JPH05260198A - Circuit terminal system - Google Patents

Abstract

PURPOSE:To provide the circuit terminal system for telecontrol provided with a communication means which can execute easily a one-to-n communication. CONSTITUTION:A second terminal 5 always selects a first terminal 1a to which it is desired to execute a communication by a selection actuating means 7, and executes a data communication by occupying a circuit in order to execute a communication to the terminal 1a until the circuit is opened by a finishing means 24. In the case it is necessary that the terminal 1a executes a communication to a second terminal, the terminal 1a decides whether the circuit is being used by actuation means 3 to be selected and a means 7 to be finished or not, and when the circuit is not used, a communication start is requested to the terminal 5 by a selection actuation requesting means 2, this request is detected by a selection actuation request receiving means 6 of the terminal 5, the requested terminal is selected reversely by the selection actuating means 7 and a data communication is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line terminal system for connecting a first terminal such as a gas meter and a second terminal with a line to perform telecontrol such as automatic meter reading and gas leak notification. In particular, it relates to communication means between the first terminal and the second terminal.

[0002]

2. Description of the Related Art For example, a first terminal such as a city gas meter, an LP gas meter and a water meter is connected to a center via a telephone line, and a metal cable is connected to a terminal network control device for automatic meter reading and reporting. It is connected using the line. With respect to such a line terminal system, communication means of the first terminal device will be described with reference to FIGS. 4, 5 and 6. Here, communication between the terminal network control device and the center is outside the scope of the present invention, and in order to simplify the description, the terminal network control device and the center will be described as the second terminal. FIG. 4 shows the configuration of the first terminal and the second terminal, and FIGS. 5 and 6 show an example of communication when the first terminal is a city gas meter.

First, the configurations of the first terminal and the second terminal will be described. The first terminal 12 is connected to the second terminal 19 via the line 26.
Connected with. The first terminal 12 has an activation requesting means 13 for requesting the second terminal 19 to start communication by notification.
An activated unit 14 that receives a communication start request from the second terminal 19, a data receiving unit 15 that receives various communication processing requests and the like from the second terminal, and processing results and data for the communication processing request. The data transmission means 16 for transmitting the above information to the second terminal, the terminated means 17 for accepting the termination of communication from the second terminal, and the slave control means 18 for controlling these means. The sub-control means 18
Is designed to drive the data transmitting means 16 and the data receiving means 15 only when the activated means 14 detects a request to start communication from the second terminal 19. Further, the sub-control means 18 determines whether or not the activated means 14 and the terminated means 17 are in communication with the second terminal 19, and drives the activation requesting means 13 only in a state other than in communication. To control.

The second terminal has a start request receiving means 20 for receiving a communication start request from the first terminal 12, a start means 21 for making a communication start request to the first terminal 12, and a first terminal 12. A data transmitting means 22 for transmitting various communication processing requests and the like, a data receiving means 23 for receiving processing results, data and the like from the first terminal 12, and a first terminal 12
It is composed of a terminating means 24 for terminating communication with and a main control means 25 for controlling each of these means.

An operation example of this line terminal system will be described with reference to FIGS. An example in which the city gas meter, which is the first terminal 12, reports the gas leak to the second terminal will be described with reference to FIG.

Upon detecting a gas leak, the first terminal 12 uses the activation requesting means 13 to transmit a telegram 27 in which a telephone number to be notified indicating a communication start request is set to the second terminal. When the activation request receiving means 21 detects the message 27, the second terminal 19 drives the activation means 21 and transmits an electronic message 28 indicating the start of communication to the first terminal. This telegram 28 is set with information indicating that the communication is started by the telegram 27, that is, the first activation. First terminal 1
2, the activated means 14 detects an electronic message 28 and drives the data transmitting means 16 to transmit an electronic message 29 in which notification information such as a gas leak is set. This telegram 29 is received by the data receiving means 23 of the second terminal 19. When the second terminal 19 receives the electronic message 29 and ends the communication, the second terminal 19 uses the ending unit 24 to transmit the electronic message 30 indicating the end of the communication. As a result, the first terminal 12 has the terminated means 17
The end of communication is detected by and the series of communication operations is ended.
When the second terminal 19 continues to communicate after receiving the electronic message 29, the data transmitting means 22 is used to transmit an electronic message indicating various communication processing requests, and the transmitted electronic message is transmitted to the first terminal 12 as data. The operation is such that the receiving means 15 receives the data. Communication is continued unless the second terminal 19 ends the communication by the communication terminating means 24.

