JP4212310B2 - Terminal side network controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides an automatic data communication system that performs data communication by calling a terminal from a terminal device using a telephone line, and performs data communication by using a no-ringing trunk upon activation from a center side network control device . The present invention relates to a terminal side network control device when coexisting with an ADSL communication service.
[0002]
[Prior art]
There is a no-ringing service that performs automatic meter reading of electricity, water, gas, etc. without ringing the phone line. Generally, when a terminal side network control unit (T-NCU) is activated from a host device, a no ringing call signal (NRS) is issued from a no ringing trunk by a dial signal of the center side network control unit (C-NCU). If the signal matches the activation signal of the T-NCU itself, the T-NCU sends an NR (no ringing) response signal “#”. At this time, there are cases where ADSL (Asymmetric Digital Subscriber Line) equipment (splitter, ADSL modem, etc.), telephone, etc. are connected to the subsequent stage of the T-NCU in addition to meter / sensors such as electricity, water, gas, etc. is there.
[0003]
[Problems to be solved by the invention]
However, the input impedance from the line side of the splitter connected to the subsequent stage of the T-NCU has a resonance point in the frequency range of 1 to 3 kHz, and 100 Ω with respect to the AC impedance 600Ω of the telephone line at the resonance point. Low impedance before and after. For this reason, the NR response signal “#” transmitted from the T-NCU is attenuated such that the levels of the low group frequency and the high group frequency are reversed, and the no ringing (NR) trunk receives the NR response signal “#”. The T-NCU cannot communicate because the line cannot be connected, or the communication signal between the C-NCU and the T-NCU is attenuated and communication is not possible.
[0004]
As a comparative example, Japanese Patent Laid-Open No. 4-326651 discloses an automatic data communication system using a subscriber telephone line in which a facsimile machine (FAX) harmful to no-ringing communication is connected downstream of the T-NCU. A terminal network control device is disclosed that disconnects a FAX from a T-NCU when a main control unit of the T-NCU detects an NRS and determines that the terminal is a local terminal. According to this, even if the NRS component includes a signal similar to the FAX activation signal, the FAX does not respond erroneously. Therefore, the T-NCU communication is not hindered by an erroneous FAX response.
[0005]
Japanese Patent Laid-Open No. 3-11870 discloses that when the first terminal device is activated from another transmission device via a communication line, the second terminal device is communicated so that the second terminal device does not malfunction. A data transmission device is disclosed that is disconnected from a line.
[0006]
However, none of the above publications describes a case where an ADSL device such as a splitter is connected.
[0007]
In view of the above problems, an object of the present invention is to provide a terminal-side network control device in which communication is not disturbed even by connection of an ADSL device.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the terminal-side network control device of the present invention uses a telephone line to perform data communication by calling a terminal from the terminal device, and starts up a no-ringing trunk when activated from the center-side network control device. In an automatic data communication system that performs data communication using a terminal, it is a terminal-side network control device when coexisting with an ADSL communication service, and a no-ringing call signal sent from the center-side network control device via the no-ringing trunk is A main control unit that determines whether or not the signal is to be transmitted to the own terminal, and that determines that the no-ringing call signal is a signal to the own terminal; and after transmitting the no-ringing response signal, the no-ringing A trunk recognizes the no ringing response signal, and a link is established with the center side network control device, When a data communication signal to be sent from the center side network control device is not detected, a counter for adding the number of voice communication failures, and when the value of the counter reaches a predetermined value, from the next center side network control device Connection switching that disconnects communication equipment such as telephones that include ADSL splitters connected to the subsequent stage of the terminal-side network controller before sending a no-ringing response signal after determining that the no-ringing call signal due to the activation of the terminal is a signal to the terminal itself And a circuit.
[0012]
The reconnection of the device may be performed after the next no-ringing response signal is transmitted, or after the next no-ringing response signal is transmitted, the data communication with the C-NCU is performed and the data communication is completed. Good.
[0013]
According to this configuration, by changing the predetermined value, it is determined that the NRS signal cannot be communicated due to other factors and the NRS signal is determined as the local terminal, and the NR response signal is not disconnected without disconnecting the device connected to the subsequent stage. , And then the cause of the failure to detect the communication signal from the C-NCU in communication with the host device can be specified, and the system can be operated more reliably.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a configuration of an automatic data communication system. Reference numeral 10 denotes a center-side host device, 11 denotes a center-side network control device (C-NCU) that transmits and receives signals by connecting the host device 10 and a telephone line 12, and 13 denotes a center connected to the C-NCU 11. 14 is a terminal-side switching center connected to the terminal side, 15 is a no-ringing (NR) trunk that controls so as to make a no-ringing call without ringing the terminal-side telephone or the like, 16 is an ADSL management function, etc. DSLAM (Digital Subscriber Line Access Multiplexer) 17 supporting the network is a network.
