JP2003015974A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system wherein controller equipment is provided with only a client function of a communication protocol and control target equipment is only a server function thereof in inter-equipment command transmission connected to a network. SOLUTION: In the system in which the communication protocol in which a request and a response correspond to one to one is used and two or more return values return for a control command, first equipment continuously transmits a first request for transmitting a command and one or more second requests for receiving the return value to second equipment, which returns the return value by using the response corresponding to the first and second requests.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for transmitting commands between devices in an environment where a plurality of devices are network-connected. For example, it is a communication system applied to home network technology that realizes device control by transmitting a control command from a controller device to a control target device.

[0002]

2. Description of the Related Art In recent years, with the development of network technology,
Attempts have been made to interconnect a plurality of devices with a network and control one device from another device. In this system, a device serving as a controller and a device serving as a control target are connected via a network, and the target device is remotely controlled by transmitting a control command or the like from the controller device to the target device.

For example, controlling a video tape recorder from a digital set top box (STB) can be considered as an example of controlling home electric appliances by connecting them to a network. In this case, the STB and the video tape recorder are network-connected by, for example, an IEEE 1394 serial bus standard cable. Then, the STB graphically displays a control panel for remotely controlling the video tape recorder on the CRT of the television connected to the STB. When the user operates this control panel with the remote control, the control command corresponding to the operation is sent from the STB to the video tape recorder by IEEE.
Sent over an E1394 cable. The video tape recorder that has received the control command performs the operation corresponding to the command. For example, assume that a button for playing a video tape recorder is displayed on the control panel. When the user selects this play button with the remote controller, the STB sends a play command to the video tape recorder. Then, the video tape recorder that has received the reproduction command starts the reproduction of the currently inserted video tape. By such an operation, the user can remotely operate the video tape recorder from the STB.

By the way, various media and communication protocols are used for network connection. For example, I described above
When connecting with the IEEE1394 cable, IEEE1
394 standard (IEEE Standard for a
High Performance Serial
Bus, IEEE Std 1394-1995) defined in the transaction layer and link layer protocols are used. On the other hand, in the case of the Internet, each device is connected by an Ethernet (registered trademark) cable, a telephone line, or wirelessly, and a protocol such as TCP / IP, HTTP, or FTP is used. Besides, USB and RS-232
There are various network connection media and protocols. These network connection media and protocols are
It will be installed according to the function and purpose of the device.

In general, devices equipped with different network connection media or protocols cannot be network-connected. Therefore, in recent years, in order to improve the connectability of the network, an increasing number of devices are simultaneously equipped with a plurality of types of network connection media and protocols. For example, personal computers (PCs) are Ethernet, telephone line, USB, infrared wireless, IEEE13.
It is equipped with various network connection media and protocols, such as 94 at the same time. As a result, it is possible to easily connect to a home appliance equipped with IEEE 1394 and a printer equipped with USB via a network.

When a plurality of types of network connection media and protocols are installed, unification of control commands becomes a problem. Conventionally, the control command has been uniquely defined for each network connection medium and protocol. For example, in the case of a device equipped with IEEE 1394, the control command is an AV specified by the 1394 Trade Association.
C Digital Interface Comma
The nd Set specification is used. In the case of USB, a unique command system different from this is used. As described above, when the command system varies depending on the network connection medium and the protocol, each device needs to have all the command processing functions of the command system corresponding to the type of the network connection medium and the protocol installed therein. In this case, the circuit scale, the software scale, and the cost associated therewith are increased by the number of command processing functions to be installed, which is a problem especially for home electric appliances having limited calculation resources.

As a solution to this problem, it is conceivable to control the device by using a common command that does not depend on the type of network connection medium and protocol. For example, in the communication method and the communication device disclosed in Japanese Patent Laid-Open No. 10-290245, at least a part of a plurality of command data included in a plurality of types of communication methods is commonly used in each communication method. Is characterized by. By making the command data common, the command processing function can also be made common, and the circuit scale and software scale can be reduced as a whole. However, JP-A-10-290245
Although the technology of the publication describes transmission of common command data, it is not aware of efficient transmission / reception of command data using a communication protocol.

