JPH0480581B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a relay device that connects a communication device and a plurality of terminal devices that are connected via different types of communication lines.

(Background technology) Conventionally, in order to control in real time from a remote location multiple terminal devices connected to an on-premise data communication line (hereinafter referred to as an on-premise line) provided mainly for on-premises use. A relay device is used to connect the remote line and the local line in real time.

Examples of system configurations in which the above relay device is used are shown in FIGS. 1a to 1c. FIG. 1a shows an example in which the relay device 3 is used as a backup device for the communication control device 7. During normal operation, the communication device 1 and the communication control device 7 are connected via a specific communication line 6 to the terminal device 5.
-1 to 5-n are exchanged, and the communication control device 7 controls the terminal devices 5-1 to 5-n via the private line 4 in accordance with the above-mentioned control information. If the specific communication line 6 becomes unusable due to a failure, the line switching device 8 uses the public telephone network 9 as a backup line and performs similar control. Furthermore, when the communication control device 7 becomes unusable due to a failure, the line switching device 8 switches to the relay device 3 side, and the communication device 1 converts the electrical level between the public telephone network 9 and the private line 4 via the public telephone network 9. and a relay device 3 that only performs data and timing correction.
A terminal device 5- connected to the private line 4 via
1 to 5-n are remotely controlled from a remote location.

FIG. 1b shows an example in which the relay device 3 is used as a normal operation device and a backup device, and during normal operation, the communication device 1 connects the specific communication line 6 and the premises line 4 via the specific communication line 6. The terminal devices 5-1 to 5-n connected to the local area line 4 are remotely controlled from a remote location via the relay device 3 on the normal operation side that only performs level conversion and correction of data and timing. At this time, the line switching device 8 has been switched to the relay device 3 on the normal operation side. In addition, if a failure occurs in the specific communication line 6 or in the relay device 3 on the normal operation side, the communication device 1 or operator etc.
is switched to the relay device 3 on the backup side, and the communication device 1 connects to the private line 4 via the public telephone network 9 via the relay device 3 on the backup side, as in the case described above. -5-n are remotely controlled from a remote location. At this time, if the operator etc. switches to the backup side,
A call may be made from the relay device 3 to the communication device 1.

FIG. 1c is an example of the system shown in FIG. 1b without the backup device, and the operation is the same as that in FIG. 1b.

Further, in FIG. 1, in a system that requires a line switching device 8, the line switching device 8 is built into the relay device 3.

FIG. 2 is a block diagram of the conventional relay device 3 shown in FIG. The carrier (CD) detection circuit from the line, 3-3, sends the received data from the remote line to the local line only when the carrier is on, and sends the received data from the local line to the remote line, and when the carrier is off. The switching circuit 3-4 sets the non-communication state to the switching circuit 3.
-3, the received data from the remote line is sampled in accordance with the timing of the remote line, and the timing error with the local line is calculated using FIFO.
etc., and sends it to the premises line at the timing of the premises line, and the received data from the premises line that has passed through the premises electrical level conversion circuit 3-5 is sampled according to the timing of the premises line, and is transmitted to the remote line. The timing error with
Received data identification and regeneration circuit that buffers it using FIFO etc. and sends it to the remote line at the timing of the remote line, and corrects the data and timing between the remote line and the premises line. 3-5 is an electrical level conversion circuit with the premises line. It is.

By adopting the configuration of the relay device as described above, as shown in FIG. can be controlled remotely from a remote location, backup equipment can be realized at low cost by using a relay device, and low-cost relay devices are popular in small-scale campus systems with a small number of terminals and a light load. It is used for.

However, such conventional relay devices have the following problems.

(a) Control is carried out by carrier signals from the remote line, and when controlling a terminal device remotely on a specific communication line, it is always in a point-to-point configuration, making it impossible to use a multi-drop configuration. There is a problem.

(b) Public telephone networks cannot automatically check the ID of the other party when receiving a call, and there is a possibility that an incorrect call may be made when making a manual call. It becomes a factor.

(c) Poor line quality and low processing capacity.

(d) Because the remote line uses a specified communication line or public telephone network, the communication speed is low (about 1200 b/s on the public telephone network), so the terminal device must control at a high communication speed. figure,
Processing time will be slower.

(e) If the system configuration shown in Figure 1a is operated at the normal high-speed communication speed, it may be necessary to reconfigure the communication speed setting of the terminal device when back-up operation is performed, and the processing time may be reduced. As a result, the throughput of the entire system decreases.

(Object of the Invention) In order to eliminate the above-mentioned drawbacks, the object of the invention is to realize a relay device that can connect a digital circuit switching network as a remote line, thereby increasing communication speed and improving line quality. This is to prevent erroneous connections due to erroneous calls and to maintain call and re-call intervals by having an automatic call control function and ID check function within the relay device.
Furthermore, by holding a plurality of pieces of ID setting information in a relay device, a plurality of communication devices can control a terminal device connected to a private line.

