JPH05252298A - Terminal network controller - Google Patents

Abstract

PURPOSE:To make the system operation efficient by raising an alarm as to a state of redialing without increasing number of times of retrials in the system operation and without deteriorating the line utilizing efficiency when no line link is established or a talking error takes place. CONSTITUTION:When a link establish detection section 14 detects that a line link is not established after the transmission of a selection signal after the transmission of the selection signal, a 1st redial control section 21 decides number of times of line redialing. Furthermore, When a communication error detection section 16 detects an error at data communication, a 2nd redial control section 22 decides a line redialing. Then a selection signal transmission section 11 executes retrial under the control of a CPU 24. That is, the line redial number is controlled by the control sections 21, 22 depending on a fault cause. Thus, the line link is established by executing retrial for a prescribed number of times in the case of a line busy. Moreover, the control section 22 decides the line redial number on the occurrence of an error to enhance the line utilizing efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal network control device for a data communication system using a telephone network, etc., and particularly to redial control when a line link is not established or a communication error occurs. is there.

[0002]

2. Description of the Related Art A data communication system of this type is shown in a functional block diagram of FIG. The center device 1 is connected to a center side exchange 3 of an analog public line via a center side network control device 2. Then, the terminal network control device 6
Is connected to the terminal side exchange 4 of the analog public line 5. The telephone 7 and the data communication terminal 8 are connected to the terminal network control device 6. Here, the data communication terminal 8
Includes a meter having a contact signal for security and a communication function, or a home controller. The call from the terminal side, that is, the time call set in the terminal network control device 6 or the call by the data communication terminal 8 is connected according to the procedure of a normal telephone line service,
After the device on the center side and the device on the terminal side are connected, data communication is started according to the communication protocol defined by the system. Here, the data signal on the public line between the center side network control device 2 and the terminal network control device 6 is an analog signal usually called a modem signal, and the terminal side network control device 6 and the data communication terminal 8 are also provided. The data signals between are usually digital signals.

Next, a functional block diagram of the conventional terminal network control device 6 will be described with reference to FIG. A terminal network control device 6 is connected to the analog public line 5 via a dividing unit 9. The conventional terminal network control device 6 detects the establishment of a line link after transmission of a selection signal and a switching unit 10 for switching to the telephone 7, a network control unit 13 having a selection signal transmission unit 11 and a DC circuit closing unit 12. The link establishment detection unit 14, the data communication control unit 15, the communication error detection unit 16 that detects an error during data communication, and when the line link is not established by the link establishment detection unit 14, or by the communication error detection unit 16. A redial control unit 17 that redials when a communication error is detected, and a central control unit 1 that controls the above respective units.
8 and a data communication terminal interface section 19. The data communication terminal interface unit 1
A data communication terminal 8 is connected to 9. With this configuration, the redial control unit 17 is controlled by the central control unit 18 even when the line link is not established after the selection signal is transmitted, or when an error occurs during data communication, and redialing is performed a predetermined number of times. ..

[0004]

However, in the above-mentioned configuration, if the communication is not normally terminated, the line redial is performed a predetermined number of times regardless of any abnormality. That is, the retry due to the line busy may be performed a predetermined number of times to establish the line link, but when an error occurs during data communication, it may be difficult to recover naturally depending on the cause of the trouble. In this case, many retries cause a line busy condition for other terminals, lower the line utilization efficiency, and the user does not know what causes the communication not to end normally. I had.

An object of the present invention is to solve such a conventional problem, and to provide a terminal network control device which does not decrease the line utilization efficiency without increasing the number of retries in system operation. Is.

[0006]

In order to solve the above-mentioned problems, a terminal network control device of the present invention has an automatic dialing function and switches and connects a telephone line to one or more data communication terminals and a telephone. , A network control unit having a selection signal transmission unit and a DC circuit closure unit, a link establishment detection unit for detecting the establishment of a line link after the selection signal transmission, a data communication control unit, and an error during data communication is detected. A communication error detector, a first redial controller that redials when a line link is not established by the link establishment detector, a second redial controller that redials when a communication error is detected by the communication error detector, 1
The redial control unit or the second redial control unit includes an alarm unit for issuing an alarm or display output of redial control, and a central control unit for controlling each unit.

