JPH0936974A - Modem device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily handle connection with an opposite side data terminal to be connected with a modem device without requiring a cable. SOLUTION: When transmitting data, an infrared signal is received from the opposite side data terminal by a light receiver 8. When it is confirmed that a signal passing through an amplifier 9, a demodulator 10, and a serial controller 6, and arriving at a control circuit 2 is a transmitting command, a relay 18 is turned into connected state, the DC loop of a telephone line 19 is turned on and the signal is transmitted from a dialer 21. When a disconnecting command is received from the data terminal equipment or time-out is detected by a timer 5, communication is finished. Besides, when receiving data, a call signal is detected by an incoming call detection circuit, converted to an infrared signal through a modulator 11, drive circuit 12 and light emitter 13 while turning the relay 18 to the connected state and transmitted to the data terminal. When opposite side equipment finishes the transmission of data and a modem 15 detects carrier interruption, communication is finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modulator / demodulator for performing data communication using a telephone line.

[0002]

RS-232C is generally used as an interface between a conventional modulation / demodulation device and a data terminal device.
You need a thick cable with a 25-pin Dsub connector.

[0003]

However, in the above-mentioned conventional example, since the modem device and the data terminal device are connected by the thick cable, not only the cable occupies the space on the desk but also the modem device and the data terminal device. There is no freedom of storage space, and it is troublesome to insert and remove the cable when the data terminal device is moved or when a plurality of data terminal devices share a modulator / demodulator. Further, if the user forgets to connect the cable and operates both devices and notices that the cable is connected, there is a problem that the device may be broken.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a modulation / demodulation device that does not require a cable for connection with a data terminal device and is easy to handle.

[0005]

A modulation / demodulation device according to the present invention for achieving the above object is a modulation / demodulation device for performing data communication using a telephone line, and includes a line control section, a modulation / demodulation section, and an infrared communication section. The wireless communication is performed with the data terminal device of the other party by using infrared rays.

In this way, in the modulation / demodulation device that performs data communication using the telephone line, wireless communication is performed using infrared rays between the modulation / demodulation device and the data terminal device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a block circuit configuration diagram of an embodiment, in which a control unit 1 includes a control circuit 2 for controlling the entire modulation / demodulation device, a ROM 3 in which program instructions for the control circuit 2 to read are written in advance, and a control circuit 2 for data. A RAM 4 for writing and reading data, a timer 5 for the control circuit 2 to measure time, and a serial controller 6. The input / output of the serial controller 6 is connected to the infrared communication section 7 and serves as an interface between the control circuit 2 and the infrared communication section 7.

In the infrared communication section 7, the output of the photodetector 8 for receiving infrared rays and converting it into an electric signal is an amplifier 9 for amplifying the converted minute electric signal, and a predetermined signal suitable for the amplified infrared communication. It is connected to the serial controller 6 via a demodulator 10 that demodulates an electric signal that has been modulated into a format. Further, the output of the serial controller 6 is connected to a modulator 11 that modulates a data signal to be transmitted into a predetermined signal format suitable for infrared communication, and an electric signal modulated by a drive circuit 12 according to the output signal of the modulator 11 is output. Light source 13 that converts light into an optical signal and emits light
Is to be driven.

The input / output of the control unit 1 is the modulation / demodulation unit 1
4, the modulation / demodulation unit 14 includes a modulation / demodulation unit 15 and a parallel / serial converter 16. This modem 15
In order to perform data communication using a telephone line, a digital signal is modulated into an analog signal by, for example, a well-known phase modulation method, and the analog signal is demodulated into a digital signal. Further, the parallel / serial converter 16 converts the parallel data from the control circuit 2 into serial data and transmits the serial data to the modulator / demodulator 15, and converts the serial data, which is the demodulation output of the modulator / demodulator 15, into parallel data and controls the control circuit 2. It is designed to be read by.

Further, two lines / input / output of the modulator / demodulator 15 are used.
A relay 18 is connected through a four-wire converter 17, and the relay 18 is controlled to be turned on and off by the control circuit 2 to turn on and off a linear loop of the telephone line 19. Also, these 2-wire / 4-wire converters 1
7, relay 18, incoming call detection circuit 20, dialer 21
The circuit control unit 22 is composed of the control circuit 2 and the incoming call detection circuit 20 detects the call signal arriving from the telephone line 19 and detects the call signal.
The dialer 21 sends a dial pulse or a PB signal to the telephone line 19 according to an instruction from the control circuit 2.

FIG. 2 is a flow chart for transmitting and transmitting data. In step S1, an infrared signal from the data terminal device is received by the light receiver 8. In step S2, the light receiver 8, the amplifier 9, the demodulator 10,
When it is confirmed that the signal reaching the control circuit 2 via the serial controller 6 is not an erroneous signal but an outgoing command, the relay 18 is connected in step S3,
The DC loop of the telephone line 19 is turned on.

Then, in step S4, the telephone line 19
The telephone number included in the call command is transmitted from the dialer 21 as a dial pulse or a PB signal according to the type. In step S5, when the modulator / demodulator 15 detects the carrier and receives the notification, the control circuit 2 determines that the partner device has responded, and in step S6, the drive circuit 12 via the serial controller 6 and the modulator 11 causes the light emitter to emit light. 13 is driven and a response notification signal is transmitted to the data terminal device. If the modulator / demodulator 15 does not detect a carrier in step S5 and the signal received from the data terminal device in step S7 is not a disconnection command,
Returning to step S5, carrier detection is performed again.