Generally, when the controller sends a control command to the control target, a plurality of return values such as confirmation of receipt of the command and a command execution result are returned from the control target to the controller. For example, consider a case where the control command has the content of “notifying the controller of any state change in the control target”. In this case, the general procedure is
First, the controller sends a state change notification registration command to the control target, and then a confirmation return value indicating completion of acceptance of the registration command is sent from the control target to the controller. Furthermore, when a state change actually occurs in the control target, a notification of the state change is sent from the control target to the controller as a return value.

A universal plug-and-play technique is a technique that takes into consideration the mechanism in which a plurality of return values are returned, such as a state change notification. Universal Plug and Play specifications are available at the Universal Plug and Play Forum (http: //www.up.
np. org /).

Universal plug and play is a method for connecting devices to each other through a network and transmitting a device control command using an HTTP communication protocol which is often used in Internet technology. The device control command to be transmitted has a uniform format based on the XML format, and the command content is to be determined for each type of device. Here, the HTTP protocol is a communication protocol in which an HTTP request and an HTTP response correspond one-to-one.

In Universal Plug and Play, the specification of the above-mentioned status change notification is defined as the Eventing specification as follows. First, in order to register a state change notification, a controller (called a subscriber in Universal Plug and Play) sends an HTTP subscribe message to a control target (called a publisher in Universal Plug and Play).
Send along with the request. That is, SUBSCRIB
HTTP request message including E method is HT
It is sent as a TP request.

Next, in order to indicate the completion of registration acceptance, the publisher receiving this HTTP request asks the subscriber to send the HTTP corresponding to this HTTP request.
Send a TTP response. The HTTP response carries a message indicating that registration has been accepted. After that, when a state change actually occurs on the publisher side, the publisher sends an HTTP request carrying a state change message to the subscriber. That is, the HTTP request message including the NOTIFY method is transmitted as the HTTP request. The subscriber who receives this HTTP request returns an HTTP response carrying a reception confirmation message to the publisher.

[0013]

In the above universal plug and play technique, the subscriber and the publisher, in other words, both the controller device and the control target device bidirectionally send and receive an HTTP request and an HTTP response. That is, the controller device and the control target device are HTTP client functions (HT
It is necessary to equip both a TP request transmission function and an HTTP response reception function and an HTTP server function (functions for receiving an HTTP request and HTTP response transmission).

Generally, in realizing a communication protocol,
The server function is more sophisticated than the client function,
Requires abundant computational resources. Therefore, when applying home appliances and mobile phones with limited computing resources to device control by network connection, installing both the server function and the client function of the communication protocol reduces the computational resources, circuit scale, and software scale. It increases and becomes a problem.

According to the present invention, in controlling a device connected to a network, the controller device has only a client function of the communication protocol and the control target device has the communication protocol in order to reduce the calculation resource, the circuit size and the software size of the device. It is an object to provide a communication system that only needs to have a server function.

[0016]

In order to achieve the above object, the present invention employs the following means. The communication system according to claim 1 is configured by a first device and a second device connected by a communication protocol in which requests and responses correspond one-to-one, and the first device sends a command to the second device. A communication system in which, when transmitted, the second device returns two or more return values to the first device, and the first device transmits a first request for transmitting a command and a return value. One for receiving
One or more second requests are continuously transmitted to the second device, and the second device returns a return value using a response corresponding to the first and second requests. .

A communication system according to a second aspect is constituted by a first device and a second device which are connected by a communication protocol in which requests and responses correspond one-to-one.
A communication system in which when the first device transmits a command to the second device, the second device returns one or more return values to the first device, and the first device is a command To the second device, the second device returns a return value in response to the first request, the first device returns the return value. When received, a new request is sent to the second device only when the content of the return value indicates the existence of the residual return value, and the second device responds to the new request. The remaining return value is returned by.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. Figure 2
FIG. 3 is a block diagram showing a configuration of a communication system according to the first embodiment of the present invention. This communication system includes a control command generating means 1, a return value processing means 2, an HTTP request transmitting means 3, and an HTTP response receiving means 4.
And a control command processing means 5, an HTTP response transmitting means 6, and an HTTP request receiving means 7.

