JPS593641Y2 - data transmission equipment - Google Patents

Description

[Detailed description of the invention] This invention is a data transmission system in which multiple terminal stations share a line, and when the line is occupied and no legitimate received data is input for a certain period of time, an alarm is issued for a certain period of time. , and relates to a data transmission device in which such occupied station is removed from line occupation.

When a central control station and multiple terminal stations share a line (telephone line, etc.), for example, information specifying transmitting/receiving terminal stations, signals indicating priority, signals for exclusive control of the line, data bit signals for transmission purposes, hand In a system that mutually transmits data consisting of seek signals (accompanied by data exchange, etc.), for example, a local station sends out a call signal to monopolize the line with a specific partner station, and When data is transmitted to a station, the other station generally sends back an acknowledgment signal indicating that the data has been received.

When the station on the data transmission side confirms this clearance signal, it releases the occupied line and makes the line empty.

By the way, if the other station does not send data within a certain period of time even though the line is occupied, or if data is sent but it is not legitimate data, data cannot be exchanged. For this reason, the transmission does not end and the occupied line becomes abnormal.

Conventionally, when a line-occupying station malfunctions like this,
By issuing an alarm signal, the communication state is stopped, and special actions (
It is designed to recover only after a reset, etc.).

Therefore, as long as this abnormal condition continues, there is a drawback that the line will continue to be occupied by the non-emergency box.

However, the present invention eliminates the drawbacks of the conventional device, and embodiments thereof will be described below with reference to the drawings.

FIG. 1 shows the relationship of a transmission system between a central control station and terminal stations that share a line.A central control station 1 is connected to a plurality of terminal stations 2, 2/, 2//,・・・・・・
...indicates a state where they are connected in parallel.

Next, the configuration and operation of the terminal station shown in FIG. 1 will be explained using the block diagram shown in FIG. 2.

First, to describe the configuration of the terminal station, for line 3,
A circuit 11 is connected to determine whether or not the received signal is regular data, and a circuit 12 is connected to the same data determination circuit 11 to determine whether or not regular data has been received within a certain period of time. has been done.

In addition, the reception discrimination circuit 12 is activated by an output signal from the reception discrimination circuit 12 when a regular date is not received within a certain period of time, and is regulated to issue an alarm for a certain period of time. A circuit 14 is connected which transmits an alarm signal to the other station via the line 3 by the operation of the timer 13.

Furthermore, after transmitting the alarm signal for a certain period of time, the alarm signal transmitting circuit 14 is newly transmitted.
A circuit 15 is connected to the circuit 15, which is driven by an output signal generated by the line 3 and sends a release signal to remove the occupancy of the line 3. - The communication function circuit 16 is connected.

On the other hand, the line occupation removal circuit 15 includes a receiving circuit 17 for receiving an alarm signal issued by another terminal station (destination station).
is connected via line 3, and this alarm signal receiving circuit 17
The line occupancy removal circuit 15 is driven in the same way by the output of , and furthermore, the communication function of the occupancy/communication function circuit 16 is cut off by the output signal, and the circuit 18 for displaying the occupancy state is connected. has been done.

Next, the operation of the terminal station according to the above configuration will be explained in detail.

Now, in the line occupancy state, the occupancy/communication function circuit 16 operates, requests the partner station to transmit data via the line 3, and then enters the reception state.

On the other hand, if regular data is not transmitted from the other station for a certain period of time or more, the reception discrimination circuit 12 generates an output, and the output signal drives the alarm signal generation circuit 14 to generate an alarm signal. .

An alarm signal (that is, an abnormal signal) for only a certain period of time is transmitted to the other station via the line 3, whose termination is regulated by the timer 13 started by the alarm signal.

By receiving this alarm signal, the function of releasing the line from the occupied state is activated in the other station.

Further, when the transmission of this alarm signal passes a certain period of time according to the end time regulation of the timer 13, a new output from the alarm signal transmission circuit 14 (a falling signal of the alarm signal itself may be used).

), and its output drives the line occupancy removal circuit 15 for removing the occupied state of the line 3, and further, the output from the line occupancy removal circuit 15 causes the occupancy/communication function circuit 16 to stop its communication function. Then, the terminal station's own use of line 3 is returned to an idle line.

In this operation, the line occupancy removal circuit 15 is directly driven by the new output of the alarm signal transmitting circuit 14 at the end of the alarm signal, and the alarm signal transmitted to the line 3 by the alarm signal transmitting circuit 14 is also activated when the alarm signal is terminated. Since the output from the alarm receiving circuit 17 is operated redundantly due to being received by the receiving circuit 17, there is no adverse effect due to this, and the reliability of line occupancy removal is improved.

Further, even if a data is transmitted from the other station in the above-mentioned reception state related to line occupation, it may not be a legitimate data.

For this reason, this transmitted data, that is, information specifying the sending and receiving terminals, signals indicating priority, signals for exclusive control of the line, data bit signals for transmission purposes, and band seek signals (an empty signal accompanying data exchange) etc.), and the data is sequentially transmitted in serial bits.By identifying the data in the data judgment circuit 11, the data judgment circuit 11 can identify, for example, the same data as positive logic bits the first time. To explain this using an example of an inverted two-sequence transmission verification method in which the second transmission is a reverse logical bit transmission,
When receiving, it is determined whether or not the data is correct by receiving and retaining the consecutive "two section length" data, reversing one of them, and comparing the two.As a result, if it is not regular data, An output is generated from the data judgment circuit 11,
The alarm signal transmitting circuit 14 is driven by the signal via the reception determination circuit 12, and the alarm signal is transmitted to the other station via the line 3 for a certain period of time regulated by the timer 13 activated by the alarm signal.