Next, an example of extracting information such as a meter reading value of the terminal from the terminal network control device will be described with reference to FIG.

The second terminal uses the activation means 21 to transmit a telegram 31 indicating the start of communication. This telegram 31 is set with information indicating that it is the second activation that also serves as a reading request of the meter reading value. When the first terminal 12 detects the message 31 by the activated means 14, the data transmission means 1
6 is driven to transmit the electronic message 32 in which the meter reading value is set. The second terminal 19 receives the electronic message 32 by the data receiving means 23. When the second terminal 19 receives the electronic message 29 and ends the communication, the second terminal 19 uses the ending unit 24 to transmit the electronic message 30 indicating the end of the communication. Thereby, the first terminal 1
In Step 2, the terminated means 17 detects the end of communication and ends a series of communication operations.

Each of the electronic messages shown in FIGS. 5 and 6 has an STX code at the beginning of the electronic message and an ETX code at the end of the electronic message, and each code forming the electronic message has a 1-bit vertical parity. A bit and a block check character (BCC) for horizontal parity check are in a format following an ETX code. Then, among the respective telegrams exchanged between the second terminal and the first terminal, the telegram 27 used for the communication start request from the first terminal, the telegram 28 indicating the communication start from the second terminal, and the telegram. As can be seen from FIGS. 5 and 6, the information for identifying the terminal is not added to 31, and the first terminal and the second terminal have a communication procedure and a telegram configuration for one-to-one communication. ing. Therefore, the second terminal has a configuration including a plurality of electrical interface means for connecting the terminals in order to realize communication with the plurality of terminals.

Now, a conventional technique for branching and connecting a plurality of first terminals to a second terminal using the same line and performing one-to-n communication between the second terminal and the first terminal will be described. .. As a means for this, there is a basic mode control procedure standardized by ISO.

This basic mode control procedure is means for performing data communication by establishing a data link for confirming the other party of communication under the control of the second terminal, receiving each other, and establishing the transmission state. As a method of establishing this data link, a polling method in which the second terminal invites each first terminal to transmit data in order, and a method for transmitting data from the second terminal to an arbitrary first terminal , A second terminal calls the first terminal. Then, in these methods, since the second terminal communicates with an arbitrary terminal, the second terminal selects the arbitrary first terminal using the identification information capable of distinguishing each of the first terminals. Method has been adopted, and bidirectional data communication is realized by using both of these methods. Further, a contention method is defined as a method for the first terminal or the second terminal to contend for the right to use the line for communication. This is because the terminal side that contended for the line is the master station and the other terminal is the slave station. It is an operation.

[0012]

However, the above-mentioned conventional technique has the following two problems when the second terminal makes one-to-n communication with the plurality of first terminals. (1) In order to connect a plurality of first terminals such as a city gas meter used in a telecontrol system to a second terminal, the terminals are connected to a terminal network control device (second terminal). An electrical interface must be provided for each first terminal. This is because the second terminal cannot distinguish and communicate with the first terminal with the conventional communication procedure between the terminal network control device (second terminal) and the first terminal and the configuration of the message. (2) When the basic mode control procedure standardized by ISO is applied to the city gas meter which is the first terminal and the terminal network control device (second terminal), the polling / selection method is An invitation to send on a regular basis must be made to each first terminal. So, for example,
The power consumption for communication increases for the first terminal and the second terminal that use the battery as a power source. The microprogram for the communication procedure also becomes large. Further, in the contention method, both the first terminal and the second terminal have to perform control to contend for the right to use the line, and not only a complicated communication procedure but also the first terminal and the second terminal are the same. It must be equipped with a microprogram for communication procedures of a moderate scale.