Of these, the control command generating means 1
The return value processing unit 2, the HTTP request transmitting unit 3, and the HTTP response receiving unit 4 constitute a controller device 201 on the controlling side. Control command processing means 5, HTTP response transmission means 6, and HT
The TP request receiving means 7 constitutes the target device 202 on the controlled side. Further, the controller device and the target device are network-connected by a communication path 203.

The communication path 203 is a controller device 201.
And the target device 202 via a network for connection. As the connection medium, any medium may be used, whether wired or wireless. For example, an Ethernet cable or the like can be used. Data according to a communication protocol interpretable by the controller device 201 and the target device 202 flows through this communication path. Although any communication protocol may be used, in the first embodiment, TCP / TCP is used as the communication lower layer protocol.
H is the IP protocol as the communication upper layer protocol
Uses the TTP protocol.

The HTTP protocol is an HTTP request message describing the contents of data to be transmitted and an HTTP.
This is a protocol in which communication devices exchange P response messages with each other. The transmission of an HTTP request message is called an HTTP request, and the transmission of an HTTP response message is called an HTTP response. H
There is a one-to-one correspondence between TTP requests and HTTP responses. That is, one HTTP response is always returned as a response to one HTTP request. Communication path 2
The HTTP request and the HTTP response are transmitted in the TCP / IP packet format on 03.

The control command generating means 1 generates command data of a control command transmitted from the controller device to the target device. This can be implemented in software or hardware.

Now, the control command system used in the first embodiment will be described. The command system may be arbitrary, but in the first embodiment, AVC Digital I
A command system based on the interface Command Set specifications is used. AVC Digital
Interface Command Set is 139
It is a specification defined by the 4 Trade Association, and is originally a control command system for remote device control used in communication using an IEEE 1394 serial bus as a medium and a protocol.

The data format of the control command for instructing the device to operate is defined as an AV / C command frame. On the other hand, the data format of the return value for the control command is defined as the AV / C response frame. Then, it is specified that the AV / C command and the response frame are encapsulated in the FCP frame portion in the FCP packet used in the communication of IEEE 1394 and transmitted / received. In the first embodiment, the AV / C command frame is adopted as the data format of the control command, and the AV / C response frame is adopted as the data format of the return value, and this is sent and received by being carried on the HTTP message.

The data format of the AV / C command frame is shown in FIG. In the following, "0x" at the beginning of the numerical values in the figures and the text indicates hexadecimal notation. AV in Figure 3
Various parameters are embedded in the / C command frame. The parameters are briefly described below.
ctype is a 4-bit value and specifies the type of command. The command type includes, for example, CONTROL requesting execution of an operation and NOTIFY registering a notification of a state change of the target device.

The 5-bit subunit_type and the 3-bit subunit_ID specify the unit type and ID of the device that receives the AV / C command frame. This specifies the detailed component on which the command acts on the device. 8
In the opcode of the bit, an operation to be executed or a monitored object of state change is designated. 8-bit opera
nd is an argument determined according to opecode. These are defined according to ctype.

On the other hand, the data format of the AV / C response frame is shown in FIG. subunit_type
e, subunit_ID, opcode, opera
Since nd is the same as each parameter of the AV / C command frame, the description thereof will be omitted.

Response is a 4-bit value,
It is a value indicating the meaning of the return value. As a return value, a value indicating the presence or absence of an error such as ACCEPTED or REJECT, or CHA meaning notification of occurrence of a state change
NGED etc. are prepared. Also, INTERIM is prepared as a special value. This is because the target device that received the AV / C command frame
This is a special value used to notify the controller that the operation instructed by the command frame cannot be started immediately. Besides, INTERIM is also used as one procedure in the notification of the state change of the target device. The procedure will be described in detail below.