[0015]
Reference numeral 18 denotes a distribution mixer that distributes or mixes low and high frequencies, 19 is a splitter that separates / combines analog audio signals and ADSL signals, 20 is an ADSL modem that modulates / demodulates data, and 21. Is a personal computer (PC), 22 is a communication equipment of POTS (Plain Old Telephone Service) such as a telephone or FAX, 23 is a terminal side network control unit (T-NCU), and 24 is a meter for electricity, water, gas, etc. .
[0016]
FIG. 2 is a block diagram showing a configuration of the T-NCU 23 and peripheral devices. Reference numeral 30 is a polar detection circuit for detecting that the NR trunk 15 has reversed the polarity of the telephone line, 31 is a communication circuit having a modem function, and 32 is the presence / absence of use of the communication device 22 during communication of the T-NCU 23. , An off-hook detection circuit 33, a meter interface circuit for connecting the T-NCU 23 and the meter 24, a connection switching circuit 34 for switching connection / disconnection of a downstream device including a splitter, and a microcomputer 35 for controlling the T-NCU And the like. The main control unit 35 is also provided with a RAM 35a for storing the NRS number of the terminal itself and a counter 35b for adding a numerical value when a communication signal such as an FSK signal cannot be received after the start of communication. The switching operation of the connection switching circuit 34 can also be set by a user using a command.
[0017]
Here, the operation of the T-NCU will be described. When there is an NR incoming call from the center side network control device 11, the polar reversal detection circuit 30 first detects the polarity inversion. Next, main controller 35 switches from the standby mode to the NRS detection operation mode. When the communication circuit 31 detects the NRS, the main control unit 35 transmits an NR response signal in response thereto. As a result, a communication link with the host apparatus 10 is established, and data communication is started in an asynchronous manner.
[0018]
FIG. 3 is a block diagram showing the configuration of the distribution mixer 18. Reference numeral 40 denotes a low-pass filter L that connects the telephone line 12 and the T-NCU 23 and passes only an analog audio signal. Reference numeral 41 denotes a low-pass filter T that connects the T-NCU 23 and the splitter 19; Is a high pass filter.
[0019]
Of the signals input from the telephone line, the ADSL signal passes through the high-pass filter 42, and the analog voice signal passes through the low-pass filter L 40, T-NCU 23, and the low-pass filter T 41, and is mixed. Is input.
[0020]
Next, the operation of the T-NCU 23 in which communication is not hindered by connection of ADSL equipment will be described. FIG. 4 is a flowchart showing the operation of the T-NCU 23. First, when there is an NR incoming call from the C-NCU 11 in step S10, the polar reversal detection circuit 30 detects polarity reversal. As a result, an extremely interrupt signal is generated, and the process proceeds to step S11 where the main control unit 35 switches from the standby mode to the NRS detection mode. In step S12, the communication circuit 31 is controlled to the NRS detection mode, and the NRS transmitted from the NR trunk 15 for about 1 second is detected. Proceeding from step S12 to step S13, it is determined whether the NRS is equal to or greater than 20 ms. When the NRS is 20 ms or more in step S13, the process proceeds to step S14 to determine whether or not it matches the NRS number stored in the RAM 35a. If they do not match in step S14, the process returns to the standby mode.
[0021]
On the other hand, if they match in step S14, it is determined that the terminal is the terminal itself, and the process proceeds to step S15 to check the RAM 35a to see if the command is 0 or not. In the RAM 35a, the command is 1 when the splitter 19 harmful to the NR communication is connected in advance, the command is 2 when there is a possibility that the main line will become ADSL in the future, and the command is 0 in other cases. Is set. Command 0 represents the process of sending the NR response signal without disconnecting the subsequent stage device, and Command 1 represents the process of disconnecting the subsequent stage device before sending the NR response signal and reconnecting the subsequent stage device after sending the NR response signal. , Command 2 represents a process in which the subsequent device is disconnected before sending the NR response signal, and the reconnection of the subsequent device is not performed until the end of communication. The initial value of the command is 0, and the command is determined to be 0 in the first step S15. A case where the initial value of the command is 1 is also conceivable. In this case, if communication fails and the counter reaches a predetermined value or more, command 2 is set. The user can change to command 0 by changing the setting.
