, and the next spare master unit can be switched even when the spare master unit fails. There is an effect that the switching to the machine can be easily performed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a communication system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a recovery process when a parent device fails in the communication system according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a process in the slave unit 2 at the time of recovery from a master unit failure.

FIG. 4 is a configuration block diagram in a case where the communication system according to the embodiment of the present invention has a plurality of master units.

FIG. 5 is a configuration block diagram of a conventional communication system.

[Explanation of symbols]

1, 1 ': master unit, 2, 2': slave unit, 3: sensor,
4: spare master unit, a: sensor change notification, b, b ': confirmation response, c: sensor change notification, d: confirmation response

Continued on the front page (72) Inventor Shigenori Tanabe 3-14-20 Higashinakano, Nakano-ku, Tokyo International Electric Co., Ltd. F-term (reference) 2F073 AA21 AB01 BB01 BC02 CC01 CC20 DD02 GG01 GG08

Claims (4)

[Claims] 1. A communication system comprising a sensor, a slave unit notifying a detection result of the sensor, and a master unit receiving a notification from the slave unit and responding to the slave unit with a reception confirmation, The slave unit holds an identifier of a spare master unit serving as a substitute unit when the master unit fails, and the slave unit sends the identifier of the spare master unit to be held to the spare master unit when the master unit fails. A communication system, being a slave unit for notifying a detection result of the sensor. 2. The spare master unit is a spare master unit that responds to the notification of the detection result of the sensor from the slave unit, including the identifier of the next spare master unit, when responding to the reception confirmation. The slave unit is a slave unit that, upon receiving a response to the reception confirmation from the spare master unit, updates the identifier of the spare master unit in the internal setting with the identifier of the next spare master unit included in the response to the receipt confirmation. The communication system according to claim 1, wherein: 3. A sensor that outputs a detected item when there is a change in the detected item, and a slave unit that is turned on when a detected item is input from the sensor and transmits a sensor change notification based on the detected item. In a communication system having a master unit that receives the sensor change notification and transmits a confirmation response of reception confirmation to the slave unit, the master unit has, as an internal setting, an identifier of the own device, an identifier of the slave device, A master that holds an identifier of a spare master as an alternative to the master and transmits an acknowledgment including the identifier of the spare master to the sensor change notification from the slave to the slave, The slave unit holds, as an internal setting, the identifier of the own unit, the identifier of the master unit, and the identifier of the spare master unit, and in a case where an acknowledgment cannot be obtained from the master unit in response to the transmitted sensor change notification. , Identification of the spare master unit Transmitting the sensor change notification to the spare master unit and receiving an acknowledgment from the spare master unit, updates the identifier of the master unit with the identifier of the spare master unit, and transmits the spare master unit from the master unit. The communication system according to claim 1, wherein the spare master unit is a spare master unit that transmits an acknowledgment response to the slave unit upon receiving a sensor change notification from the slave unit. 4. The spare master unit is a spare master unit that transmits an acknowledgment to the sensor change notification from the slave unit to the slave unit, including an identifier of the next spare master unit as a next alternative unit. Upon receiving the acknowledgment, the slave updates the identifier of the master set therein with the identifier of the spare master, and updates the identifier of the spare master to the next spare included in the acknowledgment. 4. The slave unit, which is updated with an identifier of the master unit, switches communication from the master unit to the spare master unit, and enables switching to the next spare master unit. Communication system.