JPH0330346B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a terminal-originating type transmission device in which data is transmitted only in one direction from a terminal device to a center device using a telephone line.

[Technical background of the invention]

Conventionally, when transmitting data from a terminal device to a center device, the terminal device has applied parity bits and block checks to the data as shown in JIS-C6360 in order to ensure the reliability of data transmission at the center device. On the other hand, the center device performs a data check on the received data according to the transmission procedure shown in JIS-C6362, and if a transmission error is detected, sends a retransmission request to the terminal device. control to ensure accurate data transmission.

By the way, there are devices that transmit data through telephone lines, and in this case, it is not practical to install a telephone line exclusively for transmission on the terminal side, so it is necessary to use a general subscriber telephone line to switch between calls and data transmission. It is efficient to do so. However, in order to switch between calls and data transmission, it is not possible to automatically receive calls because it is difficult to distinguish between normal calls and data transmission when a call is received, and an automatic dialing method from the terminal device must be adopted. I can't do it. In this way, since the center device cannot request data transmission to the terminal device, it is an absolute requirement to receive data reliably.

Additionally, a common method used to ensure the reliability of data transmission is the terminal transmission method, in which the data receiving side determines the validity of the data and sends a response back to the data transmitting side. On the other hand, on the data transmitting side, the response sent back to the data transmitter is checked to determine whether the data has been transmitted correctly, and if necessary, the data is retransmitted to ensure data transmission.

FIG. 5 is a block diagram of a conventional terminal originating transmission device that employs the terminal originating method. The terminal device 1 is connected to a center device 4 via a telephone line 2 and an exchange 3, and data transmission is performed as shown in the operation timing chart shown in FIG. Note that in FIG. 6, A indicates the operation of the terminal device 1, and B indicates the operation of the center device 4.
shows the operation. That is, as shown in FIG. 5, at time t1 when data is to be transmitted, first, the control section 5 in the terminal device
is switched from the telephone 7 to the terminal device 1 side, and the closing portion 8 is closed. As a result, a 400Hz dial tone (dial tone DT) H from the exchange 3 is received from the coupling section 9 through the interface 10 to the dial tone detection section 11, and upon confirmation of this dial tone, the control section 5 A selection signal (dial signal) D is sent from the terminal. This dial signal D is sent from the telephone line 2 to the exchange 3, and from this exchange 3 is sent as a calling signal (ringing tone) Y to the center device 4. When this calling signal Y is input to the center device 4, detected by the calling signal detection section 13, and the detection signal is issued to the control section 14, at this time t2, the control section 14 closes the closing section 15 and enters the incoming state. do. After entering this state, the terminal device 1 transmits data DT1 from the transmitter 12. This data DT1 is transmitted to the center device 4 via the telephone line 2 and the exchange 3. The signal is then received by the receiving section 18 through the coupler 16 and interface 17 of the center device 4 . The control unit 14 determines whether the received data DT1 is normal or not. Here, if an abnormality is detected, the control section 14 causes the transmission section 19 to send out a negative response signal G1. This negative response signal G1 is sent to the terminal device 1 through the telephone line 2 and the exchange 3, and is sent to the receiving section 20.
received at Then, the control unit 5 re-enters the data.
Data DT2 having the same content as DT1 is sent out from the transmitter 12. When this data DT2 is also detected to be abnormal by the center device 4, a negative response signal G2 is sent out again and transmitted to the terminal device 1. Then, data DT3 having the same content as data DT1 is sent again to the center device 4, and if the data is determined to be normal, an acknowledgment signal K is sent. Then, when this acknowledgment signal K is received by the terminal device 1, a termination signal S is sent to the center device 4, and the closing portion 8 is opened by the control portion 5, and the switching portion 6 is switched to the telephone side. Switched. In addition, in the center device 4, the closing portion 15 is opened upon reception of the termination signal S.

[Problems with background technology]

However, in the above device, the data transmission direction is only one direction from the terminal device 1 to the center device 4, but a transmitter 19 and a receiver 20 must be provided to send a response signal indicating whether the data is normal. No. Therefore, the price of the device increases accordingly. Therefore, in order to avoid increasing the price of the device, the transmitting section 19 and receiving section 20 for sending out a response signal indicating whether the data is normal are eliminated.
There is a method that repeatedly sends the same data multiple times. However, with this method, even if the same data is sent multiple times, there is no guarantee that the data will be sent accurately, and the data transmission time will only increase. , which is a fatal flaw.

[Purpose of the invention]

The present invention was made based on the above circumstances, and
The purpose is to provide a highly reliable terminal-originated transmission device that can reliably transmit data without sending a response signal indicating whether the data is normal.