[0022]
When the command is 1 or 2 in step S15, the process proceeds to step S16, the connection switching circuit 34 is driven to disconnect the subsequent device of the T-NCU 23, and then the process proceeds to step S17. On the other hand, when the command is 0 in step S15, the process proceeds to step S17, where it is confirmed that the NRS has been interrupted, and an NR response signal “#” is transmitted after a predetermined time.
[0023]
After completing the transmission of the NR response signal, the process proceeds to step S18 to determine whether the command is 0 or 2. When the command is 1 in step S18, the process proceeds to step S19 to reconnect the subsequent device, and then proceeds to step S20. On the other hand, when the command is 0 or 2 in step S18, the process proceeds to step S20 to start communication. Specifically, it enters a standby state for an FSK (Frequency Shift Keying) signal.
[0024]
Proceeding from step S20 to step S21, it is determined whether or not a communication signal such as an FSK signal has been received. If a communication signal such as an FSK signal has not been received in step S21, it is determined that the NR response signal “#” has not reached the no-ringing trunk 15 and the line has not been connected, and the process proceeds to step S22 to proceed to the counter 35b. 1 is added to the value of. Next, it progresses from step S22 to step S23, and it is discriminate | determined whether the value of the counter 35b became more than predetermined value (for example, 3).
[0025]
If the value of the counter 35b is equal to or larger than the predetermined value in step S23, the process proceeds to step S24 and the command is set to 1 or 2. And it progresses to step S25 from step S24, a terminal call flag is set, and it returns to standby mode. On the other hand, if the value of the counter 35b is less than the predetermined value in step S23, the process returns to the standby mode.
[0026]
On the other hand, if a communication signal such as an FSK signal is received in step S21, the process proceeds to step S26 to clear the value of the counter 35b, and then proceeds to step S27 to continue communication. After that, when communication is completed, it returns to the standby mode.
[0027]
As described above, if the counter 35b is equal to or greater than the predetermined value, the process proceeds from step S15 to step S16 next time, and the subsequent device of the T-NCU 23 is disconnected. Here, “next time” may be set once and return to the initial condition thereafter, or may be fixed after the next time.
[0028]
In this way, when a device harmful to NR communication is connected to the subsequent stage of the T-NCU 23, disconnecting the subsequent apparatus before sending out the NR response signal results in an incommunicable state due to signal attenuation or the like. Can be avoided.
[0029]
When the process proceeds to step S15 after the elapse of step S24, since the command is not 0, the process proceeds from step S15 to step S16, the subsequent device is disconnected, and more reliable NR communication is possible. Therefore, the user himself / herself does not need to set commands, and the system can be operated more simply and efficiently.
[0030]
Further, since the T-NCU 23 makes a terminal call and notifies the C-NCU 11 by the terminal call flag in step S25, the system operator can more reliably grasp the operation status of the T-NCU 23. Reliable system management is possible. Further, the value of the counter 35b and the predetermined value can be set and read by the user. Therefore, by changing this predetermined value, it is determined that the NRS signal is the local terminal without being able to communicate due to other factors, and the NR response signal “#” is disconnected without disconnecting the device connected in the subsequent stage. ”And then the reason why the communication signal from the C-NCU 11 cannot be detected in communication with the host device 10 can be specified, and the system can be operated more reliably.
[0031]
In the above-described embodiment, after the transmission of the NR response signal, the subsequent device is reconnected in step S19. Instead, the subsequent device is reconnected after the communication in step S27 is completed. Good. As a result, it is possible to more reliably avoid communication interference caused by subsequent devices not only when the NR response signal is transmitted but also during data communication.
[0032]
In the above embodiment, the commands 0 to 2 of the RAM 35a and the counter 35b are not provided. If the NRS numbers match in step S14, the device connected to the subsequent stage is disconnected, and the NR response signal is transmitted. May be reconnected and communication may be continued. At this time, reconnection of a subsequent device may be performed after communication is completed. Thus, by disconnecting the subsequent device before sending out the NR response signal, it is possible to eliminate the signal attenuation caused by the device harmful to the NR communication, and to avoid a state incapable of communication.
[0033]
Next, the operation of the automatic data communication system when the communication device 22 is used during data communication between the T-NCU 23 and the C-NCU 11 will be described. When the command in the RAM 35a is 0 or 1, the device connected in the subsequent stage is connected by the connection switching circuit 34 during data communication, and the NR trunk 15 detects an off-hook when the communication device 22 is used. To do. In response to this, the NR communication (data communication) is interrupted, and the communication device 22 can be used.
[0034]
On the other hand, when the command is 2, the device connected in the subsequent stage is disconnected by the connection switching circuit 34 during data communication, and when the communication device 22 is used, the off-hook detection circuit 32 detects off-hook. Then, the main control unit 35 determines that it is off-hook, and drives the connection switching circuit 34 to reconnect the subsequent device. In response to this, the NR trunk 15 detects off-hook, NR communication (data communication) is interrupted, and the communication device 22 can be used.
