Link detection circuit, method, device and medium in dedicated line communication process

Abstract

The present invention relates to the technical field of wired modem communications, and more specifically to a link detection circuit, method, device, and medium for dedicated line communications. These circuits can distinguish between normal communication and disconnection in a two-line dedicated line, and can also distinguish between normal communication and disconnection in a four-line dedicated line, when the modem module chip cannot automatically detect a telephone line disconnection. This allows for rapid detection of disconnection events in dedicated line communications. The present invention only requires determining whether the DETECT1 and DETECT2 signals have changed to determine whether the dedicated line link is disconnected. The circuit is simple, the performance is reliable, and the disconnection event can be rapidly detected in dedicated line communications.

Description

Technical Field

[0001] This invention relates to the field of wired modem communication technology, specifically to a link detection circuit, method, device, and medium in a leased line communication process. Background Technology

[0002] The physical link for wired modem communication can be the public telephone network (PTN) or a dedicated 2-wire or 4-wire leased line. Both transmit modulated signals when using telephone lines and leased lines; the difference is that telephone lines have a power supply voltage, while leased lines do not. Timely detection of abnormal link breaks is crucial during communication. Modem module chips are suitable for the PTN and support modulation protocols such as V.92, V.90, V.34, V.32, V.23, V.22, and V.21. They can automatically detect telephone line breaks during communication.

[0003] In some application scenarios, to support 2 / 4-wire leased line communication, a leased line to telephone line module needs to be added. This module maintains a constant connection with the modem module chip, so when the leased line connection is lost, the modem module chip can no longer detect the break. Furthermore, leased line communication has two scenarios: 2-wire and 4-wire. Both 2-wire and 4-wire leased lines present the problem of indistinguishable communication and disconnection states.

[0004] It is evident that if a module and the modem module chip remain connected, the modem module chip cannot automatically detect a broken link in the telephone line. Therefore, a link detection technology is needed in the leased line communication process to quickly detect broken link events in 2-wire and 4-wire leased line communication. Summary of the Invention

[0005] In view of this, the present invention provides a link detection circuit, method, device and medium in the process of leased line communication, which can distinguish between the normal communication state and the disconnection state of a 2-line leased line when the modem module chip cannot automatically detect the telephone line disconnection, and can also distinguish between the normal communication state and the disconnection state of a 4-line leased line, and quickly detect the disconnection event in leased line communication.

[0006] To achieve the above objectives, this invention provides a link detection circuit in a leased line communication process, including a 4-wire leased line detection circuit and a 2-wire leased line detection circuit. The 4-wire leased line detection circuit includes a first inverting follower circuit and a first comparator circuit. The first inverting follower circuit introduces the signal received at the RX terminal into the comparator circuit. The first comparator circuit is used to detect changes in the signal received at the RX terminal, and the result is output to the output pin of the operational amplifier in the first comparator circuit, denoted as the DETECT1 signal. The 2-wire leased line detection circuit includes a second inverting follower circuit, a third inverting follower circuit, and a second comparator circuit. The second inverting follower circuit inverts the signal received at the RX terminal and introduces it into the comparator circuit. The third inverting follower circuit inverts the local TX signal and introduces it into the second comparator circuit. The second comparator circuit is used to detect the comparison between the signal received at the RX terminal and the local TX signal, and the result is output to the output pin of the operational amplifier in the second comparator circuit, denoted as the DETECT2 signal. The leased line link is determined to be disconnected based on whether the DETECT1 and DETECT2 signals change.

[0007] In this circuit, resistors R12 and R13, along with the first operational amplifier, constitute the first inverting follower circuit; resistors R14, R15, and R16, along with the second operational amplifier, constitute the first comparator circuit. The signal received at the RX terminal passes through resistor R12 and is connected to the inverting input of the first operational amplifier; the VREF reference voltage passes through resistor R13 and is connected to the non-inverting input of the first operational amplifier; and the feedback resistor R11 is connected between the output pin and the inverting input of the first operational amplifier. The inverted signal received at the RX terminal passes through resistor R14 and is connected to the inverting input of the second operational amplifier; the VREF reference voltage passes through resistor R15 and is connected to the non-inverting input of the second operational amplifier; and the feedback resistor R16 is connected between the output pin and the non-inverting input of the second operational amplifier.

[0008] Among them, the values ​​of resistors R11, R12 and R13 are in the range of 5KΩ to 10KΩ; the values ​​of resistors R14 and R15 are in the range of 5KΩ to 10KΩ; and the value of resistor R16 is 80 to 100 times that of R15.

