JPH05191525A - Data/sound switching device - Google Patents

Abstract

PURPOSE:To discriminate carrier signals even if they have the same analog wave by synthesizing the tone signals of different frequencies with two signals, identifying them, judging a present output signal and transmitting it by means of exclusive selection. CONSTITUTION:A tone signal 11 and the data string 12 of binary code string expression are inputted to mixers 13 and 14. On the other hand, tone generators 15 and 16 generate the tone signals A and B and they are inputted to the mixers 13 and 14. The mixer 13 synthesizes the signal with the signal A, and the mixer 14 synthesizes the signal 12 with the signal B. Since the mixer 14 synthesizes the analog wave, it is once converted into an analog data signal in modem 17 and is inputted to the mixer 14. An AFSK system is adopted for the conversion processing of MODEM 17, and an error rate is reduced. The outputs of the mixers 13 and 14 are connected to the contact points (a) and (b) in a switch 18, and a midpoint (c) is connected to the output of a telephone line, whereby the switching is executed by a control signal 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when transmitting binary coded data in addition to a normal voice signal by using an analog telephone line, automatically distinguishes the two from each other and connects to the telephone line. The present invention relates to a switching device for outputting or appropriately connecting a signal input from a telephone line to each line.

[0002]

2. Description of the Related Art Recently, a technique of transmitting binary coded data using a telephone line has been widely used. Examples of this technique include a facsimile and an acoustic coupler.

Among these, in the facsimile with a telephone function, when the telephone function and the image transmission function are switched on the transmitting side, if the micro switch detects the communication sheet inserted in a fixed position, the facsimile function is selected and the communication sheet is fixed. The telephone function is selected by picking up the handset without inserting it into the position. Also, the receiving side can perform automatic reception, but as its configuration, it outputs a standby signal for a certain period of time when it receives a calling signal, and if it does not receive an image signal converted into a bit image during that time, it has a telephone function. It is common to switch to.

On the other hand, the acoustic coupler is constructed such that a digital signal of a computer is once converted into a signal in an audible range which can be handled by a telephone line and then output, or the signal is converted into a digital signal. In any case, the switching is manually performed by the user.

[0005]

In the above-described structure, both a voice signal and a data signal can be sent by one telephone line, but the transmission side must manually switch the connection. In addition, the automatic reception configuration on the receiving side is a deeming process based on delay processing in which either voice reception or data reception is set to the priority reception state and switching is first performed when the signal is not received within a certain time. It is not the one that discriminates itself and switches.

By the way, recently, not only facsimile but also data communication has become widespread, and various kinds of binary coded data are targeted for transmission. In particular, personal computers are now widely used for personal computer communication. In this configuration, the output of the computer is connected to a modem, where it is converted into an analog signal and transmitted using a telephone line. However, there is a disadvantage that a dedicated line must be drawn and a separate line must be used for a voice signal unless a configuration such as the above-mentioned automatic reception of a facsimile is used.

The present invention is intended to solve these problems in the related art, and outputs a voice signal and a data signal exclusively to one telephone line, and at the same time promptly determines which signal the input side is. It is an object of the present invention to provide a data / voice switching device that can be judged and input to each device.

[0008]

In the present invention, in order to achieve the above-mentioned object, a means for synthesizing a tone signal with an analog voice signal and a means for converting a digital data string into an analog data signal and then changing the frequency of different frequencies are used. A switching device for transmission which has both means for synthesizing tone signals, judges the exclusively inputted voice signal and data signal, and transmits one of them to the telephone line, and the telephone line. The received signal from another device received via the above is input to the frequency determiner via the two band filters corresponding to the two tone signals, and is input to the two notch filters corresponding to the two tone signals. , A means for providing in parallel a switching device for reception that outputs the notch filter on the side that matches the tone signal determined by the frequency determiner.

[0009]

The voice signal and the data string are exclusively inputted to the switching device for transmission of this device. Then, the tone signals of the respective predetermined frequencies are combined, and this has the effect of generating a signal containing a pilot signal for identifying which signal. Further, the judging device has a function of judging which signal is currently being processed, and thereby operates to switch the signal outputted to the telephone line.

On the other hand, the receiving side has a function of discriminating which signal is received from one telephone line. The frequency of the tone signal is taken out by a band filter, and this is sent to a frequency judging device. Input and select the higher level frequency component. Then, the received signal removes the tone signal component through a notch filter paired with the band filter, but selects the notch filter output on the side that matches the band filter on the selected side, or the telephone at the latter stage, or It acts to output to a computer or the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. First, the installation outline of the device of the present invention is shown in FIG. 1. NW is an existing telephone line network, A1 to An are data / voice switching devices of the present invention, which are connected to the telephone line network NW by an up line and a down line. ing. Each switching device A1 to An is composed of a switching block 1 for transmission and a switching block 2 for reception. Further, a telephone and a computer are connected in parallel to the data / voice switching device A (not shown) to input / output a data string and an analog signal to / from the device.