First, the controller which wants to know that some state change has occurred in the target device is ct
The AV / C command frame of type = NOTIFY is transmitted to the target device. The target device that has received this AV / C command frame has received a NOTIFY request, meaning that response = INTER
The AV / C response frame used as IM is transmitted to the controller device. After that, when a state change actually occurs in the target device, the target device sets AV = response to the controller.
/ C Send a response frame. In the first embodiment, the AVC Dig is set as the parameter value of each frame.
ital Interface Command Se
The value defined by t is used as it is.

The control command generating means 1 is the AV described above.
/ C Generates control command data in the command frame format. The method of generating the control command data is not particularly limited and may be generated by any method. For example, a list of control commands is displayed on the screen of the controller device, and when the user selects one of them with the remote controller, the corresponding control command data is generated. Alternatively,
Specific command data may be generated as the activation operation of the controller device. Whichever method is used, command data in which appropriate values are set for the respective parameters of the AV / C command frame shown in FIG. 3 is generated.

An example of the control command data generated by the control command generating means 1 is shown in FIG. This is control command data of ctype = NOTIFY for requesting to notify the controller that the power of the target device has been turned off when the target device is a tape recorder. When the control command data is expressed as a byte string, it becomes 0x0320B260.

The control command data generated by the control command generating means 1 is passed to the HTTP request transmitting means 3. The HTTP request transmitting means 3 sends the control command data received from the control command generating means 1 to the HTTP
It is converted into the P request message format and transmitted to the HTTP request receiving means 7 of the target device. This is the first HTTP request. Also, another HTTP request message that does not include an AV / C command frame is simultaneously transmitted to the HTTP request receiving means 7. This is the second HTTP request. Furthermore, the HTTP request transmitting means 3 is
The HTTP response receiving means 4 is notified that the TTP request has been transmitted.

FIG. 6 shows, as an example of the HTTP request message transmitted by the first HTTP request, the control command data in the AV / C command frame format shown in FIG. 3 converted into the HTTP request message format. Further, FIG. 7 shows an example of the HTTP request message transmitted by the second HTTP request.
The HTTP request message has various header information. The POST in the first row of FIGS. 6 and 7 is this H
This means executing a cgi script named commandprocessor using the entity body of the TTP request message as a parameter.
This c is named commandprocessor
gi indicates the control command processing means 5 described later.
Other headers are unnecessary for the description of the operation of the first embodiment, and therefore detailed description thereof is omitted here. The control command data is described in the entity body part of the HTTP request message. The entity body is the end part of the HTTP request message and the HTTP response message, and is distinguished from the header part by a blank line.

The HTTP request receiving means 7 is
First HTTP sent from the P request sending means 3
Receive the request and the second HTTP request.
When an HTTP request is received, the HTTP response transmitting means 6 is first notified of the reception. Furthermore, the entity body of each HTTP request message is extracted, and if significant control command data is included, it is passed to the control command processing means 5.

The control command processing means 5 interprets the content of the control command data, performs processing in accordance with the command content, generates an appropriate return value for it, and passes it to the HTTP response transmission means 6. That is, the control command processing means 5 corresponds to a so-called command interpreter. This can be realized by software or hardware, but in the first embodiment, it is realized by a cgi script. cgi is a specification for remote script activation and is defined as an Internet draft. As a result, the HTTP request receiving means 7
When the TTP request is received, the control command processing means 5 which is a cgi script is operated with the control command data included in the TTP request as a parameter.

For example, when the HTTP request receiving unit 7 receives the HTTP request message shown in FIGS. 6 and 7, the HTTP request receiving unit 7 extracts the data contained in each entity body, which is significant control command data. The control command processing means 5 is operated using 0x0320B260 as a parameter.

