JP3828291B2 - Data transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[0002]
The present invention relates to a data transmission apparatus, and more particularly to a data transmission apparatus that can normally transmit and receive data with no polarity being connected to a master unit and a plurality of extension master units installed in a living room.
[Prior art]
[0003]
Conventionally, as this type of data transmission apparatus, as shown in the block diagram of FIG. 6, a data transmission apparatus composed of a master unit 51 connected by a cable L51 and a plurality of additional master units 52, 52, 52,. Has been proposed.
[0004]
FIG. 7 is a block diagram showing the configuration of the base unit 51 of FIG. 6. The base unit 51 includes a power supply circuit 60, an indoor calling circuit 61, a gate array (hereinafter referred to as GA) 62, a handset 63, Voice transmission / reception circuit 64, voice AD / DA conversion circuit 65, data transmission circuit 66, data reception circuit 67, ringing tone amplification circuit 68, loud speaker 69, unbalance-balance conversion circuit 70, A control device (hereinafter referred to as CPU) 71 is provided, and the data transmission circuit 66 includes a low-pass filter (hereinafter referred to as LPF) 66a and a DC component removal circuit 66b.
[0005]
FIG. 8 is a block diagram showing the configuration of the extension master unit 52 of FIG. 6. The extension master unit 52 includes a power supply circuit 80, an indoor calling circuit 81, a gate array (hereinafter referred to as GA) 82, and a handset. 83, voice transmission / reception circuit 84, voice AD / DA conversion circuit 85, data transmission circuit 86, data reception circuit 87, ringing tone amplification circuit 88, loudspeaker 89, and unbalance-balance conversion circuit 90. And a control circuit (hereinafter referred to as CPU) 91, and the data receiving circuit 87 includes a data signal amplifying circuit 87a and a waveform shaping circuit 87b.
[0006]
In the data transmission apparatus configured as described above, when the extension master unit 52 is called from the master unit 51 via the cable L51 as shown in the block diagram of FIG. 6, the room of the master unit 51 shown in the block diagram of FIG. When the calling circuit 61 is appropriately called (not described in detail), the data signal S51 containing the calling signal component is output to the data transmission circuit 66 via the GA 62. The data signal S51 input to the data transmission circuit 66 passes through the LPF 66a, and is input to the unbalance-balance conversion circuit 70 as the data signal S52 from which the DC component has been removed by the DC component removal circuit 66b. The transmitted data signal S53 is transmitted to the extension master unit 52 via the cable L51.
[0007]
The data signal S53 transmitted to the extension master unit 52 is input to the unbalance-balance conversion circuit 90 of the extension master unit 52 shown in the block diagram of FIG. 87 is output. The data signal S54 input to the data receiving circuit 87 is output to the waveform shaping circuit 87b as the data signal S55 amplified by the data signal amplifier circuit 87a. The waveform shaping circuit 87b cuts the input data signal S55 at a predetermined threshold potential and sends it to the CPU 91 via the GA 82 as a data signal S56 having a waveform shaped. The CPU 91 which has detected the data signal S56 as input causes the ringing sound amplified through the ringing tone amplification circuit 88 to ring on the loudspeaker 89, thereby calling the user of the parent unit 51 to use the additional parent unit 52. Inform the person. Further, when the user of the called extension master unit 52 answers the call using the handset 83, a call is established between the handset 63 used by the user of the base unit 51 called via the cable L51 (details). Not).
[Problems to be solved by the invention]
[0008]
However, since the conventional data transmission apparatus is configured as described above, if the polarity of the cable L51 connected to the extension master unit 52 is reversed as shown in the block diagram of FIG. The balance-balance conversion circuit 90 receives a data signal S63 having a pulse waveform that is inverted up and down, and this data signal S63 is a data signal that has been appropriately subjected to signal processing (S64, S65) in the extension master unit 52 as described above. Although the data signal S66 has a pulse waveform different from that of the data signal S51 output from the GA 62 of the master unit 51, the abnormal operation caused by connecting the cable L51 with the wrong polarity is input to the GA 82 as S66. There is a problem that it is easy to occur. Therefore, it is necessary to connect the cables with the same polarity (connection). Difficulties such as likely to occur there has been.
