JPH05260212A - Data terminal equipment - Google Patents

Abstract

PURPOSE:To accurately prevent mis-start when plural terminal equipments are connected to the same telephone circuit. CONSTITUTION:This terminal equipment is provided with terminal connection means L1, L2 and T1, T2 connecting 1st terminal equipment 1c to a telephone circuit 3 and connecting a 2nd terminal equipment to the same telephone circuit 3 via a 1st terminal equipment 1c, with an interruption means 14 interrupting a 2nd terminal equipment 4 when the 1st terminal equipment 1c detects the polarity inversion of the telephone circuit 3, with connection means 6, 12 connecting the 2nd terminal equipment to the telephone circuit 3 when the 1st terminal equipment 1c detects a call signal. The 2nd terminal equipment 4 is interrupted from a communication channel by detecting the polarity inversion signal by the 1st terminal equipment 1c connecting to the same telephone circuit 3 to surely prevent the mis-start of the 2nd terminal equipment by the signal for the communication of the 1st terminal equipment 1c. For example, when the 1st terminal equipment 1c is the terminal equipment of no-ringing communication and the 2nd terminal equipment 4 is a facsimile equipment, the mis-start of the facsimile equipment by an NRS signal for the no-ringing communication is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data terminal device having a second terminal device connected to a telephone line or the like via a first terminal device, and more particularly to a data terminal device connected to the same line as the first terminal device. The present invention relates to a data terminal device that prevents erroneous activation of the second terminal device.

[0002]

2. Description of the Related Art As a first terminal device used in this type of data terminal device, for example, a meter for water, gas, electric power, etc. is automatically metered through a telephone line to collect usage data. There is a no-ringing communication terminal device called by a no-ringing incoming call from a center device. Also,
The second terminal device connected to the same line as the telephone line to which the first terminal device is connected is, for example, a facsimile terminal device (facsimile).

When two or more types of terminal devices share the same telephone line in this way, for example, when the no-ringing communication terminal device which is the first terminal device communicates, the signal of this communication is the second terminal device. It is also supplied to the facsimile, which may cause the facsimile to be erroneously activated.

Conventionally, in order to prevent such an erroneous activation, for example, as disclosed in JP-A-61-200758, a first terminal provided with a filter circuit for removing a signal of a frequency for activating a facsimile. As disclosed in Japanese Patent Laid-Open No. 3-11870, the first terminal device is activated when the first terminal device is activated by the activation of the telephone line by the no-ringing incoming signal in order to enhance the economy. There is a means for preventing the influence on the telephone line due to the erroneous activation of the facsimile by providing means for disconnecting the facsimile, which is the terminal device, from the telephone line.

[0005]

However, the above-mentioned means for disconnecting the second terminal device by the no-ringing incoming signal from the first terminal device in JP-A-3-11870 is not sufficient. This is because some facsimiles use 1300 Hz as a facsimile calling signal, and when an NRS signal including 1336 Hz is received as a no ringing incoming signal (NRS), it is 1300 Hz.
Since the facsimile is close to the facsimile calling signal of Hz, the facsimile closes the direct current circuit, and the second terminal device is erroneously activated to cause a problem that the no-ringing exchange interrupts the no-ringing connection. The ringing call to the facsimile connected to the facsimile communication network is different from the ringing communication of the no ringing communication, and the polarity is not reversed. Although a method is considered that a response is made by connecting it, some facsimiles that can be connected to a facsimile communication network respond by ignoring the polarity inversion even if a facsimile call signal is received after polarity inversion. This is because.

The present invention solves these problems, and an object thereof is to reliably prevent erroneous activation when a plurality of terminal devices are connected to the same telephone line and to communicate with the second terminal device. It is to provide a data terminal device that does not hinder the operation.

[0007]

In order to solve the above-mentioned problems, a data terminal device of the present invention is provided with a first terminal device connected to a telephone line and an identical telephone line via the first terminal device. The terminal connecting means for connecting the second terminal device, the disconnecting means for disconnecting the second terminal device when the first terminal device detects the polarity reversal of the telephone line, and the first terminal device detecting the calling signal. In this case, a connection means for connecting the second terminal device to the telephone line is provided.