The control command processing means 5 is 0x0320B
When 260 is received, this is interpreted as the control command data for requesting the state change notification shown in FIG. 5, the return value shown in FIG. 8 is first generated, and it is passed to the HTTP response transmitting means 6. The return value in FIG. 8 indicates that the request for the state change notification is accepted, and response = I
It is an AV / C response frame of NTERIM. When the return value in FIG. 8 is expressed as a byte string, it is 0x0F2
It becomes 0B270. After that, when a state change actually occurs in the target device, the control command processing means 5 detects it and generates the return value shown in FIG.
It is passed to the TP response transmission means 6. In this case, when the power of the target device is turned off, the control command processing means 5 detects it and generates the return value shown in FIG. When the return value in FIG. 10 is expressed as a byte string, it becomes 0x0D20B260.

In this example, response = I
Although a return value of NTERIM is generated, if such a return value is unnecessary, an empty return value with a data length of 0 may be passed to the HTTP response transmission means 6. The HTTP response sending means 6 sends the return value received from the control command processing means 5 as an HTTP response to the HTTP request received by the HTTP request receiving means 7. At this time, the return value is converted into the HTTP response message format and then transmitted.

For example, the return value of FIG. 8 passed from the control command processing means 5 is converted into the HTTP response message shown in FIG. Further, the return value of FIG. 10 passed from the control command processing means 5 is converted into the HTTP response message shown in FIG. These HTTP response messages correspond to the above-mentioned first H
It is transmitted as an HTTP response to either the TTP request or the second HTTP request.

The HTTP response transmitted from the HTTP response transmitting means 6 is received by the HTTP response receiving means 4. The HTTP response receiving means 4 is
After confirming that the received HTTP response is an HTTP response to the HTTP request notified that the HTTP request has been issued in the past, the entity value data included in each HTTP response is extracted to return value processing means. Pass to 2.

The return value processing means 2 performs appropriate processing according to the return value returned from the target device. This may be freely set as the design of the controller device. For example, the received return value is re as shown in FIG.
If response = INTERIM, wait for the arrival of another return value that should be returned later. And
When the return value of response = CHANGED shown in FIG. 10 is returned, the user is notified that the power of the target device has been turned off. If an empty return value with a data length of 0 is returned, do nothing.

The HTTP request transmitting means 3 and H
A combination of the TTP response receiving means 4 is generally called an HTTP client function. Further, the HTTP response transmitting means 6 and the HTTP request receiving means 7 are combined to be generally called an HTTP server function.

Next, the operation of the communication system having the above-described configuration will be described using a concrete example. To explain the operation, an example of notifying the controller device when the power of the tape recorder, which is the target device, is turned off will be used. That is, it is assumed that the control command data of FIG. 5 described above is generated and the return values of FIGS. 8 and 10 are returned.

FIG. 12 is a flow chart showing the operation of the communication system according to the first embodiment. FIG. 1 is a diagram showing a sequence of an HTTP request and an HTTP response transmitted via the communication path 203 in the communication system of the first embodiment. The controller is 101,
The target device is 102. Hereinafter, FIG. 12 and FIG.
The operation will be described based on. First, in S1001, the control command generating means 1 generates control command data based on a user instruction or the like. For example, assume that the control command data of FIG. 5 is generated.

Next, in S1002, the HTTP request transmitting means 3 converts the control command data of FIG. 5 into the first H of FIG.
Converts to a TTP request message and sends an HTTP request. At the same time, the second HTTP request message of FIG. 7 is generated and the HTTP request is transmitted.
It also notifies the HTTP response receiving means 4 that the HTTP request has been transmitted. The first HTTP request transmitted here is 111 in FIG. 1, and the second HTTP request is
The TP request is 112 in FIG. The first H
The order of the TTP request and the second HTTP request may be exchanged.

The two HTTP requests transmitted in S1002 are received by the HTTP request receiving means 7 in S1003. HTTP request receiving means 7
The control data stored in the entity body is extracted from the TTP request message, and significant data is passed to the control command processing means 5. It also notifies the HTTP response transmission means 6 of the HTTP request reception.

Next, in step S1004, the control command processing means 5 analyzes the received control command data and performs processing according to the contents. Now, assuming that the processing based on the control command data of FIG. 5 is performed, the control command processing means 5 first generates the return value of FIG. 8 in order to notify that the NOTIFY command has been accepted, and the return value of FIG.
It is passed to the response transmission means 6.