[0009] In this circuit, resistors R1, R2, and R3, along with the third operational amplifier, constitute the second inverting follower circuit; resistors R5, R6, and R7, along with the fourth operational amplifier, constitute the third inverting follower circuit; and resistors R4, R8, and R9, along with the fifth operational amplifier, constitute the second comparator circuit. The signal received at the RX terminal is connected to the inverting input of the third operational amplifier via resistor R2, the VREF reference voltage is connected to the non-inverting input of the third operational amplifier via resistor R3, and the feedback resistor R1 is connected between the output pin and the inverting input of the first operational amplifier. The local TX signal is connected to the inverting input of the fourth operational amplifier via resistor R6, the VREF reference voltage is connected to the non-inverting input of the fourth operational amplifier via resistor R7, and the feedback resistor R5 is connected between the output pin and the non-inverting input of the fourth operational amplifier. The inverted signal received at the RX terminal is connected to the inverting input of the fifth operational amplifier via resistor R4, the inverted local TX signal is connected to the non-inverting input of the fifth operational amplifier via resistor R8, and the feedback resistor R9 is connected between the output pin and the non-inverting input of the fifth operational amplifier.

[0010] Among them, the values ​​of resistors R1, R2, R3, R5, R6 and R7 are in the range of 5KΩ to 10KΩ; the values ​​of resistors R4 and R8 are in the range of 5KΩ to 10KΩ; and the value of resistor R9 is 80 to 100 times that of R8.

[0011] The continuous switching of the DETECT1 and DETECT2 signals indicates that the corresponding link is normal, while the unchanged DETECT1 and DETECT2 signals indicate that the corresponding link is disconnected.

[0012] The 4-line dedicated line detection circuit and the 2-line dedicated line detection circuit are implemented using 3 dual operational amplifiers or 5 single operational amplifiers.

[0013] This invention also provides a link detection method in leased line communication, comprising the following steps:

[0014] Construct the 4-wire dedicated line detection circuit and the 2-wire dedicated line detection circuit described in this invention;

[0015] The RX end receives signals;

[0016] Detect whether the DETECT1 and DETECT2 signals change; if the DETECT1 and DETECT2 signals change continuously, it indicates that the corresponding link is normal; if the DETECT1 and DETECT2 signals remain unchanged, it indicates that the corresponding link is disconnected.

[0017] The present invention also provides an electronic device, the electronic device including a processor and a memory for storing executable instructions of the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the link detection method in the leased line communication process described in the present invention.

[0018] The present invention also provides a computer-readable storage medium storing a computer program for executing the link detection method in the leased line communication process described in the present invention.

[0019] Beneficial effects:

[0020] 1. The circuit of this invention can distinguish between normal communication and disconnection states of a 2-wire leased line, and also between normal communication and disconnection states of a 4-wire leased line. It only requires checking whether the DETECT1 and DETECT2 signals change to determine if the leased line link is broken. The circuit is simple, reliable, and can quickly detect disconnection events in leased line communication.

[0021] 2. In the 4-wire dedicated line detection circuit of the present invention, resistors R11, R12, R13 and operational amplifier U3B constitute an inverting follower circuit, which introduces the signal received at the RX terminal into the next stage detection circuit, while reducing the influence on the original signal received at the RX terminal.

[0022] 3. In the 2-line dedicated line detection circuit of the present invention, resistors R1, R2, R3 and operational amplifier U1B constitute an inverting follower circuit, which inverts the signal received at the RX terminal and introduces it into the next stage detection circuit, while reducing the influence on the original signal received at the RX terminal; resistors R5, R6, R7 and operational amplifier U2B constitute an inverting follower circuit, which inverts the TX signal and introduces it into the next stage detection circuit, while reducing the influence on the original TX signal.

[0023] 4. The detection method of the present invention is based on the detection circuit of the present invention. It only needs to determine whether the DETECT1 and DETECT2 signals change to determine whether the leased line link is disconnected. The continuous switching of the DETECT1 and DETECT2 signals indicates that the link is normal, while the DETECT1 and DETECT2 signals remain unchanged to indicate that the link is disconnected. With a simple and practical method, it is possible to detect whether the leased line communication link is disconnected.

[0024] 5. The device of this invention is used to implement the detection method of this invention. It can distinguish between normal communication status and disconnection status of a 2-line leased line, and also between normal communication status and disconnection status of a 4-line leased line. It only requires determining whether the DETECT1 and DETECT2 signals change to determine if the leased line link is broken. The circuit is simple, the performance is reliable, and it can quickly detect disconnection events in leased line communication.

[0025] 6. The medium of this invention is used to implement the detection method of this invention, distinguishing between normal communication status and disconnection status of a 2-line leased line, and also between normal communication status and disconnection status of a 4-line leased line. It only requires judging whether the DETECT1 and DETECT2 signals change to determine whether the leased line link is broken. The circuit is simple, the performance is reliable, and it can quickly detect disconnection events in leased line communication. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the 4-line dedicated line detection circuit of the present invention.

[0027] Figure 2 This is a schematic diagram of the 2-line dedicated line detection circuit of the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] This invention provides a link detection circuit in the process of leased line communication, including a 4-wire leased line detection circuit and a 2-wire leased line detection circuit.