[0008]

According to the present invention, when the first terminal device is, for example, a no-ringing communication terminal device, the disconnecting means disconnects the second terminal device from the telephone line when the polarity reversal of the telephone line is detected. .. If the disconnecting means disconnects the second terminal device and then the first terminal device detects a call signal from the telephone line, this call signal is not an NRS signal, and it is determined that the first terminal device is not the non-ringing communication. Then, the disconnecting means connects the second terminal device to the telephone line again. For example, if the second terminal device is a telephone, the bell will ring. After the disconnecting means disconnects the second terminal device, if the first terminal device detects the NRS signal from the telephone line, the first terminal device continues the no-ringing communication with the second terminal device disconnected.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an example of a system configuration diagram of a data terminal device of the present invention. The data terminal device shown in the figure is a plurality of no-ringing communication terminal network control devices 1a, 1b, 1c connected to a telephone line 3 for no-ringing communication.
Via the terminal network control devices 1a, 1b, 1c,
Various meters 2a, 2b for measuring water, gas, electric power, etc.
2c is connected, a facsimile 4 is connected to the same telephone line 3 via the terminal network control devices 1a, 1b, 1c, and a telephone 5 is further connected via the facsimile 4. The terminal network control device 1b is the terminal network control device 1
The terminal network control device 1c is connected to the terminal network control device 1b via a.
And 1a to the telephone line 3. When the facsimile 4 receives an AC signal of 1300 Hz via the telephone line 3, it closes the DC loop and starts facsimile communication. In the embodiment of the present invention, the terminal network control device 1
a, 1b, 1c as the first terminal device, and the facsimile 4
And the telephone 5 as the second terminal device.

FIG. 2 is a block diagram showing the configuration of the terminal network control device 1c. The terminal network control device 1c shown in the figure has line connection terminals L1 and L2 for connecting to the telephone line 3 via the terminal network control devices 1a and 1b, and device connection terminals T1 and T2 for connecting the facsimile 4. It is provided. The line connection terminals L1 and L2 and the device connection terminals T1 and T2
And a switch circuit 14 for connecting or disconnecting the facsimile 4, and a circuit connection terminal L.
A polarity reversal detection circuit 6 that realizes a polarity reversal detection unit that detects the polarity reversal between 1 and L2, and a ringing signal detection circuit 15 that detects a ringing signal that is a bell ringing signal are provided, and an NRS that detects an NRS signal. The detection circuit 7, the semi-closed circuit 13 for half-closed the DC circuit of the telephone line 3, and the NRS
An ANS output circuit 8 for outputting a response signal to the signal,
A modem unit 9 that modulates data and outputs it to the telephone line 3 or demodulates a signal input from the telephone line; one end is connected to the meter 2c via a connection line 10 and the other end is connected to the modem unit 9; It includes a meter interface unit 11 and a control unit 12 that controls the entire operation. Further, the terminal connecting means for connecting the first terminal device to the telephone line 3 and connecting the second terminal device to the same telephone line via the first terminal device is the line connecting terminals L1 and L2 and the device connecting terminal T1. , T2 and the switch circuit 14, disconnection means for disconnecting the second terminal device when the first terminal device detects the polarity reversal of the telephone line is realized by the polarity reversal detection circuit 6, the switch circuit 14, and the control unit 12. There is. If the first terminal device detects a ringing signal that is not an NRS signal, the second terminal
The connecting means for connecting the terminal device to the telephone line is realized by the call signal detection circuit 15, the switch circuit 14, and the control unit 12.

Now, the NRS signal and the ANS signal are the push button (P) of the telephone having two kinds of frequencies of high group and low group.
B) The same signal as the signal is used, and the terminal network control device 1
a indicates NR of PB signal "1", terminal network controller 1b indicates PB signal "2", and terminal network controller 1c indicates PB signal "3".
It shall be used as the S signal. PB signal '2' is 69
It consists of 7Hz and 1336Hz, and PB signal '3' is 69
It is composed of 7 Hz and 1477 Hz.

Further, it is assumed that the configurations of the terminal network control devices 1a and 1b are the same as the configuration of the terminal network control device 1c. The line connection terminals L1 and L2 of the terminal network control device 1b are connected to the terminal connection terminals T1 and T2 of the terminal network control device 1a, and the line connection terminals L1 and L2 of the terminal network control device 1c are terminal connection of the terminal network control device 1b. When the polarity inversion detection circuit 6 detects polarity inversion, the control unit 12 activates the switch circuit 14 to connect the line connection terminals L1 and L2 and the device connection terminals T1 and T2. Only the terminal network control device 1c operates so as to disconnect them.

