JPS63175555A - Line interrupting system - Google Patents

Abstract

PURPOSE:To avoid a state that a line is disconnected while data during transmission is stored tentatively by interrupting the line in receiving an interruption acknowledge message from an opposite party when a line interruption message is sent from a communication equipment to a communication party. CONSTITUTION:For example, a central management unit 10 and a supervisory equipment 11 or the like located at plural locations apart from the management unit 10 are included and the equipment has a function as a communication equipment connected via a public telephone line 12 and applying communication. When a line connected with one of two communication equipments during communication is desired to be interrupted, a line interruption message is sent to the communication opposite party from the communication equipment and when a message approving the interruption is received from the opposite party, the line is interrupted and in receiving a message rejecting the interruption, the line is not interrupted. Thus, the state that the data during transmission is stored tentatively in the communication equipment and the line is interrupted is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for disconnecting a line connected for communication between a plurality of communication devices.

[Prior Art] In recent years, as a system for communicating between multiple communication devices via a predetermined communication line, for example, group management, which allows multiple distributed buildings to be managed all at once in a specific central building, has become popular. system is provided. This group management system connects the center building's management device, which is equipped with communication equipment, with the monitoring devices of multiple remote buildings through dedicated communication lines, and provides environmental information and other information between the center building and each remote building. By transmitting data, management at each remote building can be automated or unmanned, contributing to lower management costs by saving energy and labor in each building.

[Problems to be solved by the invention] However, in the group management system as described above, depending on the scale of the remote building, it may not be necessary to transmit a large amount of data. It is uneconomical to use multiple communication lines, especially when many remote buildings are scattered over a wide area.
There was a problem that communication costs were high.

Therefore, a group management system that aims to reduce communication costs by using public lines as communication lines has been proposed.In this system, in order to minimize communication costs based on line connection time, When communication with the remote building monitoring device ends, the line is quickly disconnected.

However, in such conventional line disconnection methods, data is transmitted via a communication device including a control device such as a personal computer, so when the transmission and reception are completed at the center or remote side, the data being transmitted is There is a risk that the line will be disconnected while the data is temporarily stored in the device and the data will be lost. In addition, while repeatedly connecting/disconnecting the line each time data is sent/received increases communication costs, it is useful when you want to maintain the line connection even when no data is being sent/received, such as during debugging or emergency operations. There was a problem in that it was inconvenient for the line to be disconnected.

[Means for Solving the Problems] The present invention provides a communication system in which a plurality of communication devices as described above are connected via a communication line to perform transmission and reception, in which data transmission from one of the communication devices to the other is completed. An object of the present invention is to provide a line disconnection method that solves the above problems by not immediately disconnecting the line.

Therefore, in the present invention, when one of two communication devices that is communicating wants to disconnect a line connected to it, the communication device sends a line disconnection message to the other party, and the other party sends a message acknowledging the disconnection. When a message is received, the line is disconnected, and when a message refusing disconnection is received, the line is not disconnected.

More specifically, the problem of the line being disconnected while the data being transmitted remains in the communication device can be solved by mutually confirming the disconnection of the line between the communication devices and then disconnecting the line. In addition, as mentioned above, connecting a line every time data is sent and received increases communication costs, but this point is resolved by monitoring the no-communication time and disconnecting the line.In other words, when no communication continues for a certain period of time, the line is disconnected. This will reduce the risk.

Furthermore, if you want to maintain the line connection even when no data is being sent or received, such as during debugging or emergency operations, you can refuse to disconnect, but if you continue to refuse to disconnect, you will be unable to disconnect forever, so the other party can refuse. A disconnection that cannot be performed (forced disconnection) is also available, and in the case of forced disconnection, it is also possible to prohibit the other station from connecting to the line for a certain period of time (this time is variable and specified at the time of forced disconnection).

[Embodiment] FIG. 1 shows a group management system implementing the line disconnection method of the present invention. This system includes a central management device 10 installed at a specific location (for example, a center building) and monitoring devices M11 installed at multiple locations (for example, remote buildings) apart from this central management device 10. The device has a function as a communication device that connects via the public telephone line 12 and performs communication. Also, as a communication control device that performs connection and other communication control between the central management device 10 and the monitoring device 11, the central management device 10 and the monitoring device 1 of the communication partner
1 via the public line 12.
1ine (hereinafter referred to as GWS) 13 and this GWS 1
3 to the public line 12. In addition, the communication adapter 14 is
In order to connect the monitoring device 11 to the public line 12, it is also provided on each monitoring device 11 side.