Then, the process proceeds to S1005, where HTTP
The response transmission means 6 uses the return value of FIG. 8 as the HT of FIG.
It is converted to the TP response format and sent as an HTTP response. This HTTP response is 11 in FIG.
It is 3. After that, in step S1006, the HTTP response receiving unit 4 receives this HTTP response, and returns the return value of the entity body part to the return value processing unit 2
Pass to. In S1007, the return value processing means 2 that has received the return value of FIG. 8 waits for the return value of FIG.

Here, the process returns to S1004. S100
In 4, the control command processing means 5 waits until the power of the target device is turned off. Here, when the user turns off the power of the target device, the control command processing means 5 detects this, generates a return value shown in FIG. 10, and passes it to the HTTP response transmitting means 6.

In S1005, the return value is converted into the HTTP response message shown in FIG. 11 and transmitted as the HTTP response, as in the previous case. The HTTP response transmitted here is 114 in FIG.
In step S1006, the HTTP response receiving unit 4 operates as shown in FIG.
10 is extracted from the HTTP response message of and the result is passed to the return value processing means 2. Finally S1
At 007, the return value processing means 2 notifies the user that the power of the target device has been turned off, and the processing is completed. As a result, the operation of the communication system based on the control command data transmitted in S1001 is completed. To send the control command data again, S1
It restarts from 001.

By the above-described operation, the first embodiment
The communication system can send a control command by an HTTP request and send all return values by an HTTP response.

In the above description, the HTT shown in FIG.
Although only one second HTTP request for sending the P request message is sent, multiple HTTP responses can be returned by sending multiple of these, that is, two or more return values can be returned. It is also possible to easily adopt a configuration that can.

Also, a plurality of return values can be converted into one HTTP.
It is also possible to send it in response. In this case, for example, there is a method of arranging a plurality of return values continuously in the entity body part of the HTTP response message.

(Second Embodiment) A second embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 13 is a block diagram showing the configuration of the communication system according to the second embodiment of the present invention. This communication system includes a control command generating means 11, a return value processing means 12, an HTTP request transmitting means 13, and an HTTP response receiving means 14.
And a control command processing unit 15, an HTTP response transmitting unit 16, and an HTTP request receiving unit 17.

Of these, the control command generating means 11
The return value processing unit 12, the HTTP request transmitting unit 13, and the HTTP response receiving unit 14 form a controller device 301. Control command processing means 15, HTTP response transmission means 16, and HTT
The P request receiving unit 17 constitutes the controlled target device 302. Further, the controller device 301 and the target device 302 are network-connected by a communication path 303.

Of these, the control command generation means 11 and
HTTP response receiving means 14, control command processing means 15, HTTP response transmitting means 16, and HT
Since the TP request receiving means 17 and the communication path 303 have the same functions as the constituent elements having the same name in the first embodiment, the repetitive description is omitted.

The HTTP request transmission means 13 has almost the same function as that of the first embodiment, but does not transmit the second HTTP request when transmitting the first HTTP request. The second HTTP request is transmitted after receiving the transmission request from the return value processing means 12.

In the return value processing means 12, the return value passed from the HTTP response receiving means 14 is resp.
If onse = INTERIM, the HTTP request transmitting unit 13 is requested to transmit the second HTTP request. In other cases, the processing according to the return value is performed as in the first embodiment.

Next, the operation of the communication system having the above-mentioned configuration will be described using a concrete example. For the description of the operation, as in the first embodiment, an example of notifying the controller device when the power of the target tape recorder is turned off is used. That is, it is assumed that the control command generation means 11 generates the control command data of FIG. 5 and the return value of FIGS. 8 and 10 is returned.

FIG. 14 is a flowchart showing the operation of the communication system according to the second embodiment. FIG. 15 is a diagram showing a sequence of an HTTP request and an HTTP response transmitted via the communication path 303 in the communication system according to the second embodiment. The controller is 401
The target device is 402. The operation will be described below with reference to FIGS. 14 and 15. First, S2001
Then, the control command generation means 11 generates control command data based on a user instruction or the like. For example, assume that the control command data of FIG. 5 is generated.