The no-ringing communication is started by receiving the polarity inversion signal and the NRS signal following the polarity inversion signal from the telephone line 3, and the end of the no ringing communication is performed by receiving the polarity inversion signal again after the start of the no ringing communication. Shall be performed.

Next, the operation of the embodiment of the present invention will be described. First, an operation in which the center device uses the telephone line 3 for no ringing to call the no ringing of the terminal network control device 1c to collect data from the meter 2c will be described.

When the center device makes a no-ringing call, the terminal network control devices 1a, 1b,
The polarity inversion signal 13 is sent to 1c. In the terminal network control device 1c, the polarity inversion detection circuit 6 has line connection terminals L1 and L2.
When the polarity reversal is detected, the switch circuit 14 is activated to disconnect the facsimile 4 connected to the terminal connection terminals T1 and T2 from the line connection terminals L1 and L2. Then, the PB signal '3' is sent as the NRS signal following the polarity inversion signal, but the facsimile 4 has line connection terminals L1 and L.
The PB signal '3' is not transmitted to the facsimile because it has already been separated from 2. Terminal network control device 1c
When the NRS detection circuit 7 receives the PB signal '3', it recognizes that it is an NRS signal and detects that there is no ringing call. After the half-closed circuit 13 half-closed the telephone line, the ANS output circuit 8 is turned on. It activates and outputs a response signal to the telephone line 3. Further, the terminal network control device 1c confirms that the reception of the NRS signal is interrupted, starts transmitting the ANS signal, and activates the switch circuit 14 to activate the facsimile 4 connected to the terminal connection terminals T1 and T2. Connect to the line connection terminals L1 and L2.

In the terminal network control devices 1a and 1b, even when the polarity reversal detection circuit 6 detects the polarity reversal of the line connection terminals L1 and L2, the switch circuit 14 is not activated, so that the line connection terminal L is not activated.
1, L2 and the terminal connection terminals T1, T2 are kept connected. P as the NRS signal following the polarity inversion signal
B signal '3' is sent, but the NRS detection circuit 7 outputs PB
Even if the signal '3' is received, it is not an NRS signal and is not recognized as a no ringing call.

The terminal network control device 1c which has started the no-ringing communication uses the modem unit 9 and the meter interface unit 11 to transmit the meter reading value from the meter 2c through the telephone line 3. In the no ringing communication of the terminal network control device 1c, the polarity reversal detection circuit 6 is again connected to the line connection terminal L1,
When the polarity reversal of L2 is detected, the semi-closed circuit 13 is activated, and the DC circuit is opened to finish.

Next, the operation in which the center device uses the telephone line 3 for no ringing to call the no ringing of the terminal network control device 1b to collect the data from the meter 2b will be described. When the center device makes a no ringing call, the terminal network control device 1 is sent via the telephone line 3.
The polarity inversion signal 13 is sent to a, 1b, and 1c. When the polarity reversal detection circuit 6 detects the polarity reversal of the line connection terminals L1 and L2, the terminal network control device 1c switches the switch circuit 14
To disconnect the facsimile 4 connected to the terminal connection terminals T1 and T2 from the line connection terminals L1 and L2.
PB signal '2' as NRS signal following polarity inversion signal
Will be sent. The facsimile 4 has a line connection terminal L1,
Since it has already been disconnected from L2, the PB signal "2" is not transmitted to the facsimile. Therefore, the PB signal "2" is a signal of 1336 Hz, which is close to the AC signal of 1300 Hz that activates the facsimile 4, but the facsimile 4 is disconnected, so that the facsimile 4 is not erroneously activated.

When the terminal network control unit 1b receives the PB signal "2" by the NRS detection circuit 7, it judges that the signal is an NRS signal and starts the no ringing communication. The ANS output circuit 8 is activated to output a response signal to the telephone line 3. The terminal network control device 1b that has started the no-ringing communication uses the modem unit 9 and the meter interface unit 11 to transmit the meter reading value and the like from the meter 2b through the telephone line 3. The no-ringing communication of the terminal network control device 1b ends when the polarity reversal detection circuit 6 detects the polarity reversal of the line connection terminals L1 and L2 again to activate the semi-closed circuit 13 and open the DC circuit.