[0009]
The present invention has been made to solve the above-mentioned problems. By making the polarity of the cable connecting the master unit and the extension master unit non-polar, data transmission / reception between the master unit and the extension master unit can be performed normally. An object of the present invention is to provide a data transmission device that performs and improves the workability during construction of the device.
[Means for Solving the Problems]
[0010]
In order to achieve such an object, the data transmission apparatus of the present invention is a data transmission apparatus that removes a DC component and transmits / receives a data signal via a cable, and reverses the polarity of the received data signal by inverting the polarity. A data signal inverting circuit that is a data signal, a first waveform shaping circuit that cuts out a waveform of the polarity-inverted data signal from the data signal inverting circuit at a threshold potential to form a waveform-shaped data signal, and the received data signal is a threshold potential To detect which one of the waveform shaping data signals input from the second waveform shaping circuit input from the first and second waveform shaping circuits has changed first. The cable connection is made non-polar by providing preceding waveform detection output means for outputting the waveform shaping data signal which has been changed first.
[0011]
According to such a data transmission device, when a data signal output from a master unit connected by a cable and from which a direct current component has been removed is transmitted to the extension master unit, the data in the extension master unit is transmitted regardless of the polarity of the cable to be connected. Since the waveform-formed data signal that has been appropriately signal-processed has the same waveform as the data signal output from the master unit, data transmission / reception must be performed normally between the master unit and the extension master unit via a nonpolar cable. Thus, the workability at the time of construction of the apparatus can be improved.
DETAILED DESCRIPTION OF THE INVENTION
[0012]
Hereinafter, a preferred embodiment to which a data transmission apparatus of the present invention is applied will be described as an embodiment with reference to the drawings.
[0013]
As shown in the block diagram of FIG. 1, the television door phone apparatus of the present invention is composed of a master unit 1 and a plurality of additional master units 2, 2, 2,... Connected by a cable L1.
[0014]
FIG. 2 is a block diagram showing the configuration of the master unit 1 of FIG. 1. The master unit 1 is connected to a commercial power source and supplies a DC power source as a circuit power source necessary for operating the master unit 1 into the circuit. A circuit 10, an indoor calling circuit 11 that is appropriately called (not described in detail) to call the (multiple) additional base units 2 connected by the cable L 1, and a control circuit (hereinafter referred to as a CPU) described later. ) A gate array (hereinafter referred to as GA) 12 for controlling the operation of each part (each circuit) constituting the parent device 1 by the data signal activated and inputted / outputted by 21, and the user of the parent device 1 adds the extension parent device A transmitter / receiver 13 used to establish a call with the user 2, a voice transmitter / receiver circuit 14 for amplifying a voice transmitted / received by the transmitter / receiver 13, and a voice transmitted / received between the GA 12 and the voice transmitter / receiver circuit 14. Analog / digital conversion or A voice AD / DA conversion circuit 15 that performs digital / analog conversion, a data transmission circuit 16 that removes and transmits a DC component of the data signal output from the GA 12, and an unbalance-balance conversion circuit 20 that is transmitted through the cable L1 and is described later. A data receiving circuit 17 for amplifying a data signal via the signal, shaping the waveform and sending it to the GA 12; a ringing tone amplifying circuit 18 for amplifying the ringing tone output from the CPU 21; and a ringing tone via the ringing tone amplifying circuit 18 A loudspeaker 19 that rings, an unbalanced-balanced conversion circuit 20 that performs unbalanced-balanced conversion or balanced-unbalanced conversion of a transmitted / received data signal, and a CPU 21 that controls the operation of each unit (each circuit). Yes. The data transmission circuit 16 also includes a low-pass filter (hereinafter referred to as LPF) 16a that passes the data signal output from the GA 12, and a DC component removal circuit 16b that removes and outputs a DC component of the data signal via the LPF 16a. It consists of
[0015]