At the other station, when this alarm signal is received by the alarm signal receiving circuit 17 of the other station, the function of releasing the line from the occupied state is activated by the line occupation removal circuit 15 of the other station, and the other station is disconnected from the line 3. .

Further, when the alarm signal is transmitted after a certain period of time according to the time regulation of the timer 13, the alarm signal transmitting circuit 1
A new output is generated from line 4, and that output signal connects line 3.
The line occupancy removal circuit 15 is driven to release the occupancy state of the line occupancy removal circuit 15, and the occupancy/communication function circuit 16 stops its communication function due to the output from the line occupancy removal circuit 15. The terminal station's own occupation of line 3 is released and the use of line 3 is returned to an empty line, which is the same operation as described above when regular data is not transmitted from the other station for a certain period of time or more. It is something that does.

Hereinafter, when the line occupancy removal circuit 15 is driven, the display circuit 1 which is simultaneously displaying the occupancy state of the line 3 will be described.
B is also driven, and the occupied state display is erased.

On the other hand, if the terminal station is in a communication state and, for example, some kind of problem occurs in the circuit function and the transmission of regular data becomes impossible, the other station will not be able to receive the regular data for a certain period of time or more. Similarly to the above operations, an alarm signal is sent via the line 3 from the other station.

As a result, this alarm signal is received by the alarm signal receiving circuit 17 in the terminal station, and its output signal is applied as a driving input to the line occupation removal circuit 15.

As a result, the line occupation removal circuit 15 generates an output for canceling the line occupation state as described above, and the output signal causes the communication function of the occupation/communication function circuit 16 to be stopped.

Therefore, even if a terminal station causes a communication problem during data transmission, the terminal station will automatically be released from the occupied state of line 3 together with the other station by an alarm signal from the other station, and the line will become vacant. It will return to line condition.

Note that this line occupancy removal circuit 15 is driven, and at the same time, the display circuit 18 that has been displaying the occupancy state of the line 3 is also driven, and the display of the occupancy state is erased.

As described above, the present invention provides, in a data transmission system where a plurality of terminal stations share a line, the terminal stations: (1) means for determining whether or not human data is a legitimate data; (2) means for determining whether or not regular data is received within a certain time; (3) means for transmitting an alarm signal when no regular data is received; (4) said alarm signal. means for releasing the occupied state of the line by responding to the call or receiving an alarm signal transmitted from the other station; If the regular data is not received within the time, driving the alarm signal transmitting means by the output from the data determining means or the reception determining means;
The alarm signal transmitting means transmits an alarm signal for a certain period of time to the other station to notify the other station of the abnormal transmission state, and the alarm signal causes the other station to release the line occupation state, and also drives the line occupation removal means of the own station. On the other hand, the line occupancy removing means is separately driven in the same way by receiving an alarm signal transmitted from the other station, and the operation of the occupancy/communication function circuit is cut off by the output from the line occupancy removing means. This provides a data transmission device that can automatically remove not only the partner station or own station that has caused an abnormality, but also mutually occupied stations.

As a result, when the other station has a transmission error and normal data is not received for a certain period of time or input data is not normal data, the present invention sends an alarm signal to the other station for a certain period of time to notify the other station of the transmission abnormality. At the same time, such mutually occupied stations can be automatically removed from the line-occupied state, and - if the same occupied station causes an abnormality on Kodo, the same can be done by an alarm signal sent from the other station. The mutually occupied stations can be automatically removed from the line-occupied state, and the line can be returned to an idle line, which is a unique effect that cannot be obtained with conventional devices.

Therefore, the present invention also has the following effects: (1) line usage becomes more efficient, (2) abnormal stations are automatically removed, and (3) interference caused by abnormal stations is reduced. be.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention, and Fig. 1 shows the relationship between the transmission system between the central control station and each terminal station that shares the line, and Fig. 2 shows the detection, notification, and cancellation of transmission abnormalities. FIG. 2 is a block diagram of a terminal station equipped with means such as the above. In the drawing, 1 is the central control station, 2, 2', 2''...
・ is a terminal station, 3 is a line, 11 is a regular data judgment circuit, 1
2 is a circuit for determining whether normal data has been received for a certain period of time; 13 is a timer; 14 is an alarm signal transmitting circuit; 15 is a line occupancy removal circuit; 16 is an occupancy/communication function circuit; 17 is an alarm signal receiving circuit; 18 is a display circuit. It is.

Claims (1)

[Claims for Utility Model Registration] In a data transmission system in which a plurality of terminal stations share a line, data determining means for determining whether received input data is regular data; and the data determining means. reception determination means that follows the reception determination means and determines whether or not regular data is received within a certain period of time; An alarm signal transmitting means for transmitting an alarm signal for a certain period of time; and based on the alarm signal from the alarm signal transmitting means or the alarm signal transmitted from the partner station, the operation of the occupancy/communication function circuit is interrupted to prevent the line from being occupied. and an alarm signal receiving means configured to receive an alarm signal transmitted from the other station and drive the line occupation removal means, and when normal data is not input to the data determination means, or If the reception determining means does not receive regular data within a certain period of time, an output from the reception determining means activates an alarm signal transmitting means, and the alarm signal transmitting means transmits an alarm signal for a certain period of time and transmits it to the partner station. It notifies the abnormality, and uses the alarm signal to release the line occupation status of the other station, while driving the line occupation removal means of the own station, and interrupts the occupation/communication function circuit by the output from the line occupation removal means, thereby eliminating the transmission abnormality. 1. A data transmission device characterized in that the possessing authority associated with the above is automatically removed from line occupation.