JPH04257157A - Data communication device utilizing telephone line - Google Patents

Abstract

PURPOSE:To give the use of a telephone set priority to a data communication on the data communication device which uses one telephone line in common to the telephone set. CONSTITUTION:A CPU which performs control operation according to a program is included as a control part and a data transmission and reception part 9 equipped with a modem is connected to the CPU through a serial I/O interface. The control part calls a transmission destination unless a call signal detecting circuit 22 detects a call signal and an off-hook detecting circuit 21 detects an off-hook state, and contacts S1 and S2 are connected by the calling to input and output data through the data transmission and reception part 9. If the off-hook detecting circuit 21 detects the off-hook state during the input and output of the data, the contacts S1 and S2 are broken and then the contact S1 is connected a specific time later.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for communicating data using a telephone line.

0002

2. Description of the Related Art As a device for communicating data using a telephone line, for example, there is a prior art in the field of vending machines as disclosed in Japanese Patent Application Laid-open No. 301377/1983. In this prior art, the data transmitting/receiving device is paired with a telephone that has the same telephone number as the data transmitting/receiving device, and communicates with the other party via a telephone line common to the telephone, and the data transmitting/receiving device presses a start communication button. This system calls the other party and sends data based on the operation of the other party or at a time previously specified by the other party.

0003

The configuration of the prior art described above has the advantage that the telephone line used for the telephone is also used for data communication, so that the telephone line can be used effectively.

However, a drawback of the prior art is that the telephone cannot be used while data is being transmitted. In particular, if a plurality of such data transmitting/receiving devices are provided and data is sequentially transmitted from each data transmitting/receiving device over a single telephone line, there is a problem that the telephone cannot be used for a long time.

[0005] Accordingly, an object of the present invention is to give priority to the use of the telephone over data transmission and reception in a data communication device in which a single telephone line is used in combination with a telephone.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, a data communication device using a telephone line according to the present invention transmits and receives data through a telephone line connected to a telephone. A line connection terminal connected to a line, a ring signal detection circuit for detecting a ring signal transmitted through the line connection terminal, and a ring signal detection circuit provided between the line connection terminal and the telephone to detect an off-hook state of the telephone. a first disconnection device that disconnects the off-hook detection circuit from the telephone; a data transmitting/receiving unit connected to the connection point between the line connection terminal and the off-hook detection circuit; and the connection point. and a second cutoff device that cuts off the connection with the data transmitting unit, and a control unit that controls the outgoing call to the other party and the input/output of transmitted and received data, and the control unit is configured such that the calling signal detection circuit means for calling a destination when a calling signal is not detected and an off-hook detection circuit does not detect an off-hook state; and a means for placing both the first cutoff device and the second cutoff device in a connected state by the calling. data input/output means for inputting and outputting data through the data transmitting/receiving section; and when the off-hook detection circuit detects an off-hook state during input/output of data, both the first cutoff device and the second cutoff device are set to a disconnected state. and a call priority control means for setting the first cutoff device to a connected state after a predetermined period of time has elapsed.

[0007]

[Operation] When entering the data communication mode, the control unit first calls the destination on the condition that the paging signal detection circuit does not detect a paging signal and the off-hook detection circuit does not detect an off-hook state. do. Then, the control section connects both the first cutoff device and the second cutoff device, and inputs and outputs data through the data transmission/reception section. When the off-hook detection circuit detects an off-hook state during the input/output of this data, the control unit disconnects both the first disconnection device and the second disconnection device to open the communication line, and after a predetermined period of time has elapsed, the controller 1. The telephone can be used by setting the disconnection device to the connected state. This gives priority to telephone calls over data transmission and reception.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a circuit configuration of a data communication apparatus using a telephone line according to this embodiment, and includes a CPU 1 as a control section which executes control operations according to a program. The CPU 1 is connected via an address bus 5 and a data bus 6 to a ROM 2 that stores operating programs, a RAM 3, and a clock circuit 4. RAM3 and clock circuit 4
is backed up by a battery backup circuit 11 to prevent data from being erased in the event of an unexpected power outage.

Serial I/O interfaces (SIO) 7 and 8 are connected to the data bus 6. SIO7
A data transmitter/receiver 9 is connected to the SIO 7 , and the SIO 7 converts parallel data outputted from the CPU 1 through the data bus 6 into serial data and outputs the serial data to the data transmitter/receiver 9 . The data transmitting/receiving section 9 includes a modem, modulates the given serial data into an analog signal compliant with the communication method, and sends it to the network control unit (NCU).
Output to 10. This NCU 10 has connection terminals 23,
A telephone line 14 and a telephone set 15 are connected through 24, respectively.