Next, as shown in FIG. 2, the central management device 10 includes an operator console (OPU) 21 and sub-operator consoles that are operated by building supervisors or operators to monitor each building (including the center building) and collect data. (SOPU) 22, a main console (MCL) 23 which is a control unit of this system, and a communication network 24 that connects these.

The operator console 21 includes a main man-machine unit (MMU) as a module connected to the communication network 24.
) contains 25. The two attached MMU25s are
It controls the CRT 26 and the message printer (MPR) 27, respectively, and can separate the operational categories from each other. If one of them is abnormal, the MPR 27 is switched and the operational category is backed up. A hard copy printer (HCP) 28 can be connected to the CRT 26 for printing displayed contents. Note that the operator console 21 includes
It also includes a graphics driver (GDR) 29 connected to the main console 23, which includes input pushbuttons 3.
0 and an output display 31 are connected.

The sub-operator console 22 includes a sub-man-machine unit (SMU) 32 which is equivalent to the MMU 25 but is installed at a different location such as a sub-center or disaster prevention center.
RT26 and MPR27 are connected.

The main console 23 includes a main control unit (MCU) 33 and a distributed control unit (DCU) 34 as modules connected to the communication network 24 . MCU33
is a magnetic disk (MD) or flexible disk (F
Equipped with an external storage device such as D) and a logging printer (LPR), it processes and accumulates management data, manages and distributes system-shared data, and also performs global (spanning multiple DCUs) control and system processing. govern

On the other hand, the DCU 34 is distributed in a distributed manner in terms of the number of management points and placement locations, and communicates with various equipment such as heat sources, air conditioning, and electric power, and performs alarm detection, power failure/recovery control, various energy saving controls, etc. Let's do it.

Further, the communication network 24 uses optical fiber as a communication medium, has a ring structure, and can adopt high-level data link control (HDLC) as a protocol (communication protocol).

Furthermore, the GWSL 3 and communication adapter 14 for public line connection are configured as shown in FIG. That is, the GWS 13 has a plurality of communication channels (for example, 8 channels), and has a communication interface 4 for connecting to the communication network 24 and the adapter 14, respectively.
1 and 42, a storage unit 43 that stores the above-mentioned protocols and other necessary communication control procedures, and a CPU 44 that transmits bus messages from the communication network 24 to the building monitoring device 11 and performs other communication control according to the communication control procedures.
It is composed of: The data given to the GWS 13 in advance includes the telephone number of the communication destination, the setting of the incoming and outgoing channels, the model of each station (MMU, MCU, DCU), etc.

The adapter 14 also includes a communication interface 45 for transmitting and receiving signals with the GWS 13, a processor 46 that performs processing necessary for connection to the public line 12, etc.
Automatic call/receive NCU activated when calling the communication partner
(Network control unit) 47 and a modem 48 that is activated after a line is connected to a communication partner. Such a communication adapter is known as a personal computer adapter with a built-in microprocessor, and is also placed on the remote building side.

Note that the above GWS 13 has multiple communication channels (e.g. 8 channels), and 5DUs 51 (described later) can be connected to each channel via the adapter 14, so if there are many SDUs, 2 or more communication channels can be connected. It is also possible to provide several GWSs.

In addition, in this group management system, the monitoring device 11 in each remote building monitors a large amount of data such as heat sources, and in order to collect and analyze this data, a personal computer 35 is installed at the center as shown in FIG. It is connected to the public line 12 via a communication adapter 14.

On the other hand, the monitoring devices 11 each have a public line connection distributed control device (
SDU) 51, and accompanying CRTs, printers, etc. Similar to the DCU 34 on the center building side, the 5DU 51 communicates with various equipment such as heat sources, air conditioning, and electric power in the remote building where it is located, and performs alarm detection, power failure/recovery control, various energy saving controls, etc. It also has the function of communicating with the central management device 10 via. That is,
Each 5DU 51 has a communication interface 5 for connecting with an adapter 14 on the remote building side, as shown in FIG.
2, a storage unit 53 that stores communication control and other necessary procedures for various equipment in the remote building and the central management device 10;
A CPU 54 that monitors remote buildings and communicates with the central management device 10 according to the stored procedures;
Man-machine interface 55 for connection with computers, printers, etc.
It is composed of:

Next, in the group management system configured as described in section 2, by using the line disconnection method of the present invention, the center side MMU
The operation when disconnecting the line connection between a device such as 25 or the like and the remote monitoring device 11 will be described.

Figure 5 shows GWS13, which is the communication control device on the center side.
shows the operation. This operation begins when the line is connected. First, as shown in FIG. 5(A), GWS 1
3 starts the first 1 minute timer. This one-minute timer is used to send a normal disconnection message (described later) to the other station (5DU on the remote side in this case) when a certain period of time (one minute in this case) has elapsed since the line was connected.