FIG. 3 is a block diagram showing the configuration of the extension master unit 2 of FIG. 1. The extension master unit 2 is connected to a commercial power source, and a DC power source is provided in the circuit as a circuit power source necessary for operating the extension master unit 2. A power supply circuit 30 to be supplied, an indoor calling circuit 31 that is appropriately called (not described in detail) to call the parent device 1 or other extension parent device 2 connected by the cable L1, and a control circuit (to be described later) Hereinafter, a gate array (hereinafter referred to as GA) 32 for controlling the operation of each unit (each circuit) constituting the extension master unit 2 by a data signal activated and input / output by the CPU 41), and the extension master unit 2 A handset 33 used for establishing a call with a user of the base unit 1 or another extension base unit 2, a voice handset circuit 34 for amplifying the voice transmitted and received by the handset 33, Transmission / reception between GA 32 and voice transmission / reception circuit 34 A voice AD / DA conversion circuit 35 that performs analog / digital conversion or digital / analog conversion of the received voice, a data transmission circuit 36 that removes the DC component of the data signal output from the GA 32, and transmits the cable L1 A data receiving circuit 37 for amplifying and shaping a data signal via an unbalance-balance conversion circuit 40, which will be described later, and sending it to the GA 32; a ringing tone amplification circuit 38 for amplifying the ringing tone output from the CPU 41; A loudspeaker 39 that rings a ringing tone via the sound amplification circuit 38, an unbalance-balance conversion circuit 40 that performs unbalance-balance conversion or balance-unbalance conversion on a transmitted / received data signal, and the above-described components (each circuit) And a CPU 41 for controlling the operation. Further, as shown in the block diagrams of FIGS. 4 and 5, the data receiving circuit 37 includes a data signal amplifying circuit 37a for amplifying the data signal via the unbalance-balance converting circuit 40 and a data signal amplifying circuit 37a. A data signal inversion circuit 37b that outputs a polarity-inverted data signal in which the polarity of the data signal is inverted, and a polarity-inverted data signal that has passed through the data signal inversion circuit 37b are cut out at a predetermined threshold potential, and a first waveform is output. A waveform shaping circuit 37c, a second waveform shaping circuit 37d for cutting out and shaping a data signal from the unbalanced-balanced conversion circuit 41 at a predetermined threshold potential, and the first and second waveform shaping. The waveform shaping data signals output from the circuits 37c and 37d are respectively input to detect which one has changed the waveform first, and the data signal that has been changed first is output. Waveform detection output circuit is composed of a (prior waveform detection output means) 37e.
[0016]
The indoor call circuit 11 is connected to the first input terminal P1 of the GA 12 of the base unit 1, and the output side of the data receiving circuit 17 connected to one end of the unbalance-balance conversion circuit 20 is connected to the second input terminal P2. The first output terminal P3 is connected to one end of the unbalance-balance conversion circuit 20 via the LPF 16a constituting the data transmission circuit 16 and the DC component removal circuit 16b, and the output side of the second output terminal P4 is connected to the loudspeaker 19. The input side of the connected ringing tone amplifier circuit 18 is connected to the first input / output terminal P5 via the CPU 21 and to the second input / output terminal P6 via the voice AD / DA conversion circuit 15 and the voice transmission / reception circuit 14. A receiver 13 is connected to each other, and cable connection terminals T1 and T2 connected to the cable L1 are connected to the other end of the unbalance-balance conversion circuit 20, respectively.
[0017]
The output of the data receiving circuit 37 in which the indoor calling circuit 31 is connected to the first input terminal P11 of the GA 32 of the extension base unit 2 and the input side is connected to one end of the unbalance-balance conversion circuit 40 to the second input terminal P12. The first output terminal P13 is connected to the input side of the data transmission circuit 36 whose output side is connected to one end of the unbalance-balance conversion circuit 40, and the second output terminal P14 is connected to the loudspeaker 39 on the output side. The input side of the ringing tone amplification circuit 38 is a CPU 41 at the first input / output terminal P15, and a handset 33 via the voice AD / DA conversion circuit 35 and the voice transmission / reception circuit 34 at the second input / output terminal P16. Cable connection terminals T11 and T12 connected to the cable L1 are connected to the other end of the unbalanced-balanced conversion circuit 40, respectively. Further, one end of the unbalance-conversion circuit 40 is connected to an input side of a data signal amplification circuit 37a constituting the data reception circuit 37 shown in the block diagrams of FIGS. 4 and 5, and an output of the data signal amplification circuit 37a is connected. The input side of the first waveform shaping circuit 37c and the input side of the second waveform shaping circuit 37d via the data signal inverting circuit 37b are respectively connected to the sides, and the outputs of the first and second waveform shaping circuits 37c and 37d are connected. The input side of the preceding waveform detection output circuit 37e whose output side is connected to the second input terminal P12 of the GA 32 is connected to this side.