Therefore, an object of the present invention is to provide a line terminal system provided with a communication means capable of easily performing 1-to-n communication in order to solve such a conventional problem.

[0014]

In order to achieve the above first object, the line terminal system of the present invention is a line terminal system in which a plurality of first terminals are branched and connected to the same line to communicate with a second terminal. The second terminal selects and activates one of the first terminals, occupies a line for communication with the first terminal, and requests the start of communication, and a selection and activation means. A termination means for releasing the line occupied by the terminal and terminating communication with the first terminal; a selection activation request acceptance means for accepting a communication initiation request from the first terminal; and a first terminal selected by the selection activation means. Data transmitting means, data receiving means from the first terminal selected by the selecting and activating means, and the first terminal detects whether or not selected by the selecting and activating means, and is selected by another first terminal. The other first terminal if And the selected start-up means that determines that the line has been occupied for the communication between the second terminal and the second terminal is terminated, or the communication between the second terminal and the other first terminal is terminated and the line is opened. The means to be terminated for detecting that
The second terminal uses the selective starting requesting means for requesting the second terminal to start the communication only when the line is not occupied in order to prompt the second terminal to start the communication by using the selective starting means. And data transmission means to the second terminal.

[0015]

According to the line terminal system of the present invention, the second terminal always selects the first terminal to be communicated by the selecting and activating means, and the first terminal until the line is released by the terminating means. In order to communicate with, the data transmission means and the data reception means occupy a line to perform data communication. When the first terminal needs to communicate with the second terminal, the first terminal determines whether the line is used by the selected activation means and the terminated means, and the line is used. When not activated, the selective activation requesting means requests the second terminal to start communication, and the selective activation request accepting means of the first terminal detects this request, and reverses the requesting first terminal to the second terminal. The terminal activates the data communication by selecting with the selecting and activating means.

[0016]

FIG. 1 is a block diagram showing the construction of an embodiment of the present invention.
Shown in. FIG. 1 shows an example in which a first terminal 1a, which is a city gas meter, and a first terminal 1b, which is a water meter, are branched and connected to a second terminal 5 via a line 26. As a specific example of the second terminal, there is one including a terminal network control device connecting the first terminal and a center connecting via a telephone line. Here, communication between the terminal network control device and the center is outside the scope of the present invention, and in order to simplify the description, the terminal network control device and the center will be described as the second terminal in the same manner as in the description of the prior art. .. Further, of the blocks shown in FIG. 1, the same number is given to the same block as the conventional one. 2 and 3 show a first terminal and a second terminal of the present invention.
It shows the communication operation of the terminal.

First, the configurations of the first terminal and the second terminal will be described. The first terminals 1a and 1b are connected to the second terminal 5 via the line 26. Since both the first terminals 1a and 1b have the same configuration, only the configuration of the first terminal 1a will be described. The second terminal 5 selects one of the first terminals 1a and 1b, occupies a line for communication with the first terminal, requests the start of communication, and selects the start-up means 7. Termination means 24 for releasing the right to use the line obtained by the activation means 7 and terminating communication with the first terminal, and the first terminal 1a.
Alternatively, the selection start request receiving means 6 for receiving the communication start request from 1b, and the first selection selected by the selection starting means 7.
Data transmission means 22 for transmitting various communication processing requests and the like to the terminal 1a or 1b, and data reception means 23 for receiving the processing result or data from the first terminal 1a or 1b selected by the selection activation means 7. And extended main control means 8 for controlling each of these means.