In the terminal network control devices 1a and 1b, the polarity reversal detection circuit 6 does not activate the switch circuit 14 even if the polarity reversal detection circuit 6 detects the polarity reversal of the line connection terminals L1 and L2.
1, L2 and the terminal connection terminals T1, T2 are kept connected. Next, the terminal network control devices 1a and 1c follow the polarity inversion signal, and then P, which is the NRS signal of the terminal network control device 1b.
Although the B signal “2” is received, the NRS detection circuit 7 does not determine the no ringing call even if the PB signal “2” is received. Therefore, the semi-closed circuit 13 and the ANS output circuit 8 are not activated and the no ringing communication is started. do not do. After confirming that the reception of the NRS signal to the terminal network control device 1b is interrupted, the terminal network control device 1c activates the switch circuit 14 to connect the facsimile 4 connected to the terminal connection terminals T1 and T2 to the line connection terminal L1. , L2.

Next, the operation when the telephone 5 receives a call from another telephone via the telephone line 3 will be described.

To call the telephone 5 connected to the telephone line 3, a polarity inversion signal is output from the exchange through the telephone line 3, and then a calling signal for ringing the bell of the telephone 5 is output. When the polarity inversion signal is received, the terminal network control device 1c
When the polarity reversal detection circuit 6 detects the polarity reversal of the line connection terminals L1 and L2, the switch circuit 14 is activated to disconnect the facsimile 4 connected to the terminal connection terminals T1 and T2 from the line connection terminals L1 and L2. Therefore, the telephone 5 is also disconnected from the line connection terminals L1 and L2. However, if there is a call signal after the polarity inversion signal, the terminal network control device 1
c activates the switch circuit 14 to detect the call signal by the call signal detection circuit 15 and activates the terminal connection terminals T1, T
Facsimile 4 connected to 2 is connected to line L
1 and L2 are connected. By this operation, the calling signal is supplied to the telephone 5 and sounds. There is an exchange that does not output the polarity reversal signal before the ringing signal is generated on the telephone line 3, but no ringing communication is premised on the polarity reversal. If the polarity reversal does not occur, the terminal network control device 1c determines the line connection terminal L1. This is the same as the state in which the telephone 5 is directly connected to the telephone line 3 because the L2 and the terminal connection terminals T1 and T2 are not separated. Telephone line 3 to facsimile 4
Even if a signal of 1300 Hz for calling the terminal is given, the terminal network control device 1c has the line connection terminal L because there is no polarity inversion.
Do not separate the terminal connection terminals T1 and T2 from the terminals 1 and L2. Therefore, the state in which the facsimile 4 is directly connected to the telephone line 3 is maintained, and communication is not hindered.

As described above, since the NRS signal after polarity reversal for no ringing communication is not transmitted to the facsimile 4, erroneous activation does not occur.

In the embodiment of the present invention, the erroneous activation prevention of the facsimile 4 activated by the AC signal of 1300 Hz and the facsimile 4 activated by the NRS signal are symmetrical, but any of the terminal network control devices 1a, 1b, 1c is used. If the terminal network control device 1c activates the switch circuit 14 to disconnect the facsimile 4 connected to the terminal connection terminals T1 and T2 from the line connection terminals L1 and L2 during the non-ringing communication, the modem section 9 is used. It is also possible to deal with the case where the existing modem communication causes erroneous activation of the terminals connected to the terminal connection terminals T1 and T2.

[0026]

As described above, according to the data terminal device of the present invention, the first terminal device connected to the same telephone line detects the polarity inversion signal and disconnects the second terminal device from the communication line. Since it is possible to prevent the erroneous activation of the second terminal device due to the communication signal of the first terminal device,
It is possible to obtain the effect of not hindering the operation of the terminal device.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a data terminal device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a terminal network control device used for the device.

[Explanation of symbols]

 1a, 1b, 1c Terminal network control device 3 Telephone line 4 Facsimile 5 Telephone 6 Polarity reversal detection circuit 7 NRS detection circuit 8 ANS output circuit 12 Controller 13 Half closed circuit 14 Switch circuit 15 Ring signal detection circuit

Front Page Continuation (72) Inventor Takuo Shimada 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Inventor Masaaki Sakata 1006, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Seijiro Nishima 1-2-12 Benten, Minato-ku, Osaka City, Osaka NT T Kansai Telecon Co.

Claims (1)

[Claims] 1. A first terminal device connected to a telephone line, a terminal connecting means for connecting a second terminal device to the telephone line via the first terminal device, and the first terminal device. Disconnecting means for disconnecting the second terminal device when detecting polarity reversal of the telephone line, and connection for connecting the second terminal device to the telephone line when the first terminal device detects a calling signal. And a data terminal device.