Next, GWS I 3 determines whether the line has been disconnected. In the case of "Yes", as shown in FIG. 5 (B), the connector ■ stops the first one-minute timer and checks whether the disconnection is due to an abnormality in the line network.
If “Yes”, it is determined that the disconnection is due to a network abnormality, and N
If it is "O", it is determined that the other party (remote side) is abnormal and the operation ends.

On the other hand, if the line is not disconnected, then it is determined whether the conditions for forced disconnection are met.

The condition is, for example, when a forced disconnection request is issued by a user (in this case, the MMU 25 operated by an operator at the center, or the MCU 33 or DCU 34 as a communication station; the same applies hereinafter). , for example, in the following cases.

In a communication device such as this GWS 13 that receives line connections from multiple 5DUs 51, if the frequency of line connections with a specific 5DU 51 is high, communication with other SDUs will be hindered, so in order to avoid this, This is a case where line connection from a specific SDU is prohibited for a certain period of time under certain conditions, and the connection line is forcibly disconnected.

When the above-mentioned forced disconnection conditions are satisfied, the GWS 13 performs the operation shown in FIG. 5(C) using the connector (2). That is, the first one-minute timer is stopped, a forced disconnection message is sent to the other party 5D051, and the second one-minute timer is started. This second one-minute timer indicates that if there is no response to a disconnection request (forced or normal disconnection message) within a certain period of time (one minute in this case) after the end of transmission and reception with the remote side, the other party is abnormal. This is for the center to make a judgment and disconnect the line.

GWS 13 then determines whether the line has been disconnected, and if "Yes", stops the second one-minute timer. Then, as shown by the connector ■, the disconnection due to line network abnormality in Figure 5 (B) is checked. If ``Yes'', it is determined that the disconnection is due to line network abnormality, and if ``NO'', the other party ( (Remote side) It is determined that there is an error and the operation ends.

On the other hand, if the line is not disconnected, it is determined whether data has been received next. When data is received, it is checked to see if it is normal data, and if "No", it is determined that abnormal data has been received, and the process returns to the line disconnection check operation described in section 2 (connector ■). Also, when normal data is received, it is determined whether it is data that should be passed on to the user (identification information is added to the transmitted/received data), and if it is "Yes", the data is received to the user. is notified and returns to the second timer start mentioned above (connector ■). If "No" (if disconnection is accepted from the remote side), the second 1-minute timer is stopped and from yourself (GWS) The line is disconnected and the operation ends.

If no data is received, the second 1-minute timer determines whether or not it fires, and if it does not fire,
Return to the line disconnection check operation described above. When this timer fires, that is, when there is no line disconnection or data reception for one minute, the fifth
Perform the operation shown in figure (D). That is, the user determines that there is an abnormality on the other end (for example, the remote monitoring device 11 is not operating normally due to a failure) and disconnects the line.

On the other hand, if the condition for forced disconnection is not satisfied in Figure 5 (A), it is determined whether data has been received next, and if "Yes", the connector ■ is shown in Figure 5 (D). Perform the action. First, it is checked whether the data is normal or not, and if "No", it is determined that abnormal data has been received, and the process returns to the line disconnection check operation shown in FIG. 5(A) (connector ■). When normal data is received, it is determined whether it is data that should be passed to the user or not, and if it is "Yes", the user is notified of the data reception and the first timer start shown in Fig. 5 (A) is executed. Return (connector ■), if “No”, check whether it is a forced disconnection message and return “No”.
” (in the case of normal disconnection), it is determined whether the conditions for refusing disconnection are met.The conditions are, for example, when the user issues a request to send data or continue line connection. When the disconnection refusal condition is satisfied, a disconnection refusal message is sent and the process returns to the first timer start in FIG. 5(A) (connector ■).

On the other hand, in the case of a forced disconnection message or if the conditions for refusing disconnection are not met, the first one-minute timer is stopped, a disconnection approval message is sent, and the second one-minute timer is started. Then, it is determined whether the line has been disconnected, and if it has been disconnected, it is checked whether the disconnection is due to an abnormality in the line network. It is determined that the disconnection is normal and the operation ends. Also, if the line is not disconnected, the second
It is determined whether the 1-minute timer is on fire or not, and if it is not on fire, the process returns to the line disconnection check operation described above.

When this timer fires, it is determined that there is an error on the other end (remote side), and the line is disconnected, and the operation ends.