Next, FIG. 2 shows data / voice switching devices A1 to A1.
It is a block diagram showing an internal configuration of each An. On the transmission side, 11 is a voice signal and 12 is a data string represented by a binary code string, which are input to mixers 13 and 14, respectively. The mixers 13 and 14 have tone generators 15 for generating tone signals A or B having different frequencies.
16 is connected, and the mixer 13 combines the voice signal and the tone signal A, and the mixer 14 combines the data signal and the tone signal B. The tone signal A functions as a voice signal identification signal, and the tone signal B functions as a data identification signal, that is, as a pilot signal, and is set to a frequency near the upper limit of the carrier band of the telephone line. . This is intended to prevent the signal from being adversely affected by utilizing the lowest possible portion of the spectral distribution of the audio signal. Since the mixer 14 that handles the data string 12 synthesizes analog waves, it is once converted into an analog data signal by the modem 17 and then input to the mixer 14. The conversion process by the modem 17 is based on the AFSK method (AUDIO FREQUENCY SHIFT KEYING), which reduces the error rate. The outputs of the mixers 13 and 14 are connected to the a contact and the b contact of the switch 18, respectively, and the midpoint c is connected to the telephone line output. The midpoint c is switched by the control signal 19. . The control signal 19 is output from the data / speech judging unit 20, and distinguishes between the analog sound signal input to the judging unit 20 and the character of the digital data string, and switches the switch 18 accordingly. There may be a plurality of methods for switching the switch 18, for example, the switch 18
Is normally a contact (usually, the a contact and the middle point are connected), and the output can be switched to the b contact by the output from the determiner 20 only when the data signal is transmitted.

The switching block 2 for reception will now be described in detail. The reception input 21 is input in parallel to the bandpass filters 22 and 23 having different center frequencies, and is superimposed on the voice signal and the data signal. Notch filters 24 and 25 centered on the frequency of the tone signal A or B
Input in parallel. Furthermore, bandpass filters 22 and 23
The output from the notch filter 24
The outputs of 25 are connected to the 1-contact switches 27 and 28, respectively. Further, the frequency determining device 26 outputs control signals 29 and 30 to the switches 27 and 28, respectively. Here, the tone generators 15 and 16 provided in the switching block 1 for transmission and the band filters 22.2
3 and the notch filters 24 and 25 are closely related in frequency. That is, the center frequency of the tone signal A combined with the voice signal matches the center frequency of the bandpass filter 22 and the notch filter 24, and the center frequency of the tone signal B combined with the data signal is the bandpass filter 2.
3 and the center frequency of the notch filter 25. As a result, when the signal transmitted from the switching device Ax installed in another subscriber telephone line is a voice signal, the tone signal A is superposed on it, so that the two band-pass filters 22 and 23 are used. The high-level tone signal that has passed through the bandpass filter 22 is input to the frequency determiner 26. On the other hand, the frequency component corresponding to the tone signal B is also input through the bandpass filter 23, but the level thereof is very low, and both can be easily identified.
Therefore, it is determined which tone signal is input, and the control signal 30 is output, whereby the switch 28 is closed.
Then, the notch filter 25 removes the component of the tone signal A, and the voice signal is a closed contact switch 28.
It is output to the telephone at the subsequent stage via.

The voice signal is also input to the notch filter 24 in parallel, and is output after the signal component corresponding to the tone signal B is removed. However, since the switch 27 is an open circuit, the computer in the latter stage is Will not be output to.

On the other hand, when the signal transmitted from the other subscriber telephone line switching device is a data signal, a signal having a higher level than that of the band filter 24 is input to the frequency judging device 26 after passing through the band filter 23. Therefore, this is judged, the control signal 29 is output, and the switch 27 is closed circuit.
Then, the data signal from which the component corresponding to the tone signal B has been removed by the notch filter 24 is input to the modem 17 via the switch 27, and is input as a binary encoded data string to a computer or the like in the subsequent stage. ..
In this case, the signal passing through the notch filter 25 is disconnected from the subsequent stage because the switch 28 has an open circuit.

The control signal 19 output from the frequency judging device 20 is also inputted to the judging device 26 on the receiving side, which is judged by the judging device 26 when there is crosstalk due to the signal transmitted by itself. This is a regulation to prevent malfunction. However, it may be omitted if a configuration for preventing malfunction by separately setting the threshold value of the determiner 26 to a high level is adopted.

As described above, two types of signals having different characteristics are selectively and surely transmitted, and at the receiving side, the signal carried to the telephone line is also judged and selectively and surely output to the subsequent stage. I am trying.

[0018]

According to the apparatus of the present invention, tone signals of different frequencies are combined with two signals for discrimination, and at the same time, the currently output signal is judged and exclusively selected and transmitted. As a result, the signals carried on the telephone line can be easily distinguished even if they are the same analog wave.

At the same time, on the receiving side, a bandpass filter having a frequency corresponding to the two tone signals is used to determine which of the received signals is present, and the notch filter is used to ensure the voice signal or data signal from which the tone signal has been removed. You can now selectively take out. Therefore, by simply interposing the device of the present invention between the telephone line, the telephone and the computer, the data transmission and the normal telephone function can be automatically selected, and efficient switching between transmission and reception can be achieved. became.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing the device of the present invention connected to an existing telephone line network.

FIG. 2 is a block diagram showing details of the device of the present invention.

[Explanation of symbols]

 13/14 Mixer 15/16 Tone Generator 18 Switch 20 Data / Voice Evaluator 22/23 Bandpass Filter 24/25 Notch Filter 26 Frequency Evaluator

Claims (1)

[Claims] 1. A combination of means for synthesizing a tone signal with an analog voice signal and means for synthesizing a tone signal of a different frequency after converting a digital data string into an analog data signal, and inputs exclusively. A switching device for transmission for judging either the voice signal or the data signal and transmitting one of them to a telephone line, and a reception signal from another device received via the telephone line for the two tones. A notch on the side that matches the tone signal determined by the frequency determiner while being input to the frequency determiner via the two bandpass filters corresponding to the signals and also input to the two notch filters corresponding to the two tone signals. A data / voice switching device comprising a switching device for reception that outputs a filter.