The key point of this invention is that instead of the carrier detection circuit, specific communication line, and electrical level conversion circuit for connection with the public telephone network of the conventional relay device, automatic call control function and disconnection instruction monitoring function with digital circuit switching network are provided. , a connection control circuit that maintains a recovery request control function and an ID check function, and an electrical level exchange circuit with the digital circuit switching network are installed, making it possible to connect the digital circuit switching network as a remote line.
The check function makes it possible to prevent erroneous calls.
The automatic call function prevents inadvertent call operations by operators, etc. by maintaining the call and re-call intervals.
A setting information circuit consisting of ROM etc. is provided,
It is possible to set multiple IDs, and multiple communication devices can control terminal devices connected to a private line.

(Structure and operation of the invention) Hereinafter, the present invention will be described in detail according to embodiments with reference to the drawings.

Figures 3a to 3c are examples of system configurations using the relay device according to the present invention;
~c. That is, Figure 3a is the first
Figure 3a shows an example of a system configuration in which the public telephone network 9 is replaced with a digital circuit switched network 2 and a relay device 10 according to the present invention is used, and Figure 3b shows the public telephone network 9 in Figure 1a and a conventional system connected thereto. The relay devices 3 are connected to the digital circuit switching network 2, respectively.
FIG. 3c is an example of a system configuration in which the specific communication line 6 in FIG. 1c is replaced with the digital line switching network 2 and the relay device 10 according to the present invention is used. . In the system shown in FIG. 3 that requires the line switching device 8, the line switching device 8 is built into the relay device 10.

Since the operations of the relay device 10 according to the present invention in the system configuration examples shown in FIGS. 3a, 3b, and 3c are similar, the system configuration example in FIG. This will be explained below using FIG. 4, which is a diagram.

In FIG. 4, 10-1 is an electrical level conversion circuit for connecting to the digital circuit switching network 2, which replaces the electrical level conversion circuit for connecting to the conventional specific communication line and public telephone network, and 10-6 is the electrical level conversion circuit for connecting to the digital circuit switching network 2. 10-7 is a connection control circuit that has automatic call control function, disconnection instruction monitoring function, recovery request control function, and ID check function. 10-8 is a man-machine interface circuit that displays the status of the relay device to the operator and interfaces with the operation;
10-3 is connected to the digital circuit switching network 2 on the one hand;
identifies and reproduces the received data from the local area line 4, and sends it to the private line 4 (sampling the received data at the timing of the digital circuit switching network 2, buffering the timing error with the local line 4 using FIFO, etc.), and transmitting it to the private line 4. and sends the received data.)
On the other hand, the received data from the line is identified and regenerated and sent to the digital circuit switching network 2 (the received data is sampled at the timing of the private line 4, and the data is sent to the digital circuit switching network 2. 10-4 is a switching circuit that determines whether to buffer the timing errors using FIFO or the like and send out the received data at the timing of the digital circuit switching network 2, or to create a non-communication state; A received data identification and regeneration circuit identifies and reproduces received data and sends it to the private line 4, and identifies and reproduces received data from the private line 4 and sends it to the digital circuit switching network 2. 10-5 is an electrical connection with the private line 4. This is a level conversion circuit.