The first terminal 1a detects whether or not it has been selected by the selection starting means 7, and when the first terminal 1b is selected, the second terminal 5 communicates with the first terminal 1b. Communication is terminated between the selected starting means 3 and the second terminal 5 or the communication between the second terminal 5 and the other first terminal 1b is terminated and the line is opened. The terminated means of the first terminal for detecting that the
The terminal 1a of the second terminal 5 requests the second terminal 5 to start communication only when the line is not occupied in order to prompt the second terminal 5 to start communication by using the selective start means 7. , A data receiving means 15 for receiving various communication processing requests and the like from the second terminal 5, a data transmitting means 16 for transmitting processing results and data etc. to the second terminal 5 to the second terminal 5, and these. It is composed of an extended slave control unit 4 for controlling each unit.

An operation example of this line terminal system will be described with reference to FIGS. It should be noted that, of the electronic messages described in FIGS. 2 and 3, the same electronic messages as in the related art are described with the same names and numbers.

An example in which the city gas meter, which is the first terminal 1a, reports the gas leak to the second terminal 5 will be described with reference to FIG.

When the first terminal 1a detects a gas leak, the first start-up requesting means 2 is used to transmit a telegram 9 in which a telephone number indicating a notification destination for prompting a communication start request is set to the second terminal 5. .. Identification information (YID) indicating transmission from the first terminal 1a is set in the electronic message 9 and transmitted. When the second terminal 5 detects the message 9 by the selective activation request accepting means 6, it drives the selective activation means 7 and transmits a message 10 indicating the start of communication to the first terminal 1a. This message 10
The information for identifying the first terminal 1a that has been set in the message 9 and the information indicating that the communication is started by the message 9 is the first activation. First
The terminal 1a determines that the selected activation means 3 has selected from the message 10 and drives the data transmission means 16 to transmit the message 29 in which notification information such as gas leak is set. In this message 29, the second terminal 5 receives the data receiving means 2
Received by 3. When the second terminal 5 receives the electronic message 29 and then ends the communication, the second terminal 5 uses the ending means 24 to transmit the electronic message 30 indicating the end of the communication. As a result, the first terminal 1a detects the end of communication by the ended means 17 and ends the series of communication operations. Also, the first terminal 1b
Determines that the terminated means 17 of the first terminal 1b has terminated the communication of the first terminal 1a and opened the line.
When the second terminal 5 continues to communicate after receiving the telegram 29, the data transmitting unit 22 is used to transmit telegrams indicating various communication processing requests, and the transmitted telegram is transmitted to the first terminal 1
2 is received by the data receiving means 15. Communication is continued unless the second terminal 5 terminates the communication by the termination means 24. Thus, the first terminal 1
Although the means 17 to be terminated of a and 1b determines the end of communication,
In case the reception of the telegram 30 indicating the end of communication from the second terminal 5 cannot be received due to a line failure, the terminated means 17 is provided.
Operates to monitor whether or not a message is received within a predetermined time, and to determine that the communication has ended if no message is received within the predetermined time.

Next, an example in which the second terminal retrieves information such as the meter reading value of the first terminal 1a will be described with reference to FIG.

The second terminal 5 uses the selective activation means 7 to transmit a telegram 11 indicating the start of communication. This message 11
Indicates that information (TID) for identifying the first terminal 1a and information indicating that the second activation is also a request for reading the meter reading value are set. The first terminal 1a detects the telegram 11 by the selected activation means 3 and drives the data transmission means 16 to transmit the telegram 32 in which the meter reading value is set. The second terminal 19 receives the electronic message 32 by the data receiving means 23. When the second terminal 5 receives the electronic message 32 and then ends the communication, the second terminal 5 transmits the electronic message 33 indicating the end of the communication by using the ending unit 24. Thereby, the first terminal 1a
Ends the communication and ends the series of communication operations. Further, the first terminal 1b determines that the terminated means 17 of the first terminal 1b has finished communication with the first terminal 1a and opened the line. Second terminal 5
When the user continues to communicate after receiving the message 32, similarly to the gas leak notification, a message indicating various communication processing requests is transmitted using the data transmission means 22, and the transmitted message is transmitted to the first terminal 1a. Is received by the data receiving means 15. Communication is continued unless the second terminal 5 terminates the communication by the termination means 24. In this way, the terminated means 17 of the first terminals 1a and 1b determines the end of communication, but the message 30 indicating the end of communication from the second terminal 5 is transmitted.
In case the reception of the message is not possible due to the line failure, the terminated means 17 monitors whether or not the message is received within a predetermined time, and if the message is not received within the predetermined time, it is determined that the communication is completed. Operates to judge.