[Summary of the Invention] In order to achieve the above object, the present invention connects a terminal device and a center device via a telephone line, and the data transmission direction is only one direction from the terminal device to the center device. In a terminal-based transmission device, even if a predetermined period of time has elapsed after transmitting data,
The terminal device is equipped with a functional means that retransmits data if it does not receive a busy tone due to the release of the telephone line of the center device, and also receives data from the terminal device in response to a paging signal, and transmits the data. The center device is equipped with a functional means that releases the telephone line if the telephone line is normal, and maintains the telephone line connection state and waits for data to be re-received if the telephone line is abnormal.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a terminal originating type transmission device.
The terminal device 30 is connected to a center device 50 via a telephone line 40 and an exchange 41. Although a plurality of terminal devices 30 are connected to the center device 50, only one terminal device is connected here. In particular, if the data transmitter does not receive a dial tone, that is, a busy tone BT sent from the exchange to the calling subscriber's line when the called party makes a pre-order call, the terminal device 30 transmits the message again after a predetermined period of time has elapsed. It has the function of sending out data with the same content. Specifically, a switching unit 31 is connected to the telephone line 40 , and the switching unit 31 is configured to switch the terminal device 30 and the telephone 32 to the telephone line 40 . One end of a coupling section 34 is connected to this switching section 31 via a closing section 33, and an interface 35 is connected to the other end of this coupler 34. Data is exchanged between the telephone line 40 and the transmitting section 36 and the transmitting section 37 . Now, the control unit 38 controls data transmission according to the program of the data transmission flowchart shown in FIG. ) is not received by the dial tone detection section 36, the function is to transmit data with the same content again.

On the other hand, the center device 50 receives the data after receiving the call signal from the exchange 41, judges whether the data is normal or not, and releases the connection with the telephone line 40 if the data is normal, or if there is an abnormality. If there is one, it has a function of continuing the connection with the telephone line 40 and making it possible to re-receive data. Specifically, one end of a coupler 52 is connected to the telephone line 40 via a switching section 51, and the other end of this coupler 52 is connected to an interface 53. The receiving section 54 receives data through this interface 53. In addition, the switching section 51
A calling signal detection section 55 is provided on the telephone line 40 side of the telephone line 40 to detect a calling signal and send the detection signal to a control section 56. Now, this control section 56 controls data reception according to the program of the data reception flowchart shown in FIG.
After receiving the call signal from 1, the data is received,
It is determined whether this data is normal or not, and if it is normal, the connection with the telephone line 40 is released, and if there is an abnormality, the connection with the telephone line 40 is continued and the data is re-received. It is something that has a function.

Next, the operation of the apparatus configured as described above will be explained with reference to the data transmission flowchart shown in FIG. 2, the data reception flowchart shown in FIG. 3, and the operation timing chart shown in FIG. 4. Note that in FIG. 4, Aa indicates the operation of the terminal device 30, and Ba indicates the operation of the center device 50.

When a data transmission request occurs at time t10, the control section 38 of the terminal device 30 switches the switching section 31 from the telephone 32 to the terminal device 30 side at step e1, and the closing section 33 is closed at step e2. As a result, in step e3, a dial tone (dial tone) is emitted from the exchange 32.
DT) is received by the dial tone detection section 36 from the coupler 34 through the interface 35, and upon confirmation of this dial tone (dial tone DT), the control section 38 transmits the selection signal ((DT)) from the transmitting section 37 in step e4. Dial signal) D is sent. This dial signal D is sent from the telephone line 40 to the exchange 41, and from this exchange 41 is sent to the center device 50 as a calling signal (ring back tone RBT) Ya.

On the other hand, the center device 50 is in the detection state of the calling device Ya, and the calling signal Ya is transmitted to the center device 50.
When the signal is input, the calling signal detecting section 55 detects this and outputs the detection signal to the controlling section 56. As a result, in step f1, the control section 56
closes the closing part 51 to receive a call (time
t11).

Here, the control unit 38 of the terminal device 30
At e5, it is determined whether the center device 50 is in the incoming call state, and at time t11, when it is determined that the center device 50 is in the incoming call state, data is transmitted from this point onwards. Note that if the center device 50 does not receive a call for a predetermined period of time in step e6, it is determined that the time has elapsed and the process ends in error.

Now, if the call is received, the terminal device 30
is the data sent from the transmitter 37 in step e7.
Send DTa. This data DTa is telephone line 4
0, is transmitted to the center device 50 via the exchange 41. The signal is then received by the receiving section 54 through the coupler 52 and interface 53 of the center device 50 (step f2). By the way, when the data DTa is thus received at step f2, it can be determined whether the data DTa is normal at the next step f3. Here, if it is determined that there is an abnormality, the process moves to step f4 to keep the retransmission data receiving state, that is, the closing section 51 continues to be in the closed state.