Next, in S2002, the HTTP request transmission means 13 converts the control command data of FIG. 5 into the first HTTP request message of FIG. 6 and transmits the HTTP request. It also notifies the HTTP response receiving means 14 that the HTTP request has been transmitted. The first HTTP request transmitted here is 41 in FIG.
It is 1.

The first HTTP request transmitted in S2002 is received by the HTTP request receiving means 17 in S2003. The HTTP request receiving means 17 is
The control data stored in the entity body is extracted from the HTTP request message, and significant data is passed to the control command processing means 15. It also notifies the HTTP response transmission means 16 of the HTTP request reception.

Next, in step S2004, the control command processing means 5 analyzes the received control command data and performs processing according to the contents. Now, assuming that the processing based on the control command data of FIG. 5 is performed, the control command processing means 15 first generates the return value of FIG. 8 in order to notify that the NOTIFY command has been accepted, and this is returned to the HTT
It is passed to the P response transmission means 16.

Then, the processing shifts to S2005, where HTTP
The response transmission means 16 uses the return value of FIG. 8 as the H of FIG.
It is converted into the TTP response format and transmitted as an HTTP response of the HTTP request received by the controller. This HTTP response is 412 in FIG. After that, in step S2006, the HTTP response receiving unit 14 receives this HTTP response, extracts the return value of the entity body portion, and passes it to the return value processing unit 12.

In S2007, the return value processing means 12 that has received the return value of FIG. 8 branches the processing according to the response value of the received return value.
In this case, the return value is as shown in FIG.
Since pose = INTERIM, the process transitions to S2008.

In S2008, the return value processing means 12
In response to the transmission request from the HTTP request transmission unit 13, the HTTP request transmission unit 13 transmits the second HTTP request that does not include the control command data shown in FIG. This HTTP request is 413 in FIG. Here, the process is again S2.
Returning to 003, the transmitted HTTP request is HTTP
The P request receiving means 17 receives the P request.

In S2003, significant control command data is extracted from the entity body of the HTTP request message received by the HTTP request receiving means 17. However, in this case, since the entity body of the HTTP request message of FIG. 7 does not include data, the HTTP request receiving means 17 only notifies the HTTP response transmitting means 6 of the HTTP request reception.

Here, the process proceeds to S2004. S200
In 4, the control command processing means 15 waits until the power of the target device is turned off. Here, when the user turns off the power of the target device, the control command processing means 15 detects this, generates the return value shown in FIG. 10, and passes it to the HTTP response transmitting means 16.

In S2005, the return value of FIG. 10 is converted into the HTTP response message shown in FIG. 11, and the H value corresponding to the second HTTP request received earlier is returned.
It is transmitted as a TTP response. The HTTP response transmitted here is 414 in FIG.

In step S2006, the HTTP response receiving means 14 extracts the return value shown in FIG. 10 from the HTTP response message shown in FIG. 11 and passes it to the return value processing means 12. In S2007, the return value is now as shown in FIG.
And response = CHANGED.
Therefore, the process transitions to S2009.

Finally, in S2009, the return value processing means 1
2 notifies the user that the power of the target device has been turned off, and the processing is completed. This allows
The operation of the communication system based on the control command data transmitted in S2001 is completed. When transmitting the control command data again, the process is restarted from S2001.

By the operation described above, the second embodiment
In the communication system, the controller transmits the second HTTP request when the controller transmits the control command by the HTTP request and receives the return value of response = INTERTERM by the HTTP response. The target device can send the final return value as an HTTP response to the second HTTP request.

In the above description, the controller device sends the second HTTP request only once, but the response value response = IN included in the HTTP response to the second HTTP request.
In the case of TERIM, the steps from S2003 to S2008 can be repeated by transmitting the second HTTP request again. That is, it is possible to send a plurality of return values from the target by a plurality of HTTP responses.

When the return value processing means 12 makes a transmission request, the HTTP request transmission means 13 causes the second H
It is also possible to transmit a plurality of return values from the target by transmitting a plurality of TTP requests at the same time.