[0018]
The operation of the data transmission apparatus configured as described above will be described below.
[0019]
As shown in the block diagram of FIG. 1, when the extension master unit 2 is called from the master unit 1 via the cable L1, the indoor calling circuit 11 of the master unit 1 shown in the block diagram of FIG. If not, the data signal S1 containing the calling signal component is output from the first output terminal P3 of the GA 12 to the data transmission circuit 16. The data signal S1 input to the data transmission circuit 16 passes through the LPF 16a and is input to the unbalance-balance conversion circuit 20 as the data signal S2 from which the DC component has been removed by the DC component removal circuit 16b. The data signal S3 is input to the cable connection terminals T1 and T2.
[0020]
Here, the polarity of the cable L1 connected between the cable connection terminals T1 and T2 of the base unit 1 and the cable connection terminals T11 and T12 of the extension base unit 2 is reversed and connected, unlike the block diagram of FIG. Then, the polarity of the data signal S3 input to the cable connection terminals T1 and T2 of the base unit 1 is inverted to the cable connection terminals T11 and T12 of the extension base unit 2 shown in the block diagram of FIG. 4 via the cable L1. Input as data signal S4. The data signal S4 is input to the unbalance-balance conversion circuit 40, and is output to the data reception circuit 37 as a data signal S5 subjected to balance-unbalance conversion.
[0021]
The data signal S5 input to the data receiving circuit 37 is input to the data signal inverting circuit 37b and the second waveform shaping circuit 37d as the data signal S6 amplified by the data signal amplifying circuit 37a. The data signal S6 input to the data signal inversion circuit 37b is input to the first waveform shaping circuit 37c as the polarity inversion data signal S7 with the polarity inverted, and the waveform shaping data signal is cut and waveform-shaped at a predetermined threshold potential. The signal is input to the preceding waveform detection output circuit 37e as S8. On the other hand, the data signal S6 inputted to the second waveform shaping circuit 37d is inputted to the preceding waveform detection output circuit 37e as a waveform shaping data signal S9 which is cut off at a predetermined threshold potential without being inverted in polarity and shaped. The preceding waveform detection output circuit 37e, to which the waveform shaping data signals S8 and S9 are respectively input, sends the waveform shaping data signal S8 whose waveform is changed first among the waveform shaping data signals S8 and S9 to the CPU 41 via the GA 32.
[0022]
On the other hand, the polarity of the cable L1 connected between the cable connection terminals T1 and T2 of the base unit 1 and the cable connection terminals T11 and T12 of the extension base unit 52 is normal as shown in the block diagram of FIG. If connected, the data signal S3 input to the cable connection terminals T1 and T2 of the base unit 1 is sent to the cable connection terminals T11 and T12 of the extension base unit 2 shown in the block diagram of FIG. 5 via the cable L1. Input without inversion. The data signal S3 is input to the unbalance-balance conversion circuit 40, and is output to the data reception circuit 37 as a data signal S10 subjected to balance-unbalance conversion.
[0023]
The data signal S10 input to the data receiving circuit 37 is input to the data signal inverting circuit 37b and the second waveform shaping circuit 37d as the data signal S11 amplified by the data signal amplifying circuit 37a. The data signal S11 input to the data signal inversion circuit 37b is input to the first waveform shaping circuit 37c as a polarity inversion data signal S12 (the same waveform as the data signal S6 at the time of cable connection polarity inversion). A waveform shaping data signal S13 (same waveform as the waveform shaping data signal S9 when the cable connection polarity is inverted) cut and waveform-shaped at the predetermined threshold potential is input to the preceding waveform detection output circuit 37e. On the other hand, the data signal S11 input to the second waveform shaping circuit 37d is not waveform-inverted, but is cut out at a predetermined threshold potential and shaped into a waveform-shaped data signal S14 (waveform-shaped data signal S8 when the cable connection polarity is inverted). Is input to the preceding waveform detection output circuit 37e. The preceding waveform detection output circuit 37e, to which the waveform shaping data signals S13 and S14 are respectively input, sends the waveform shaping data signal S14 whose waveform has been changed first among the waveform shaping data signals S13 and S14 to the CPU 41 via the GA 32.