[0007]

According to the present invention, when the line link is not established by the link establishment detecting unit after the selection signal is transmitted, the first redial control unit and the communication error detecting unit detect an error during data communication. In this case, the second redial control section determines the number of line redials, and the central control section controls the selection signal transmission section. That is, the number of line redials is controlled by the first redial control unit and the second redial control unit for each cause of the abnormality, and the state of each redial control is alarmed or displayed by the alarm unit.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Referring to FIG. 1, a terminal network control device 2 of the present invention.
Reference numeral 0 is connected to the analog public line 5 via the dividing unit 9, and the switching unit 10 for switching the public line 5 to the telephone 7 and the data communication terminal 8 and the selection signal transmitting unit 11
And a network control unit 13 having a DC circuit closing unit 12, a link establishment detection unit 14 that detects establishment of a line link after sending a selection signal, a data communication control unit 15, and a communication error that detects an error during data communication. The detection unit 16, the first redial control unit 21 that redials when a line link is not established by the link establishment detection unit 14, and the second redial control unit 22 that redials when a communication error is detected by the communication error detection unit 16 An alarm unit 23 that gives an alarm or display output that redial control is performed by the first redial control unit 21 or the second redial control unit 22, and a central control unit 24 that controls each unit.
It comprises a data communication terminal interface unit 19. The data communication terminal 8 is connected to the data communication terminal interface section 19. Although one data communication terminal 8 is shown in the figure, a case where a plurality of data terminals such as a controller for security, a meter having a communication function, or a home controller is connected is also included.

With the above structure, in order to start the data communication by the terminal transmission, first, the DC circuit closing unit 12 off-hooks the telephone line to establish the communication path between the center apparatus and the terminal network control apparatus. The selection signal sending unit 11 dials the telephone number of the center device. Link establishment detector 1
When it is detected that the line link is established, that is, the telephone line is connected in 4, the data communication control unit 15 starts data communication. However, when the link establishment detecting unit 14 detects that the line link is not established, the central control unit 24 temporarily hooks the line on the network control unit 13 and controls the first redial control unit 21 to control the selection signal. To redial operation for resending. If the communication error detection unit 16 detects an error in data communication while the line is once established and data communication is started, the central control unit 24 causes the data communication control unit 15 to complete the data communication process. Then, the network control unit 13 once hooks the line on the hook, controls the second redial control unit 22, and shifts to the redial operation for retransmitting the selection signal. Then, the alarm unit 23 outputs an alarm or display that redial control is performed by the first redial control unit or the second redial control unit.

Next, the operation of this embodiment will be described with reference to FIGS. 2, 3 and 4.
Will be explained. 2 shows an operation sequence diagram during normal communication, FIG. 3 shows a redial operation sequence diagram when a line is not established, and FIG. 4 shows a redial operation sequence diagram when an error occurs during data communication. In each of the sequence diagrams, the horizontal axis represents elapsed time, the vertical axis is from top to bottom, and a. DC circuit closure, b. A selection signal transmitter, c. Data communication control unit (during reception), d. Data communication control unit (during transmission), e.
A first redial controller, f. A second redial controller, g. Shows the alarm section.

In the normal communication operation shown in FIG. 2, at time t1, the DC circuit closing portion operates to form a DC loop in the line,
Then, dialing is started in the selection signal transmitting section. Next, communication data (downward telegram) dat from the center side
a1 is received, and in response to this data content, the terminal network control device of the present invention sends upstream communication data (uplink data) data2.
Is sent. From the center, in order to convey the content of the normal communication, the data 3 of the downlink message is sent, the message is received, the DC circuit closing part is controlled via the central control unit, and the line is opened at t3. ..