In addition, when wireless communication by infrared rays between the modulation / demodulation device and the data terminal device is interrupted due to some cause and a signal cannot be received from the data terminal device,
In step S8, the timer 5 starts counting a predetermined time for the purpose of automatically ending the communication. In step S9, it is detected that the predetermined time has not passed, and in step S10, if a signal is received from the data terminal device via the infrared communication unit 7, step S11
At, the control circuit 2 stops the timer 5. If no signal is received from the data terminal device in step S10, the process returns to step S9 to detect whether or not a time-out has occurred.

Further, if the signal received from the data terminal device in step S12 is not a disconnection command, it is modulated into an analog signal by the modulator / demodulator 14 in step S13,
It is sent to the telephone line 19 via the circuit control unit 22. After transmitting, the process returns to step S8 again, and steps S8 to S13 are repeated.

If at step S9, the timer 5 notifies the time-out after a predetermined time elapses,
If the signal received from the data terminal device is a disconnection command in S7 and S12, the control circuit 2 proceeds to step S1.
At 4, the relay 18 is disconnected, the DC loop of the telephone line 19 is turned off, and the communication ends.

FIG. 3 is a flow chart for the case where an incoming call is received from the partner device and data is received. In step S21, the ringing signal from the telephone line 19 is detected by the incoming call detection circuit 20.
When it is detected by the control circuit 2, the control circuit 2 transmits a signal for notifying the incoming call to the data terminal device via the infrared communication section 7 in step S22.

When a response command is received from the data terminal device through the infrared communication section 7 in step S23, the relay 18 is connected in step S24, the DC loop of the telephone line 19 is turned on, and the step S2
At 5, the carrier signal is transmitted from the modulator / demodulator 15 to the telephone line 19 via the circuit controller 22. In addition, before receiving the response command from the data terminal device, step S26
When it is detected that the calling signal is stopped in step S27, a signal for canceling the incoming call notification is transmitted in step S27, and if the calling signal is not stopped, the process returns to step S22.

When the response command is received, the response signal is modulated by the modulator / demodulator 15 and transmitted to the telephone line 19 in step S28. The signal transmitted from the telephone line 19 is demodulated by the modulator / demodulator 15 in step S29, and the parallel / serial converter 16, the control circuit 2, the serial controller 6, and the modulator 1 in step S30.
1, converted into an infrared signal through the drive circuit 12 and the light emitter 13 and transmitted to the data terminal device.

In step S31, if the carrier disconnection is not detected, the process returns to step S29. However, since the partner device has finished transmitting data and disconnected the line, the modem 15
When the carrier disconnection from the telephone line 19 is detected, the disconnection notification signal is transmitted from the control circuit 2 to the data terminal device in step S32. Further, in step S33, the control circuit 2 disconnects the relay 18, disconnects the DC loop of the telephone line 19, and terminates the communication.

[0020]

As described above, the modulation / demodulation apparatus according to the present invention uses infrared rays between the modulation / demodulation apparatus and the partner data terminal apparatus to communicate with in the modulation / demodulation apparatus for performing data communication using the telephone line. Since wireless communication is performed, a thick cable is not required to connect the modulation / demodulation equipment to the data terminal equipment, and the cable does not occupy the space on the desk. The movement of the device is also very easy, and even when a plurality of data terminal devices share a modulator / demodulator, it is possible to make the configuration easy to handle without the need to insert and remove the cable.

[Brief description of drawings]

FIG. 1 is a block circuit configuration diagram of an embodiment.

FIG. 2 is a flow chart diagram when transmitting and transmitting data.

FIG. 3 is a flowchart of a case where an incoming call is received from a partner device and data is received.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 control part 2 control circuit 5 timer 6 serial controller 7 infrared communication part 8 light receiver 9 amplifier 10 demodulator 11 modulator 12 drive circuit 13 light emitter 14 modulator / demodulator 15 modulator / demodulator 16 parallel / serial converter 17 2 wire / 4 wire Converter 18 Relay 19 Telephone line 20 Incoming call detection circuit 21 Dialer 22 Circuit control unit

Claims (3)

[Claims] 1. A modulation / demodulation device for performing data communication using a telephone line, comprising a line control unit, a modulation / demodulation unit, and an infrared communication unit, and performing wireless communication using infrared rays with a data terminal device on the other side. A modulator / demodulator characterized by. 2. The infrared communication unit includes a modulator that modulates a data signal into a predetermined signal format suitable for wireless communication using infrared light, and a light emitter that converts the signal modulated by the modulator into infrared light. A driving circuit for driving the light emitter according to the signal, a light receiver for receiving infrared rays and converting it into an electric signal, an amplifier for amplifying the electric signal to a level sufficient for demodulation by a demodulator, and wireless communication by infrared rays A demodulator for demodulating a received signal modulated into a signal format suitable for the above into a data signal. 3. When a signal is no longer received from the data terminal device after transmitting a command from the data terminal device to detect a response from the data terminal device on the other side, the timekeeping means measures the time, The modulation / demodulation device according to claim 1, wherein the line is disconnected when no signal is received from the terminal device for a predetermined time.