On the other hand, after sending the data DTa, the terminal device 30
Move to step e8, dial tone (busy tone BT)
It is in the detection state of Ha′. Therefore, since the center device 50 continues to be connected to the telephone line 40 at this time, the dial tone Ha' does not arrive. Therefore, the beep Ha′ is not received for the predetermined period of time, that is, step e9
In step e7, it is determined that the time has elapsed, and the process returns to step e7, where data DTb having the same content as data DTa is retransmitted. The center device 50 receives this data DTb and determines whether or not the data DTb is normal in step f3 in the same manner as described above. If it is determined to be abnormal again, the center device 50
1 remains closed. Therefore, the terminal device 30 returns to step e7 and sends out data DTc having the same content as data DTa.

Now, if this data DTc is received by the center device 50 and determined to be normal as determined in step f3, the closing portion 51 is opened by the control portion 56 in step f5. This allows telephone line 4
0 is released, and a dial tone (busy tone BT) Ha' is sent from the exchange 41 to the terminal device 30 and the center device 50. Thus, the terminal device 30 emits a dial tone (busy tone) in step e8.
BT) Ha′ is received, so the next step e10,
Move to e11, open the closing part 33, then switch part 31
switch to the telephone 32 side. This means that the data has been accurately transmitted. In addition,
If data is transmitted several times and all of them are determined to be abnormal, the process moves to step e12 and ends with an error.
Also, when the center device 50 is in the data reception state (step f2), step f6
If no data is received for a predetermined period of time based on the judgment, the closing section 51 is opened and an error termination occurs.

In this way, in the above embodiment, when data is transmitted from the terminal device 30, the center device 50
If the received data is normal, the telephone line 40 is released, and if it is abnormal, the telephone line 40 is closed and the data is re-received.On the other hand, the terminal device 30 closes the telephone line 40 of the center device 50 after sending the data. If the release tone (busy tone BT) Ha' is not received, the data is retransmitted, so even if the data transmission direction is only one direction from the terminal device 30 to the center device 50, it is determined whether the data is normal or not. There is no need for any response signal transmitting/receiving section, and data can be transmitted reliably and accurately using only the telephone line 40 and its connection means necessary for telephone calls. As a result, there is no need to provide a receiving section on the data transmitting side and a transmitting section on the data receiving side, contributing to the simplification and cost reduction of the device. Moreover, the center device 50 can also determine whether the data is normal or not, and can repeat transmission until the data is transmitted normally. Therefore, the time required for data transmission can also be reduced. Furthermore, if the data is not transmitted even after a predetermined period of time has elapsed, or if the data is determined to be abnormal even after several transmissions, an error display can be displayed, and the abnormality can be immediately notified.

It should be noted that the present invention is not limited to the above embodiment, and can be modified without departing from the spirit thereof. For example, the format of the data to be transmitted may be a frequency modulation signal FSK, a multifrequency mixed signal DTMF, or the like. Further, the dial signal is transmitted to the closing part 33
A dial pulse may be generated by opening and closing the dial, or a PB dial tone may be generated by the transmitter 37.

〔Effect of the invention〕

As explained above, according to the present invention, accurate data transmission can be performed reliably without sending a response signal indicating whether the data is normal. It is possible to provide an extremely reliable terminal transmission type transmission device that does not require a transmitter and can contribute to the simplification and cost reduction of the device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a terminal origination type transmission device according to the present invention, FIG. 2 is a data transmission flowchart of the device of the present invention, FIG. 3 is a data reception flowchart of the device of the present invention, and FIG. The figure is an operation timing diagram of the device of the present invention, FIG. 5 is a configuration diagram of the conventional device, and FIG. 6 is an operation timing diagram of the conventional device. 30...Terminal device, 31...Switching unit, 33...
Closing unit, 35...Interface, 36...Tone detection unit, 37...Transmission unit, 38...Control unit,
40... Telephone line, 41... Exchange, 50... Center device, 51... Closing section, 53... Interface, 54... Receiving section, 55... Calling signal detection section, 56... Control section.

Claims (1)

[Scope of Claims] 1. In a terminal-originating type transmission device in which a terminal device and a center device are connected via a telephone line, and the data transmission direction is only one direction from the terminal device to the center device, The terminal device is provided with a functional means for retransmitting the data if a busy tone due to the release of the telephone line of the center device is not received even after a predetermined period of time has elapsed since the data was transmitted; functional means for receiving data from the terminal device in response to the received data, and if the data is normal, the telephone line is released; if the data is abnormal, the telephone line is maintained in a connected state to wait for re-reception of the data; A terminal transmission type transmission device, characterized in that the center device is equipped with the following.