In the redial operation when the line of FIG. 3 is not established, the circuit is closed at t3 as in FIG. 2 and the selection signal is sent. However, the downlink message has not been received even after the time T1 has elapsed after the selection signal was transmitted. That is, since the data does not arrive from the center even after the lapse of a predetermined time after dialing, the link establishment detection unit determines that the line has not been established, and at t4, the first redial control unit operates to open the line once. The alarm unit outputs the alarm signal after the control. After that, at time t5 when the time controlled by the first redial control unit has elapsed, the line is closed again and the selection signal is transmitted. The sequence up to t6 is the same as that described above, and the alarm signal is output from the alarm unit. Here, the timer T1 detects that the communication path is not established after the selection signal is sent. However, the function of the link establishment detecting unit can be realized by the method of detecting the polarity of the line or the busy tone. Further, although the alarm unit outputs the alarm signal each time the first redial control unit is activated, the alarm signal may be output after the first redial control unit has been activated a predetermined number of times. Further, in this figure, although the alarm or display signal output state from the alarm unit can be seen in a short period of time, there is also means for continuously outputting until the next redial operation or the normal termination of communication. As shown in this figure, when the communication path is not established, the first redial control unit and the alarm unit are activated to control the redialing operation. For example, there is a method of performing redial time three times per minute as one group for eight times in total every 30 minutes and outputting as a warning signal the number of times of redial operation.

In the redial operation when an error occurs during the data communication of FIG. 4, the line is closed at t7 as in the case of FIG. 2, and the data communication is started after the selection signal is transmitted. When the communication error detection unit 16 detects a data error (for example, a bit error, a parity error, etc.) while receiving the downlink message data4 from the center, at t8, the second redial control unit operates to activate the line. Once opened, the alarm unit outputs an alarm signal. After that, the line is closed again at t9 when the time controlled by the second redial control unit has elapsed, and the selection signal is transmitted. Below, t10 when an error occurs in data5
The sequence up to is the same as above. As shown in this figure, when a data error is detected during data communication, the second redial control unit operates to control the redialing operation and outputs an alarm signal. For example, the redial operation is performed 5 times in total. In this figure, only the line is opened when an error is detected. However, the line may be opened after the process of sending a retransmission request message or a rejection response message (NAK). .. Also, in the case where a high-priority communication processing interrupt occurs during data communication, communication that interrupts communication processing after the data processing currently in communication is terminated once, that is, interrupt processing is performed. It also includes errors.

In this way, determination of establishment of the communication line and
Each determination of a data communication error including a communication line failure and the like is performed, and the first and second redial control units operate according to the content of each abnormality, and the alarm unit outputs an alarm signal. Therefore, regardless of the type of abnormality, the line redial is not performed a predetermined number of times, and the busy state is not created unnecessarily, which does not lead to a decrease in line utilization efficiency and which state the user is in in data communication. Is effective.

Next, in the present embodiment, each alarm or display signal from the above-mentioned alarm unit can be output by the terminal network control device, but it is also possible to send it to the telephone side or the data communication terminal side. .. That is, to the telephone 7 side,
It is possible to notify the user of the abnormal state by converting the status of redialing into a voice synthesis or fax signal and transmitting it. Also, when sending to the data communication terminal side,
The home controller sends an alarm and transmits data for display.

As described above, by outputting the alarm signal to a device other than the terminal network control device, the user can recognize the abnormal information in the data communication control, and the convenience in the system operation is greatly improved.

Further, another embodiment of the present invention will be described with reference to FIG. The components having the same numbers as those in FIG. 1 have the same functions. The alarm unit 23 controls a first alarm control unit 25 that controls an alarm signal when redial control is performed by the first redial control unit, and a second alarm control unit that controls an alarm signal when redial control is performed by the second redial control unit. And the alarm control unit 26. 27
Is a central controller that controls these components.