On the other hand, if no data is received in Figure 5 (A), it is determined whether there is a data transmission request from the user, and if "Yes", the connector [phase] is
) and return to the initial state (
Connector ■): If there is no data transmission request from the user, check whether the first one-minute timer has fired. If the first one-minute timer does not fire, the circuit returns to the line disconnection check operation (connector ■), but if it fires, the connecter ■ performs the operation shown in FIG. 5(F).

First, it is determined whether the conditions for continuing the connection are met. The condition is, for example, when a user requests data transmission or line connection continuation. When these conditions are met, the state returns to the state before the start of the first timer in Figure 5 (A) (connector ■); however, if the conditions for continued connection are not met, the first one-minute timer starts. stop and
Sends a normal disconnection message and starts a second one-minute timer.

Next, the GWS 13 determines whether the line has been disconnected, and if "Yes", stops the second one-minute timer. Then, check for disconnection due to line network abnormality as shown in Figure 5 (B) indicated by connector ■. If "Yes", it is determined that the disconnection is due to line network abnormality, and if "No", the other party (remote side) It is determined that there is an abnormality and the operation ends.

On the other hand, if the line is not disconnected, it is then determined whether data has been received. When data is received, it is checked to see if it is normal data, and if "No", it is determined that abnormal data has been received and the process returns to the line disconnection check operation (connector ■). Also, when normal data is received,
Determine whether it is data that should be passed to the user, and
eS”, the user is notified of data reception and the second
Returning to the minute timer start (connector o), if "No", it is determined whether the received data (signal) is a disconnection acknowledgment message from the remote side. As a result, if it is not a disconnection approval message, ζ (rejection of disconnection) returns to the first timer start in FIG.
The operation ends when you disconnect the line from yourself (GWS).

As described above, in the GWS 13, when a predetermined time (one minute in this example) has elapsed after the line was connected, or when the conditions for forced disconnection are met, the 5DU of the communication partner station is
51 to disconnect the line (forcible or normal disconnection), and after obtaining consent from the other party, the line is disconnected.

On the other hand, in 5DU51, which is a communication control device on the remote side, the GWS l shown in FIGS.
The operation is the same as No. 3. In other words, in 5DU51, when a predetermined period of time (3 minutes in this case) has elapsed since the line was connected, a line disconnection message (forced or normal disconnection) is sent to the other party's (center side) GWS 13, and it is determined that the line is not forcibly disconnected. Whenever possible, I try to get the other party's consent before disconnecting the line. Here, the reason why we set the time to 3 minutes is that the decision whether or not to disconnect the connected line is basically left to the judgment of GWSl 3 on the center side after 1 minute has passed, and the remote side In 5DU51, GWS l 3
This is to perform the above-mentioned line disconnection function in an auxiliary manner when the line does not operate normally due to breakdown or repair. Further, in this system, the time is set to 1 minute and 3 minutes, but this may be changed depending on communication costs and the like.

Note that the user (for the SDU 51) in this case is a terminal device (including an operator) for transmitting and receiving data on the remote side.

Although the embodiments have been described above, the present invention is not limited thereto. For example, as the communication control equipment used in the present invention, means other than the GWS configured as described above and a personal computer adapter may be used. Further, although the illustrated system monitors a plurality of remote buildings in a central building, the line disconnection method of the present invention can be applied to systems other than building management.

[Effects of the Invention] As described above, according to the present invention, when one of two communication devices in communication wants to disconnect a connected line, the communication device sends a line disconnection message to the communication partner, The line is disconnected when a disconnection acknowledgment message is received from the other party, which prevents the line from being disconnected while the data being transmitted is temporarily stored in the communication device.
Further, even if data transmission is finished, if you want to send and receive data with the same party, you can continue sending and receiving data without disconnecting the line.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a group management system that implements the present invention, FIG. 2 is a diagram showing the components of the system in FIG. FIG. 5 is a diagram showing an example of the configuration of a remote-side monitoring device, and FIG. 5 is a flowchart showing the operation of the communication control device using the line disconnection method of the present invention. 10-- Central management device, 11-- Monitoring device, 12-- Public telephone line, 13-- Public line gateway (GWS), 14-
---1 communication adapter, 21--operator console, 22--1 sub-operator console, 23--1 main console, 24--1 communication network, 25--Man-machine device (MMU) ), 32 --- One secondary man-machine unit (SMU), 33 --- One main controller (MCU), 34 --- One distributed controller (D CU), 35 ---
Personal computer, 51--1 public line communication control unit (SDU).

Claims (1)

[Claims] In the disconnection method for lines connected for communication between multiple communication devices, if one of the two communication devices that is communicating wants to disconnect the line, the communication device must A line disconnection method characterized by transmitting a line disconnection message and disconnecting the line when a disconnection acknowledgment message is received from the other party.