[0010] The CPU 1 further includes a non-volatile rewritable memory 1 for storing the telephone number of the data communication destination.
2 and a switching setting device 13 are connected. The switch setting device 13 determines whether the telephone line to be used is a push button line (PB
) or dial line (DP), and in the case of DP, the communication speed is set to 10 pps or 20 pps.

As shown in FIG. 2, the NCU 10 includes a line transformer 20, an off-hook detection circuit 21, a calling signal detection circuit 22, and a relay R1 whose energization is controlled by the CPU 1.
, R2, and one side of the line transformer 20 provided for insulation is connected to the data transmitting/receiving section 9, and the other side is connected to the telephone line 14 via the contact S2. . A series circuit of the off-hook detection circuit 21 and the contact S2 is connected to the telephone line 14 so as to be parallel to the contact S2, and a telephone 15 is connected to the contact S1. Relay R1 and contact S1 serve as a disconnection device that cuts off the connection between off-hook detection circuit 21 and telephone 15, and relay R2 and contact S2 serve as a connection point 26 between line connection terminal 23 and off-hook detection circuit 21 and data transmitting/receiving section 9.
This serves as a second disconnection device that disconnects the connection.

The off-hook detection circuit 21 detects off-hook of the telephone 15 by detecting the DC loop current while the contact S1 is closing the circuit, and outputs an off-hook detection signal LP to the CPU 1 when off-hook is detected. Further, a ringing signal detection circuit 22 connected to a connection terminal 23 in parallel with the contact S2 and the off-hook detection circuit 21 detects the presence or absence of a ringing signal sent through the telephone line 14, and generates a ringing detection signal by detecting the ringing signal. CI to CPU1
Output to.

A communication interface 16 is further connected to the CPU 1. A device 30 that transmits and receives data using this communication device is connected to the communication interface 16, and the CPU 1 calls a data communication destination according to commands from this device 30, and receives transmission data sent from the device. It transmits the data to the communication destination and transfers the data received from the communication destination to the device 30. Also, CPU1
By connecting the switch 17 and the sensor 18 to the terminal, data from these can also be transmitted. in this case,
The CPU 1 stores the data of the switch 17 and the data of the sensor 18 in the RAM 3, and when the time indicated by the clock circuit 4 reaches a preset time, the CPU 1 enters a calling state and stores these data stored in the RAM 3. Send. Further, a general-purpose input/output terminal 29 is connected to the SIO 8, and data input from this input/output terminal 29 is transmitted from the telephone line 14, and data received from the telephone line 14 is output from the input/output terminal 29. be able to.

In the above configuration, when the data communication device attempts to make a call, the CPU 1 checks whether it is in a standby state. First, the CPU 1 detects the presence or absence of the call detection signal CI to confirm whether a call to the telephone 15 is occurring. Next, the CPU 1 detects the off-hook detection signal LP to confirm that the telephone 15 is off-hook and is in a call. At this time, the CPU 1 controls the relays R1 and R2 so that the contact S1 is in a closed state and the contact S2 is in an open state. Then, the CPU 1 enables calling when the calling signal detection circuit 22 does not detect the calling signal CI and the off-hook detection circuit 21 does not detect off-hook.

The procedure for making a call by the CPU 1 is as follows:
4 is a PB line, the relay R2 is controlled so that the contact S2 is closed, and the data corresponding to the telephone number of the transmission destination stored in the memory 12 is sent to the SIO 7. The data is then converted into a serial signal and introduced into the data transmitting/receiving section 9, which modulates it into an analog signal and outputting it to the NCU 10 as a DTMF signal. The NCU 10 outputs this DTMF signal to the telephone line 14, thereby making a call to the data communication destination.

Further, when the telephone line 14 is a DP line, the CPU 1 controls the relay R2 so that the contact S2 is opened, and also controls the contact S to open the contact S2 according to the telephone number of the destination party.
The relay R2 is controlled so that the relay R2 opens and closes. That is, the CPU
1 is relay R for the number of times according to the number of each digit of the phone number
By repeating the energization/de-energization control in step 2, a dial signal is output to the telephone line 14. After the dialing is completed, the CPU 1 controls the relay R1 so that the contact S1, which was kept open to prevent the telephone 15 from ringing due to the dialing, is closed.