The relay device 10 initially receives interface regulation information (direct call, item, notification of other party, etc.) with the digital circuit switching network 2 through the setting information circuit 10-7.
is read, and the following operations begin according to that information.
In FIG. 3c, when the digital circuit switching network 2 and the relay device 10 are in a disconnected state (that is, when the communication device 1 is not controlling the terminal devices 5-1 to 5-n),
Connection control circuit 10- of the relay device 10 shown in FIG.
6 sets the switching circuit 10-3 to a no-communication state (for example, mark, idle, etc.), sends the no-communication state to the local line 4, ignores the data received from the local line, and sets the switching circuit 10-3 to a no-communication state (for example, mark, idle, etc.). 6 interfaces with the digital circuit switching network 2. At this time, the connection control circuit 10-6 monitors incoming calls from the digital circuit switching network 2 and calling instructions from the operator or the like. This state is called state 1. At this time, when an incoming call is received from the digital circuit switching network 2, the connection control circuit 10
-6 starts the call receiving operation. The state from the start of the incoming call operation until communication is possible is defined as state 2. During state 2, call instructions from the operator etc. are ignored. During the call control operation, if an abnormal call arrival sequence or network abnormality is detected, the state returns to state 1 again after the disconnection instruction sequence or recovery request sequence is performed. Also, during the incoming call control operation, if the other party is notified according to the interface regulation information with the digital circuit switching network 2, the ID is checked according to the setting information circuit 10-7, and the ID received as a result of the ID check is the third ID.
If it is not the communication device 1 that remotely controls the terminal devices 5-1 to 5-n in FIG.
Return to Here, if there is a plurality of communication devices 1 that remotely control the terminal devices 5-1 to 5-n, a plurality of ID checks are performed according to the setting information circuit 10-7, and the plurality of IDs to which the received ID is set are If it is not one of the IDs, the operation returns to state 1 in the same manner as described above. Further, as a result of the ID check, if the received ID is a communication device that controls the terminal devices 5-1 to 5-n, the incoming call control operation is performed normally and the state shifts to a communicable state. The state during communication is set to state 3. Alternatively, in state 1, when a call instruction from an operator or the like is received from the man-machine interface circuit, the connection control circuit 10-6 reads the ID information of the setting information circuit 10-7, and according to the ID, the digital circuit switching network 2 Start calling operation. The state from the start of the calling operation to the time when communication is possible is defined as state 2 as described above. During the call control operation, if an abnormal call sequence or network abnormality is detected, the state returns to state 1 again after the disconnection instruction sequence or recovery request sequence is performed. Further, during the call control operation, if a busy state (busy state) of the digital circuit switching network 2 or the communication device is detected, the re-call operation is automatically started after waiting for the re-call interval. At this time, if it is still busy even after re-calling twice, it waits for the time interval between calls, and then returns to state 1.
Return to Further, during operation in state 2, call instructions from the operator or the like are disabled, thereby preventing the operator or the like from inadvertently making a call to the digital circuit switching network 2. Further, although the automatic re-calling operation in response to an abnormal sequence during the above-mentioned call control operation depends on the level of the abnormality, it is possible if the setting information of the setting information circuit 10-7 is set to perform the automatic re-calling operation in the case of an abnormal sequence. be. Here, the terminal devices 5-1 to
If there are multiple communication devices that remotely control 5-n, the man-machine interface circuit 10
-8, the interface conditions set by the setting information circuit 10-7, the communication device setting information, etc., and confirm that there is no operator error (for example, if there are two communication devices, the communication After confirming that if device number 3 is specified, an error message will be displayed and the call will not be made, the call control operation will be started for the communication device number mentioned above. When the call origination control operation is successfully completed through the above operations, the state becomes communicable and shifts to state 3. In state 3, a call instruction by an operator or the like is invalid.

When transitioning to state 3, the connection control circuit 10-6 switches the switching circuit 10-3 from the non-communication state to the state where the received data from the digital circuit switching network 2 and the private circuit 4 are sent to each other's circuits, and the digital circuit switching starts. The received data from the network 2 is converted by the electrical level conversion circuit 10-1, and sent to the identification and reproducing circuit 10-4 through the switching circuit 10-3, where the received data is identified and reproduced, and the electrical level of the premises line is changed. The received data is sent to the conversion circuit 10-5, and after internal electrical level interface conversion, the received data starts to be sent to the local line 4. Further, the received data from the local area line 4 is converted by the electrical level conversion circuit 10-5, and sent to the received data identification and regeneration circuit 10-4, which identifies and reproduces the received data and sends it to the switching control circuit 10-3. . At this time, since the received data is valid, the received data is transferred to the electrical level conversion circuit 10.
-1, and after electrical level conversion with the digital circuit switching network 2, the received data begins to be transmitted to the digital circuit switching network 2. Due to this operation, during data transfer, communication device 1 and terminal devices 5-1 to 5-n
is capable of real-time communication operations, and a plurality of terminal devices connected to a private line can be remotely controlled from the communication device 1 from a remote location. Furthermore, at this time, the relay device 10 monitors the disconnection instruction from the digital circuit switching network 2 and the restoration request from the operator etc. by the connection control circuit 10-6.

As explained above, in state 3, the communication device 1 is connected to the terminal device 5-1 to 5-n connected to the private line 4 using the digital circuit switching network 2 as a remote line.
can be controlled remotely from a remote location.
At this time, it simultaneously monitors disconnection instructions from the digital circuit switching network 2 and recovery requests from operators, etc., and monitors to return to the non-communication state once the communication operation is completed. At this time, when a disconnection instruction is received from the digital circuit switching network 2 due to the termination of communication between the communication device 1 and the terminal devices 5-1 to 5-n, or a recovery request is received from an operator or the like. When sent, the connection control circuit 10-6 causes the switching circuit 1 to
0-3 to a non-communication state, invalidating the received data from the digital circuit switching network 2, and transmitting a communication-disabled state (for example, mark, idle, etc.) to the data communication line in the premises, and disabling the received data from the premises line 4. The connection control circuit 10-6 also performs a disconnection operation from the digital circuit switching network 2. After this operation, the digital circuit switching network 2
The process returns to state 1 in which incoming calls and outgoing call instructions are monitored.