With this configuration, the alarm or the display output can be varied for each factor of the first or second redial control, and the system user can confirm the content of the abnormality information, which is more convenient for dealing with the abnormality. Is.

Further, the effect is further enhanced by including the information of the dial destination or each connected data communication terminal and outputting the alarm.

In addition, the number of redials controlled by the second redial controller 22 when a communication error occurs is smaller than the number of redials controlled by the first redial controller 21 when a link is not established.
It is possible to reduce the line busy condition at the time of a line failure that is difficult to recover naturally, and the user can speed up the response by outputting an alarm.

[0022]

As described above, according to the line terminal device of the present invention, the following effects can be obtained. (1) When the line link is not established after the selection signal is transmitted by the link establishment detection unit after the selection signal is transmitted, when the first redial control unit detects an error during data communication by the communication error detection unit. The second redial control unit determines the number of line redials, and the selection signal transmission unit retries under the control of the central control unit. That is, the first redial control unit, and the second
The redial control unit controls the number of line redials for each cause of abnormality. Therefore, it is possible to establish the line link by performing the retry due to the line busy a predetermined number of times. In addition, when an error occurs during data communication, it may be difficult to recover naturally depending on the cause of the trouble.
Since the number of line redials is determined by the redial control unit, it is possible to prevent a line busy state from occurring to another terminal by inadvertently retrying and to suppress a decrease in line utilization efficiency. Further, since the line abnormal condition can be confirmed by the output signal from the alarm unit, the efficiency of system operation can be improved. (2) Each alarm or display signal from the alarm unit is sent to another device such as the telephone side or the data communication terminal side, so that the user can recognize the abnormal information in the data communication control and the system operation. The convenience is greatly improved. In other words, the redial status is converted to a voice synthesis or fax signal and sent to the telephone side, and when it is sent to the data communication terminal side, an alarm is issued or displayed by the home controller or the like. It is possible by transmitting the data of. (3) For each factor of the first or second redial control,
Since the alarm or the display output can be changed, the user of this system can confirm the content of the abnormality information according to the cause, which is more convenient for dealing with the abnormality.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a terminal network control device according to an embodiment of the present invention.

FIG. 2 is an operation sequence diagram during normal communication in the device.

FIG. 3 is a sequence diagram of a redial operation when a line is not established in the device.

FIG. 4 is a redial operation sequence diagram when an error occurs during data communication in the same device.

FIG. 5 is a functional block diagram of a terminal network controller according to another embodiment of the present invention.

FIG. 6 is a functional block diagram of a data communication system.

FIG. 7 is a functional block diagram of a terminal network control device in a conventional example.

[Explanation of symbols]

 5 analog public line 7 telephone 8 data communication terminal 11 selection signal sending part 12 DC circuit closing part 13 network control part 14 link establishment detecting part 15 data communication control part 16 communication error detecting part 21 first redial control part 22 second Redial control unit 23 Alarm unit 24, 27 Central control unit

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

Claims (3)

[Claims] 1. A terminal network control device having an automatic dialing function and switching and connecting a telephone line to one or more data communication terminals and telephones, the network having a selection signal transmitting section and a DC circuit closing section. A control unit, a link establishment detecting unit that detects establishment of a line link after sending a selection signal, a data communication control unit, a communication error detecting unit that detects an error during data communication, and the line establishment line by the link establishment detecting unit. A first redial control unit that redials when a link is not established, a second redial control unit that redials when a communication error is detected by the communication error detection unit, the first redial control unit or the second redial control unit.
2. A terminal network control device comprising an alarm unit for alarming or displaying output of redial control by the redial control unit, and a central control unit for controlling each unit. 2. The terminal network control device according to claim 1, wherein the alarm or display output of the alarm unit is sent to the telephone side or the data communication terminal side. 3. The alarm or the display output of the alarm unit is variable depending on whether the redial control is performed by the first redial control unit or the redial control is performed by the second redial control unit. Terminal network controller.