[0035]
As described above, when the command of the RAM 35a is 0 to 2, the use of the communication device 22 is prioritized. However, the command 3 that prioritizes data communication may be additionally set. Here, the command 3 conforms to the operation when the command is 2, and when the device connected in the subsequent stage is off-hooked while the T-NCU 23 is performing data communication, the main control unit 35 ignores the off-hook and sets the T This command is executed with priority until the data communication of the NCU 23 is completed.
[0036]
【The invention's effect】
According to the present invention, when a device harmful to NR communication is connected to the subsequent stage of the terminal-side network control device, communication cannot be performed due to signal attenuation or the like by disconnecting the subsequent stage device before sending the NR response signal. Can be avoided.
[0037]
Further, according to the present invention, by changing the predetermined value of the counter, it is determined that the NRS signal is the own terminal, eliminating the fact that communication has failed due to other factors, and do not disconnect the device connected to the subsequent stage. An NR response signal is transmitted, and then the cause of the failure to detect the communication signal from the center side network control device in communication with the host device can be specified, and the system can be operated more reliably.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an automatic data communication system including a terminal-side network control device according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of a terminal-side network control device and peripheral devices according to the present invention.
FIG. 3 is a block diagram showing a configuration of the distribution mixer of FIG. 1;
FIG. 4 is a flowchart showing the operation of the terminal-side network control device of the present invention.
[Explanation of symbols]
11 Center side network control device 15 No ringing trunk 21 PC (terminal device)
23 Terminal-side network control device 32 Off-hook detection circuit 34 Connection switching circuit 35 Main control unit 35b Counter

Claims (6)

By using a telephone line, performs data communication by the terminal call from the terminal device, also Oite automatic data communication system using a non-ringing trunk start from the center-side network controller perform data communication, ADSL communication A terminal-side network control device for coexisting with a service,
It is determined whether or not a no ringing call signal sent from the center side network control device via the no ringing trunk is a signal to the own terminal, and when it is determined that the no ringing call signal is a signal to the own terminal, no ringing is performed. A main control unit for sending a response signal;
After sending the no-ringing response signal, the no-ringing trunk recognizes the no-ringing response signal, establishes a link with the center-side network control device, and no data communication signal to be sent from the center-side network control device is detected. In this case, a counter for adding the number of voice communication failures, and when the counter value reaches a predetermined value, it is determined that a no ringing call signal by the next activation from the center side network control device is a signal to the own terminal. A connection switching circuit for disconnecting a communication device such as a telephone set including an ADSL splitter connected to a subsequent stage of the terminal-side network control device before sending a response signal and reconnecting the communication device after sending a no-ringing response signal A terminal-side network controller characterized by the above. By using a telephone line, performs data communication by the terminal call from the terminal device, also Oite automatic data communication system using a non-ringing trunk start from the center-side network controller perform data communication, ADSL communication A terminal-side network control device for coexisting with a service,
It is determined whether or not a no ringing call signal sent from the center side network control device via the no ringing trunk is a signal to the own terminal, and when it is determined that the no ringing call signal is a signal to the own terminal, no ringing is performed. A main control unit for sending a response signal;
After sending the no-ringing response signal, the no-ringing trunk recognizes the no-ringing response signal, establishes a link with the center-side network control device, and no data communication signal to be sent from the center-side network control device is detected. In this case, a counter for adding the number of voice communication failures, and when the counter value reaches a predetermined value, it is determined that a no ringing call signal by the next activation from the center side network control device is a signal to the own terminal. Before transmitting the response signal, disconnect the communication device such as the telephone including the ADSL splitter connected to the subsequent stage of the terminal side network control device, and after transmitting the no ringing response signal, the telephone including the ADSL splitter connected to the subsequent stage Data communication with the center side network control device is maintained while maintaining the disconnection of communication equipment such as , The terminal-side network control apparatus characterized by comprising a connection switching circuit to reconnect the communication device after the communication completes. The operation of the connection switching circuit can be set by a command. 1 Or 2 The terminal-side network control device described. An off-hook detection circuit for detecting an off-hook of the communication device is provided, and when the off-hook is detected during the data communication, the data communication is temporarily interrupted and the communication device is reconnected. 2 The terminal-side network control device described. The counter value and the predetermined value can be set and read by a user. 1 Or 2 The terminal-side network control device described. The center side network control device is notified by a terminal call when the value of the counter reaches a predetermined value. 1 Or 2 The terminal-side network control device described.

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