In addition, a plurality of return values are converted into one HTTP.
It is also possible to send it in response. In this case, for example, there is a method of arranging a plurality of return values continuously in the entity body part of the HTTP response message.

Although the response value of the return value is used to determine whether to send the second request, the present invention is not limited to this, and any value may be used for the determination.

(Others) In the description of the first and second embodiments, the HTTP protocol is used as the communication protocol and the AVC Dig is used as the device control command system.
ital Interface Command Se
Although the t specification is used, the present invention is not limited to this, and any command system can be applied. Further, in the description of the operation, the sequential processing procedure has been described, but the processing may be configured to be efficient by parallel processing.

[0078]

According to the communication system of the first aspect, in controlling the devices connected to the network, the controller device only needs to have the client function of the communication protocol and the control target device only needs to have the server function of the communication protocol. . Therefore, the configuration of the device can be simplified and simplified, and the calculation resource of the device, the circuit scale, and the software scale can be reduced.

According to the communication system of claim 2, in addition to the effect of the communication system of claim 1, it is possible to reduce the communication volume by transmitting the additional request only when the return value remains.

[Brief description of drawings]

FIG. 1 is a sequence diagram showing communication contents of a communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a communication system according to the first embodiment of the present invention.

FIG. 3 is a conceptual diagram of a format of control command data of a device control command system used in the first and second embodiments of the present invention.

FIG. 4 is a conceptual diagram of a return value format of a device control command system used in the first and second embodiments of the present invention.

FIG. 5 is a diagram showing an example of control command data used in the first and second embodiments of the present invention.

FIG. 6 is a diagram showing an example of an HTTP request message transmitted by a first HTTP request used in the first and second embodiments of the present invention.

FIG. 7 is a diagram showing an example of an HTTP request message transmitted by a second HTTP request used in the first and second embodiments of the present invention.

FIG. 8 is a diagram showing an example of a return value for a control command used in the first and second embodiments of the present invention.

FIG. 9 is a diagram showing an example of an HTTP response message used in the first and second embodiments of the present invention.

FIG. 10 is a diagram showing an example of a return value for a control command used in the first and second embodiments of the present invention.

FIG. 11 is a diagram showing an example of an HTTP response message used in the first and second embodiments of the present invention.

FIG. 12 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a communication system according to a second embodiment of the present invention.

FIG. 14 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 15 is a sequence diagram showing communication contents of the communication system according to the second embodiment of the present invention.

[Explanation of symbols]

1, 11 control command generating means 2,12 Return value processing means 3,13 HTTP request transmission means 4,14 HTTP response receiving means 5,15 Control command processing means 6,16 HTTP response transmission means 7,17 HTTP request receiving means 201,301 Controller equipment 202,302 Target device 203, 303 communication path

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomonori Nakamura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yoshisuke Mimura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5B089 GA21 HA16 HB05                 5K034 AA11 BB03 DD01 KK29                 5K048 AA02 BA12 CA08 DA05 DC04                       EA11 EB02 FC01 HA01 HA02

Claims (2)

[Claims] 1. A request and a response are configured by a first device and a second device connected by a communication protocol corresponding to one-to-one, and when the first device sends a command to the second device, A communication system in which two or more return values are returned from the second device to the first device, wherein the first device receives a first request for transmitting a command and a return value. One or more second requests are continuously transmitted to the second device, and the second device returns a return value using a response corresponding to the first and second requests. Communication system. 2. A request and a response are constituted by a first device and a second device connected by a communication protocol corresponding to each other one-to-one, and when the first device transmits a command to the second device, A communication system in which one or more return values are returned from the second device to the first device, wherein the first device sends a first request for sending a command to the second device. However, the second device returns a return value by a response corresponding to the first request, and when the first device receives the return value, the content of the return value indicates the existence of the residual return value. A new request is sent to the second device only when it is indicated, and the second device returns the remaining return value by the response corresponding to the new request. Communication system according to claim Rukoto.