When an event that should be reported to the first terminal 1b occurs while the first terminal 1a is performing data communication with the second terminal, the first terminal 1b is It is equivalent to a telegram 9 in which identification information (TID) indicating the transmission from the first terminal 1b is set by waiting for the communication of the first terminal 1a to be completed and the line being opened by the selective activation means 2. It works like sending a message. The same applies to the case where an event to be reported to the first terminal 1a occurs while the first terminal 1b is performing data communication. Further, although the embodiment of the present invention shows the case where the two first terminals 1a and 1b are connected, the present invention is not particularly limited to the number of the first terminals.

As described above, in the line terminal system of the present invention, the second terminal 5 always selects the first terminal 1a or 1b to be communicated by the selective starting means 7 and opens the line by the terminating means 24. Until then, it operates so as to occupy a line and perform data communication for communication with the first terminal 1a or 1b. When the first terminal 1a or 1b needs to communicate with the second terminal, the first terminal 1a or 1b determines whether the line is used by the selected activation means 3 and the terminated means 17. If the line is not used, the selective activation requesting means 2 requests the second terminal 5 to start communication, and the selective activation request accepting means 6 of the second terminal 5 detects this request. On the contrary, by selecting the existing first terminal by the selection starting means 7, the data communication is performed.

[0026]

As described above, the line terminal system of the present invention has the following effects. (1) Since the first terminal such as a plurality of city gas meters can be connected by the terminal network control device (second terminal) equipped with the electrical interface necessary for connecting one first terminal, it is inexpensive. Various systems can be built. (2) The first terminal of low power consumption that realizes 1-to-n communication without the second terminal like the polling / selection method having to constantly solicit periodical transmission to each first terminal And a second terminal can be realized. (3) Since it can be realized by almost the same means as the conventional communication means of the first terminal and the second terminal, the microprogram does not increase significantly.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram of communication operation of the system.

FIG. 3 is another explanatory diagram of the communication operation of the system.

FIG. 4 is a block configuration diagram of a conventional line terminal system.

FIG. 5 is an explanatory diagram of communication operation of the system.

FIG. 6 is another explanatory diagram of the communication operation of the system.

[Explanation of symbols]

 1a, 1b 1st terminal 2 selective start request means 3 selected start means 4 extended slave control means 5 second terminal 6 selective start request acceptance means 7 selective start means 8 extended main control means 15, 23 data receiving means 16, 22 data transmission means 17 end means 24 end means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Sakata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A line terminal system in which a plurality of first terminals are branched and connected to the same line to communicate with a second terminal, the second terminal selecting one of the first terminals, First
First activating means for occupying a line and requesting the start of communication for communication with the terminal, and terminating means for releasing the occupied line by the selective activating means and terminating communication with the first terminal; Selective activation request acceptance means for accepting a request to start communication from the terminal, data transmission means for the first terminal selected by the selective activation means, and data reception means for the first terminal selected by the selective activation means. , The first terminal detects whether or not it has been selected by the selection activation means, and when the other first terminal is selected, the other first terminal
And the selected start-up means for determining that the line is occupied for communication with the other terminal and the communication with the second terminal or the communication between the second terminal and the other first terminal is completed To the second terminal only when the line to be terminated is detected because the terminated means for detecting the release and each first terminal prompts the second terminal to start communication by using the selective starting means. A line terminal system comprising a selective activation requesting means for requesting communication start, a data receiving means from a second terminal, and a data transmitting means to a second terminal.