[0017] For data transmission, the transmission data stored in the RAM 3 is sent to the SIO 7, the data transmitting/receiving unit 9, and the NCU 10.
This is done by outputting to the telephone line 14 through the Furthermore, data transmitted from the other party is introduced to the CPU 1 through a route opposite to this. When the telephone 15 goes off-hook during data communication, an off-hook detection signal LP is input to the CPU 1 from the off-hook detection circuit 21 . CPU
1 is by controlling relays R1 and R2 so that both contacts S1 and S2 are in an open state in response to an off-hook detection signal LP, and then controlling relay R1 so that only contact S1 is closed after a certain period of time has elapsed. , the line on which data is being transmitted is released and the telephone 15 can be used.

When the data communication is completed, the CPU 1 opens both the contacts S1 and S2, and after a certain period of time, controls the relays R1 and R2 so that only the contact S1 is closed. This is to ensure that a call termination signal is generated.

A plurality of the above data communication devices can be connected to one telephone line. The data communication device is shown in FIG. 3, and includes an input terminal 25 into which a communicating signal from the preceding data communication device is input, and an output terminal 26 which outputs the communicating signal to the subsequent data communication device. The data communication devices C1 to Cn are connected in this manner. A telephone line 14 is connected to the data communication device C1 at the top, and a telephone 15 is connected to the data communication device Cn at the bottom. Each data communication device is connected to a terminal 23 connected to a telephone line of the communication device.

[0020] Even when a plurality of data communication devices are connected in this way, not only can calls be made from any data communication device, but the priority function of the telephone 15 does not change. Therefore, a certain data communication device may detect off-hook detection circuit 21.
When the telephone 15 confirms that it is not off-hook and enters the communication state, the CPU 1 of this data communication device
In order to output a communicating signal to the data communication device in the subsequent stage, all data communication devices in the subsequent stage are prohibited from making calls. At this time, in a data communication device connected to a higher level than this data communication device, the off-hook detection circuit 21 of this higher level data communication device is off-hook by the closed circuit of the contact S2 of the subsequent data communication device and the line transformer 20. Since this is detected, the higher-level data communication device also does not make a call.

The present invention allows calls to be made from the data communication device on the terminal side, but it is of course also possible to make calls from the center side using non-ringing communication. In this case, in the circuit of the embodiment, as shown in FIG. By connecting, it is possible to support the non-ringing communication service.

[0022]

[Effects of the Invention] According to the present invention, even if data communication is being performed, priority can be given to calls made by telephones connected to the same telephone line, so that the telephone line to which the telephone is connected can be used. be.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a data communication device.

[Figure 2] Network control unit (NCU)
FIG. 2 is a block diagram showing the configuration of FIG.

FIG. 3 is a diagram showing an embodiment in which a plurality of data communication devices are provided.

FIG. 4 is an embodiment corresponding to no-ringing communication.

[Explanation of symbols]

1 Control section 9 Data transmission/reception section 14　Telephone line 21 Off-hook detection circuit 22 Calling signal detection circuit 23 Line connection terminal

Claims (1)

[Claims] Claim 1: In a data communication device using a telephone line that transmits and receives data through a telephone line connected to a telephone, detecting a line connection terminal connected to the telephone line and a calling signal transmitted through the line connection terminal. an off-hook detection circuit provided between the line connection terminal and the telephone to detect an off-hook state of the telephone; and a first disconnection device for interrupting the connection between the off-hook detection circuit and the telephone. a data transmission/reception unit connected to a connection point between the line connection terminal and the off-hook detection circuit; a second disconnection device that disconnects the connection point from the data transmission unit; and a control unit that controls the input/output of transmitted and received data, and the control unit is configured to transmit data when the ringing signal detection circuit does not detect a ringing signal and the off-hook detection circuit does not detect an off-hook state. means for making a call to the destination; data input/output means for inputting and outputting data through the data transmitting/receiving section by connecting the first cutoff device and the second cutoff device when the call is made; and call priority control means for setting both the first cutoff device and the second cutoff device in a disconnected state when the off-hook detection circuit detects an off-hook state, and then setting the first cutoff device in a connected state after a predetermined period of time has elapsed. A data transmission device using a telephone line, characterized in that: