JPS6256710B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a network control device connected to a subscriber telephone line. In particular, the present invention relates to a network control device that can determine the priority of line use for telephone calls and data communications and switch lines according to this priority. In recent years, devices in which a center device collects data from terminal devices in remote locations using subscriber telephone lines (hereinafter simply referred to as "telephone lines"), such as water supply systems,
Automatic meter reading devices that automatically read the consumption of gas, electricity, etc. are being put into practical use. This type of data collection device using a telephone line uses the telephone line to transmit data by utilizing the time when no telephone calls are being made. Conventional devices for this purpose have a call priority function that does not interfere with calls, a no-ringing connection function that connects to the telephone line without ringing the telephone bell during data transmission, and a function that uses a small amount of current from the telephone line as an operating power source. It has functions such as a station power supply operation function that operates in In addition, this type of data collection device that uses telephone lines mainly has a terminal call reception function (polling) that activates the terminal device from the center device, but as this data collection device has become widespread, the purpose of its use has also changed. There is a demand for a device that has not only a terminal call reception function but also a terminal transmission function (calling) for activating a center device from a terminal device. for example,
Reporting failure information for collecting sales volume information in vending machine management equipment, reporting when an abnormality occurs for regular condition monitoring in equipment management equipment, automatic meter reading of ordinary household meters, and reporting in the event of fire or theft, etc. is expected to develop and expand into a variety of uses and services. However, when adding a terminal calling function to a data collection device that uses a telephone line, it is necessary to consider the call priority function and the no-ringing connection function, as in the case of receiving a terminal call. On the other hand, when a conventional telephone line is used exclusively for data communication, a network control device having an automatic call/receiver function is not shared with telephone calls, so call priority functions and no-ringing connection functions are not taken into consideration. The present invention improves this point, and aims to provide a network control device that can prioritize the use of telephone lines and switch connections between telephone lines and data communications in accordance with the priorities. shall be. In particular, the object is to provide a network control device equipped with a no-ringing function that can switch telephone lines according to three priority levels: call priority, equal priority for call and data communication, and data communication priority. It is something. The present invention is arranged on the subscriber side of a subscriber telephone line and configured to allow connection of a telephone or one or more terminal devices to the subscriber telephone line,
In response to a call request from the terminal device, selective dialing information is sent to the subscriber telephone line to establish a connection with the center side device, and after this connection is completed, data communication occurs between the terminal device and the center side device. In the network control device that controls the network control device, there is provided means for giving priority information indicating the priority of using the telephone line according to the information from the terminal device side, and when the information of data communication priority is given from this means, the above-mentioned method is provided. Regardless of the state of use of the telephone line, when a calling request signal sent from the terminal device is received, the telephone is disconnected from the telephone line and becomes ready for data communication, and when information regarding call priority is given from the above means; The present invention is characterized by comprising a control means that connects the telephone to the telephone line and makes it possible to make a call regardless of the usage state of the telephone line when the off-hook of the telephone is detected. An embodiment of the present invention will be described based on the drawings.
FIG. 1 is a block diagram of essential parts of an embodiment of the present invention. In FIG. 1, the system is roughly divided into a telephone line 1, a telephone set 2, terminal devices 3 and 4, and a network control device 5 to which these are connected, which is a feature of the present invention. Although FIG. 1 shows the connection state of only the terminal device 3 in detail for easy understanding, the same applies to other terminal devices. That is, the telephone line 1 is connected to an automatic incoming network control circuit 8 via a switch circuit 7.
This automatic incoming network control circuit 8 includes a code transmitting circuit 9
is connected to. This code transmission circuit 9 is connected to the terminal device 3 via a switch circuit 10. An automatic dialing circuit 11 is connected to this terminal device 3. Here, one output of this terminal device 3 is led to an automatic dialing circuit 11 via the switch circuit 10. Further, the automatic dialing circuit 11 is connected to the telephone line 1.
It is connected via a switch circuit 14 to a line monitoring line 13 connected to the line monitoring line 13 . The output of this line monitoring circuit 13 is led to an automatic dialing circuit 11. One output of this automatic dial circuit 11 is sent to the control terminal of the switch circuit 10, another output is sent to the control terminal of the switch circuit 14, another output is sent to the control terminal of the switch circuit 7, and another output is sent to the control terminal of the switch circuit 7. are respectively guided to the automatic incoming network control circuit 8. Further, an off-hook detection circuit 15 is connected between the telephone set 2 and a switching contact of the switch circuit 7 connected to the telephone line 1. The output of the off-hook detection circuit 15 is led to the automatic incoming network control circuit 8 and the automatic dialing circuit 11, respectively. In addition, 18 and 19 in Figure 1 are cables (4
(core cable), which connects the network control device 5 and the terminal devices 3 and 4, respectively. This cable 1
The types of interface lines 8 and 19 are data signal lines 18 ₁ , 19 ₁ and common return lines 18 ₂ , 19
₂ , call request signal lines 18 ₃ , 19 ₃ and call acceptance signal lines 18 ₄ , 19 ₄ . Further, in FIG. 1, 21 to 23 indicate signal lines, respectively. FIG. 2 is an operation time chart at the time of terminal transmission, showing the input or output signal waveforms at the points indicated by the crosses in FIG. 1. In Fig. 2, a is a calling request signal;
b, c, and e represent control signals, d represents a call acceptance signal, and f represents a data signal, respectively. Further, in the data signal f in FIG. 2, numeral 2 indicates priority information, numeral numeral dial information, and data information, respectively. With such a circuit configuration, switch circuits 7 and 10
is usually connected to the signal lines 21 and 22,
When the terminal receives a call, the automatic receiving network control circuit 8
works. When the terminal is making a call, the switch circuit 7 is turned off as necessary, and the switch circuit 10 is turned off to the signal line 2.
The switch is controlled to the 3rd side. Automatic incoming network control circuit 8
The terminal receives a call signal for no-ringing connection when a terminal call arrives, operates the station power supply, and sends a terminal selectable signal. The code transmission circuit 9 performs terminal selection code reception, data transmission/reception, response signal transmission after terminal selection, and data modulation/demodulation. The off-hook detection circuit 15 detects the off-hook state of the telephone 2 based on changes in current or impedance of the telephone circuit. The line monitoring circuit 13 monitors the usage status of the telephone line 1 when a terminal makes a call. The switch circuit 14 is normally in an open state, and is controlled to open or close as necessary when the terminal makes a call. The automatic dialing circuit 11 functions as an interface circuit with the terminal devices 3 and 4 when making a terminal call, and performs functions such as receiving selected dialing information, sending out automatic dialing, sending out a monitoring timer signal, and determining priority information. The terminal devices 3 and 4 have an interface circuit with the network control device 5, and perform sending of priority information and selection dial information, data transmission and reception, and the like. The operation of the network control device 5, which is a feature of the present invention, will be explained in more detail. First, let me explain the operation when the terminal receives a call.
At this time: The switch circuits 7 and 10 are connected to the signal lines 21 and 22, respectively. After the polarity of the telephone line 1 is reversed, the automatic incoming network control circuit 8 is supplied with a minute current from the telephone line 1 and receives a calling signal for no-ringing connection sent from a center-side device (not shown). After this, the terminal device 3,
A terminal selectable signal for 4 is sent to the center side device. After that, the code transmitting circuit 9 receives the terminal selection code sent from the center side device, selects and connects the specified terminal device 3 or 4, sends a response signal to the center side device, and enters a communication ready state. .
Thereafter, data is transmitted and received between the center side device and the terminal device 3 or 4 via the data signal line 18 ₁ or 19 ₁ using the data modulation/demodulation function of the code transmission circuit 9 . When the telephone 2 is taken off-hook during communication, a loop current flows through the telephone circuit, causing the off-hook detection circuit 15 to operate. In response to this off-hook detection output, the operating current of the automatic incoming network control circuit 8 is stopped, and the transmission of the response signal is also stopped, the automatic incoming network control circuit 8 is disconnected from the telephone line 1, and the use of the telephone 2 is prioritized. At this time, the center side device performs a recovery operation by stopping the response signal. In this manner, when a terminal call is received, a system is adopted in which the calling side is given priority over data communication due to the nature of data communication, such as automatic meter reading. Furthermore, when the normal data communication ends, the restoration operation of the center side device restores the polarity inversion state of the telephone line 1 to the normal state, and the operating current of the automatic incoming network control circuit 8 stops. At the same time, the sending of response signals is stopped, and everything is restored to its initial state. Next, the operation of the terminal when making a call will be explained based on the operation time chart shown in FIG. For the sake of simplicity, only the case where a terminal call is made from the terminal device 3 will be described, but the same applies to the case where a call is made from any terminal device. First, the priority for using telephone line 1 is as shown in the following table.

[Table] There are three priority types: call priority, call and data communication equal, and data communication priority. According to this priority, calls are prioritized for less urgent matters such as a breakdown in a vending machine, and even if data communication is in progress, it is stopped and calls are given priority. Furthermore, data communication is prioritized for highly urgent matters such as disaster prevention or crime prevention, and even if a call is in progress, it is stopped and data communication is prioritized. In addition, for somewhat more urgent matters such as air conditioning equipment, communications and data communications are handled equally, and the telephone line is switched on a first-come, first-served basis until the end of the call or data communications. That is, the terminal device 3 sends a calling request signal a to the network control device 5 at an arbitrary time (a, t ₁ in FIG. 2). In the network control device 5, the switch circuit 10 is switched from the signal line 22 side to the 23 side by the control signal e, and the data signal line ₁₈₁ from the terminal device 3 is connected to the automatic dialing circuit 11. Next, the automatic dialing circuit 11 receives priority information transmitted as serial data from the terminal device 3 via the data signal line ₁₈₁ (FIG. 2, f, t ₁₁ ). The line monitoring circuit 13 monitors the usage status of the telephone line 1, and when the telephone line 1 is not in use, after a predetermined time, the switch circuit 7 is switched from the signal line 21 by the control signal b to turn it off, and the telephone line 2 and the telephone Disconnect from line 1 and prepare to prevent the bell from ringing while the terminal is making a call (Fig. 2 b, t ₂ ). Even if the telephone line 1 is in use, if the priority information indicates that priority is given to data communication, a similar terminal call is forcibly made. However, if the priority information indicates that calls are prioritized or calls and data communications are equal, the system waits until the call ends. When the telephone line 1 is not in use or data communication is prioritized, the automatic dialing circuit 11 further sends out a control signal c to close the switch circuit 14 and close the DC loop (FIG. 2 c, t ₃ ). A predetermined time after the DC loop is closed, the automatic dialing circuit 11 sends a call acceptance signal d to the terminal device 3 (d, t ₄ in FIG. 2). At the same time, the control signal e switches the switch circuit 10 from the signal line 22 side to the signal line 23 side again, and the automatic dial circuit 11 receives the data signal f from the terminal device 3 (FIG. 2, f, t ₄ ).
Further, the automatic dialing circuit 11 receives a call acceptance signal d.
and receives selected dial information sent as serial data from the terminal device 3 via the data signal line ₁₈₁ (FIG. 2 f, t ₅ ). After receiving this selection dial information, the switch circuit 10 is returned from the signal line 23 side to the signal line 22 side (e, t ₆ in FIG. 2), and the selection dial information is sent from the automatic dial circuit 11 after a predetermined time after the DC loop is closed. Sends a dial signal corresponding to For example, in the case of a dial pulse, it is sent out by opening and closing the switch circuit 14 in accordance with the control signal c (FIG. 2 c, t ₇ ). If there is no response from the center device within a predetermined time after the transmission of the selected dial information is completed, the switch circuit 14 is opened to open the DC loop, and the transmission of the call acceptance signal d to the terminal device 3 is stopped. . Further, after opening the DC loop, the switch circuit 7 is returned to the signal line 21 side after a predetermined guaranteed restoration time of the switching network has passed, and the telephone 2 is restored to the telephone line 1. After the terminal device 3 stops sending out the calling acceptance signal d, it stops sending out the calling request signal a and returns to the initial state. If there is a response from the center side device within a predetermined time after sending the selected dial information, the code sending circuit 9 sends out a response signal and enters a communicable state. At the same time, data transmission and reception is started between the center side device and the terminal device 3 via the data signal line ₁₈₁ by the data modulation/demodulation function of the code transmission circuit 9 (FIG. 2 f, t ₈ ). Here, when the telephone 2 is disconnected from the telephone line 1 and taken off-hook during communication, the off-hook detection circuit 15 detects the off-hook using the change in impedance of the telephone circuit. At this time,
If the priority information indicates that priority is given to calls, the switch circuit 14 is opened to open the DC loop, and after a predetermined guaranteed recovery time of the switching network has passed, the switch circuit 7 and the telephone 2 are restored and connected, and the sending of response signals is stopped. The transmission of the call acceptance signal d to the terminal device 3 is stopped and the use of the telephone 2 is prioritized. The center side device performs a recovery operation upon stopping the response signal. Upon stopping the call acceptance signal d, the terminal device 3 stops sending the call request signal a and restores to the initial state. However, if the priority information indicates that telephone calls and data communication systems are equal or that data communication is given priority, the line is switched after waiting until data transmission is completed. At the end of normal data communication, when the terminal device 3 stops sending the call request signal a, the network control device 5 opens the switch circuit 14 to open the DC loop, stops sending the response signal, and accepts the call. Stop sending signal d. (FIG. 2 a, c, d, t ₉ ) After the DC loop is opened, the switch circuit 7 and telephone 2 are restored and connected after a predetermined guaranteed restoration time of the switching network has elapsed (FIG. 2 b, t ₁₀ ). The center side device performs a recovery operation upon stopping the response signal. The control operation based on the priority information will be explained in more detail with reference to FIG. FIG. 3 is a block diagram of a main part of a control circuit provided in the automatic dialing circuit 11. Signal line 23 is connected to a serial-parallel code conversion and decoder latch circuit 25. This output j (call priority), k
(equivalent to telephone calls and data communications) and l (priority to data communications) are led to one input terminal of gate circuits 26 to 28, respectively. Further, the output of the line monitoring circuit 13 is led to the inverting input terminals of the gate circuits 26 and 27 and the other input terminal of the gate circuit 28, respectively. This gate circuit 26-2
The outputs of 8 are respectively led to input terminals of an OR circuit 29. The output of this OR circuit 29 is led to a set terminal of a flip-flop 30. The output of the flip-flop 30 is used as the control signal b for the switch circuit 7 and the control signal c for the switch circuit 14. Furthermore, the outputs j, k, l of the serial/parallel code conversion and decoding/latch circuit 25 are connected to the gate circuits 31 to 31.
33, respectively.
Further, the output of the off-hook detection circuit 15 is led to another input terminal of this gate circuit 31 and to the inverting input terminals of gate circuits 32 and 33, respectively. The outputs of the gate circuits 31 to 33 are respectively led to input terminals of an OR circuit 34. The output of this OR circuit 34 is led to the reset terminal of the flip-flop 30. Now, the serial/parallel code conversion and decoding latch circuit 25 converts the priority information of the serial code received from the terminal device 3 etc. through the signal line 23 into parallel codes, decodes them into three priority levels j, k, and l, and temporarily stores them. do. These outputs are connected to gate circuits 26 to 28.
Logic is determined between the output signal g and the output signal g indicating the use status of the telephone line 1 by the line monitoring circuit 13. Only when the data communication priority output 1 is set, the flip-flop 30 is set via the OR circuit 29 at the next stage even when the device is busy. Therefore, at this time, control signals b and c are output, switch circuits 7 and 14 operate, and the terminal is enabled to make a call. Next, during data communication, the off-hook detection circuit 15
When off-hook is detected by
The logic is taken. Only when the call priority output j is selected, the flip-flop 30 is reset via the OR circuit 34 at the next stage even during data communication. Therefore, at this time, the switch circuits 7 and 14 are restored by the control signals b and c, and priority is given to the use of telephone calls. Although the above embodiment shows the case where the priority information is received via the data signal line ₁₈₁ of the terminal device 3, the present invention is not limited to this, and other interface lines may be added. Furthermore, the information may be input directly to the automatic dialing circuit 11 from a strap setting device or the like instead of from the terminal device 3. In the above embodiment, the line monitoring circuit 13 first monitors the usage status of the telephone line 1 when making a call to the terminal, and then switches the telephone 2 to the telephone line only when the telephone line 1 is not in use or when data communication is prioritized. 1, after disconnecting the telephone 2 from the telephone line 1, the line monitoring circuit 13 monitors the usage status of the telephone line 1, and if the telephone line 1 is given priority to calls or calls and data communications are the same, the telephone line 1 is disconnected from the telephone line 1. If it is in use, the telephone 2 may be immediately restored to the telephone line 1. As described above, according to the present invention, when a telephone line intended for telephone calls is used for data communication, switching between telephone calls and data communication is performed in accordance with priority information provided from the outside. Therefore, even when making a call from a terminal, it is possible to perform data communication without any interference with the call, and moreover, through a no-ringing connection. In addition, the priority can be set according to the purpose of data collection for implementing the present invention, which has an excellent effect of allowing flexible use of telephone lines.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of essential parts of an embodiment of the present invention. FIG. 2 is an operation time chart showing the inputs or outputs at the points indicated by crosses in FIG. 1. FIG. 3 is a diagram showing an example of a control circuit for priority information. 1... Telephone line, 2... Telephone, 3, 4... Terminal device, 5... Network control device, 7, 10, 14...
Switch circuit, 8...Automatic incoming network control circuit, 9
... code transmission circuit, 11 ... automatic dialing circuit,
13...Line monitoring circuit, 15...Off-hook detection circuit, 18, 19...Cable, 21-23...
Signal lines, 26-28, 31-33...gate circuit, 29, 34...OR circuit, 30...flip-flop.

Claims (1)

[Claims] 1. A system located on the subscriber side of a subscriber's telephone line, configured so that a telephone or one or more terminal devices can be connected to the subscriber's telephone line, and in response to a call request from the terminal device, the subscriber's telephone In a network control device that transmits selected dial information to a line, establishes a connection with a center side device, and controls data communication between the terminal device and its center side device after the connection is completed, the terminal device means for giving priority information indicating the priority of using the telephone line according to information from the telephone line; and when the information giving priority to data communication is given from the means, the information is sent from the terminal device regardless of the usage state of the telephone line. When a call request signal is received, the telephone is disconnected from the telephone line to enable data communication, and when the telephone is given priority information from the above means, the off-hook of the telephone is detected, regardless of the state of use of the telephone line. 1. A network control device comprising: control means for connecting a telephone to a telephone line and controlling the telephone to enable communication.