[0024]
Therefore, the data signal S1 output from the GA 12 of the master unit 1 is input to the CPU 41 as the waveform forming data signals S8 and S14 having the same waveform, which are appropriately processed by the data receiving circuit 37 of the extension master unit 2. Thus, the ringing sound amplified by the CPU 41 having detected the waveform forming data signals S8 and S14 via the ringing sound amplification circuit 38 is sounded by the loudspeaker 39, and the call from the user of the main unit 1 is added to the parent. Can be notified to the user of the machine 2, and when the user of the called extension main unit 2 answers the call using the handset 33, the transmission of the user of the base unit 1 called through the cable L1 is used. The base unit 1 and the additional base unit 2 connected via the cable L1 such as a call is established between the receivers 13 (not described in detail) and operate normally regardless of the polarity of the cable L1. .
[0025]
In the above embodiment, the case where the extension master unit 2 is called from the master unit 1 via the cable L1 has been described. However, the call from the extension master unit 2 to the master unit 1 via the cable L1, which is not described in detail, the extension master unit 2 Calling between the two can be performed normally regardless of the polarity of the cable L1. In the above embodiment, the preceding waveform detection / output function provided in the extension master unit is added to the data receiving circuit. However, a similar function may be added to the GA.
【The invention's effect】
[0026]
As is apparent from the above description, according to the data transmission apparatus of the present invention, data transmission / reception between the master unit and the extension master unit can be performed by making the polarity of the cable connecting the master unit and the extension master unit non-polar. Can be performed normally, and abnormal operation due to the wrong polarity of the cable connection can be eliminated, so that the workability during construction of the apparatus can be improved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the overall configuration of an embodiment of a data transmission apparatus of the present invention.
FIG. 2 is a block diagram showing the configuration of the master unit of FIG. 1 and the waveform of a data signal to be transmitted.
FIG. 3 is a block diagram showing a configuration of the extension base unit in FIG. 1;
4 is a block diagram showing a configuration of a data receiving circuit and a waveform of a data signal to be transmitted when the polarity of a cable connecting the extension master unit of FIG. 3 is reversed.
5 is a block diagram showing a configuration of a data receiving circuit and a waveform of a data signal to be transmitted when the polarity of a cable connecting the extension base unit of FIG. 3 is normal. FIG.
FIG. 6 is a block diagram showing an overall configuration of a conventional data transmission apparatus.
7 is a block diagram showing the configuration of the master unit of FIG. 6 and the waveform of a data signal to be transmitted.
8 is a block diagram showing the configuration of the extension base unit of FIG. 6 and the waveform of a data signal to be transmitted.
FIG. 9 is a block diagram showing the configuration of the extension master unit and the waveform of the transmitted data signal when the polarity of the cable connecting the extension master unit of FIG. 8 is reversed.
[Explanation of symbols]
37b ··· Data signal inversion circuit 37c ··· First waveform shaping circuit 37d ··· Second waveform shaping circuit 37e · · · Predecessor waveform detection output means (preceding waveform detection output circuit)
L1 ... Cable S1, S6, S11 ... Data signal S7, S12 ... Polarity reversal data signal S8, S9, S13, S14 ... Waveform shaping data signal

Claims (1)

A data transmission device that removes a direct current component and transmits / receives a data signal (S1) via a cable (L1),
A data signal inversion circuit (37b) that inverts the polarity of the received data signals (S6, S11) to make the polarity inverted data signals (S7, S12);
A first waveform shaping circuit (37c) which cuts out the waveform of the polarity inversion data signal from the data signal inversion circuit at a threshold potential to form a waveform shaping data signal (S8, S13);
A second waveform shaping circuit (37d) that cuts out the received data signal at a threshold potential and shapes it into a waveform shaped data signal (S9, S14);
A preceding waveform detection output for detecting which one of the two waveform shaping data signals input from the first and second waveform shaping circuits has changed first and outputting the waveform shaping data signal that has changed first. A data transmission device comprising: a means (37e) for making the connection of the cable non-polar.

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