Furthermore, in states 1 to 3, the display function of the man-machine interface circuit allows the relay device status, fault information, etc. to be displayed, making it possible for operators and the like to recognize the information.

By performing the above-described operation by the relay device 10, when the communication device 1 connected to the digital circuit switching network 2 and the relay device 10 are in a connected state, transmission data from the communication device 1 is transmitted to the private line 4 connected to the private line 4. The terminal devices 5-1 to 5-n can receive data, and the other party's communication device 1 can receive data transmitted from the terminal devices 5-1 to 5-n, and the other party's communication device 1 is connected to the digital circuit switching network 2. Communication operations between the communication device 1 and the terminal devices 5-1 to 5-n connected to the private line 4 are possible by providing the relay device 10, and the communication device 1 can use the digital circuit switching network as a remote line. Thus, the terminal devices 5-1 to 5-n can be controlled remotely from a remote location.

FIG. 5 shows a second embodiment of the relay device according to the present invention, in which the relay device 20 is provided with multiple functions so that it can be connected to a public telephone network, a specific communication line, and a digital circuit switching network. It is also possible to switch and use the switching circuit 10-9 as necessary by operation.

(Effects of the Invention) As explained above, the present invention provides a connection control means having an automatic call origination/reception control function, a disconnection instruction monitoring function, a recovery request control function, and an ID check function with a digital circuit switching network, and a digital circuit switching network. It is equipped with an electrical level conversion means for connecting to the network, a setting information means that holds setting information for multiple IDs, interface regulation information with the digital switched line network, etc., and further identifies data received from the digital switched line network in the same manner as in the past. Means for reproducing and transmitting the received data to the local line, identifying and reproducing the received data from the local line, and transmitting it to the digital line switching network; when the communication is not in the communication enabled state, the communication is in the non-communication state, and when the communication is in the communication enabled state, the digital line switching By providing a switching means for sending the received data from the network and the internal line to each other's line, and an electrical level conversion means with the internal line,
You can get the following effects.

(a) In a system that remotely controls multiple terminal devices connected to a premises line from a remote location, it becomes possible to construct a system that uses a digital circuit switching network as a remote line or as an operating line or a backup line.

(b) Compared to conventional systems, it is possible to increase the communication speed and improve the line quality, and as a result, the processing time of the system can be shortened.

(c) During normal operation, relatively high speed (e.g. 9600B/
If the communication speed is 48 KB/S), it is possible to operate at the same speed even when switching to a backup line, and there is no need to reconfigure the speed of the terminal device.

(d) The ID check function can prevent erroneous calls, and the automatic redial operation can prevent operators from making random calls.

(e) Multiple communication devices can remotely control a terminal device connected to a private line from a remote location.

[Brief explanation of the drawing]

1A to 1C are system configuration examples using a conventional relay device, FIG. 2 is a block diagram of a conventional relay device, and FIGS. 3A to 3C are system configuration examples using a relay device according to the present invention. FIG. 4 is a block diagram of one embodiment of the relay device according to the invention, and FIG. 5 is a block diagram of another embodiment of the invention. 1...Communication device, 2...Digital circuit switching network, 3...Relay device, 4...Internal line, 5-1~
5-n... terminal device, 6... specific communication line, 7...
... Communication control device, 8 ... Line switching device, 9 ... Public telephone network, 10, 20 ... Relay device, 3-1, 3
-5,10-1,10-5...Electrical level conversion circuit, 3-2...Carrier detection circuit, 3-3,1
0-3...Switching circuit, 3-4, 10-4...Received data identification and reproduction circuit, 10-6...Connection control circuit, 10-7...Setting information circuit, 10-8...Man-machine interface Circuit, 10-9...Switching circuit.

Claims (1)

[Claims] 1 A relay device that connects a digital circuit switching network to which at least one communication device is connected and a data communication line to which a plurality of terminal devices are connected,
a first converting means for mutually converting the electrical level of the digital circuit switching network and a predetermined level; a second converting means for mutually converting the electrical level of the data communication line and the predetermined level; means connected to the input of the converting means for identifying and reproducing received data from the digital circuit switching network and the data communication line and transmitting it to the other party; and a means connected between the means and the first converting means and said line a switching means for switching between a communication state and a non-communication state, a setting information means for holding a plurality of ID information and interface regulation information with the digital circuit switching network, and an interface for displaying and operating the relay device status to an operator. a man-machine interface means for aceing; and information from the means, information from the setting information means, and automatic call monitoring and disconnection instruction based on the ID of the communication device obtained from the output of the first conversion means. 1. A relay device comprising means for controlling said switching means by performing monitoring, restoration request control, and ID checking.