[0031] 4-wire dedicated line detection circuit, such as Figure 1 As shown, resistors R11, R12, and R13, along with the first operational amplifier U3B, form an inverting follower circuit. This circuit introduces the signal received at the RX terminal into the next stage detection circuit, i.e., the comparator circuit, while simultaneously reducing the impact on the original signal received at the RX terminal. Resistors R14, R15, and R16, along with the second operational amplifier U3A, form a comparator circuit that detects changes in the signal received at the RX terminal. The result is output to the output pin (U3A-PIN1) of the second operational amplifier, denoted as the DETECT1 signal. For a 4-wire leased line, during normal communication, the RX terminal receives the TX signal from the other party. This signal is sometimes larger than VREF (reference voltage) and sometimes smaller than VREF, so the DETECT1 signal is a constantly fluctuating signal. When the link is broken, the RX terminal does not receive the TX signal from the other party. This signal is either larger or smaller than VREF, so the DETECT1 signal remains a constant high or low level.

[0032] Specifically, in this embodiment, the signal received at the RX terminal is connected to the inverting input terminal (operational amplifier U3B-PIN6) of the first operational amplifier via resistor R12, the VREF reference voltage via resistor R13 is connected to the non-inverting input terminal (operational amplifier U3B-PIN5) of the first operational amplifier, and the feedback resistor R11 is connected between the output terminal (operational amplifier U3B-PIN7) and the inverting input terminal (operational amplifier U3B-PIN6) of the first operational amplifier; the signal received at the inverted RX terminal is connected to the inverting input terminal (U3A-PIN2) of the second operational amplifier via resistor R14, the VREF via resistor R15 is connected to the non-inverting input terminal (U3A-PIN3) of the second operational amplifier, and the feedback resistor R16 is connected between the output terminal (U3A-PIN1) and the non-inverting input terminal (U3A-PIN3) of the second operational amplifier.

[0033] Among them, the values ​​of resistors R11, R12 and R13 are in the range of 5KΩ to 10KΩ; the values ​​of resistors R14 and R15 are in the range of 5KΩ to 10KΩ; and the value of resistor R16 is 80 to 100 times that of R15.

[0034] 2-line dedicated line detection circuit, such as Figure 2 As shown, resistors R1, R2, and R3, along with the third operational amplifier U1B, form an inverting follower circuit. This circuit inverts the signal received at the RX terminal and introduces it into the next-stage detection circuit, i.e., the comparator circuit, while simultaneously reducing the impact on the original signal received at the RX terminal. Resistors R5, R6, and R7, along with the fourth operational amplifier U2B, also form an inverting follower circuit. This circuit inverts the local TX signal and introduces it into the next-stage detection circuit, again reducing the impact on the original local TX signal. Resistors R4, R8, and R9, along with the fifth operational amplifier U1A, form a comparator circuit. This circuit detects the comparison between the signal received at the RX terminal and the local TX signal, and the result is output to the output pin (U1A-PIN1) of the fifth operational amplifier, denoted as the DETECT2 signal. For a two-wire leased line, during normal communication, the RX terminal receives both the other party's TX signal and the local TX signal. The DETECT2 signal is a constantly changing signal that changes with the change in the other party's TX signal. When the link is broken, the RX terminal does not receive the other party's TX signal, but it will receive the local TX signal. The DETECT2 signal will then remain at a constant high or low level.

[0035] Specifically, in this embodiment, the signal received at the RX terminal is connected to the inverting input terminal of the third operational amplifier (operational amplifier U1B-PIN6) via resistor R2, the VREF reference voltage via resistor R3 is connected to the non-inverting input terminal of the third operational amplifier (operational amplifier U1B-PIN5), and the feedback resistor R1 is connected between the output pin (operational amplifier U1B-PIN7) and the inverting input terminal (operational amplifier U1B-PIN6) of the first operational amplifier; the local TX signal via resistor R6 is connected to the inverting input terminal (U2B-PIN6) of the fourth operational amplifier, and the VREF via resistor R7 is connected to the... The non-inverting input (U2B-PIN5) of the fourth operational amplifier is connected to the output pin (U2B-PIN7) and the non-inverting input (U2B-PIN6) of the fourth operational amplifier. The signal received by the inverted RX pin is connected to the inverting input (U1A-PIN2) of the fifth operational amplifier via resistor R4. The local TX signal after inversion is connected to the non-inverting input (U1A-PIN3) of the fifth operational amplifier via resistor R8. The feedback resistor R9 is connected between the output pin (U1A-PIN1) and the non-inverting input (U1A-PIN3) of the fifth operational amplifier.

[0036] In summary, the status of a leased line link can be determined by whether the DETECT1 and DETECT2 signals change. Specifically, if the DETECT1 and DETECT2 signals change continuously, it indicates that the corresponding link is normal, while if the DETECT1 and DETECT2 signals remain unchanged, it indicates that the corresponding link is disconnected.

[0037] Among them, the values ​​of resistors R1, R2, R3, R5, R6 and R7 are in the range of 5KΩ to 10KΩ; the values ​​of resistors R4 and R8 are in the range of 5KΩ to 10KΩ; and the value of resistor R9 is 80 to 100 times that of R8.

[0038] Furthermore, the 4-line dedicated line detection circuit and the 2-line dedicated line detection circuit of the present invention can be implemented using 3 dual operational amplifiers or 5 single operational amplifiers.

[0039] This invention also provides a link detection method in leased line communication, implemented based on the circuit of this invention, comprising the following steps:

[0040] Construct the 4-wire dedicated line detection circuit and the 2-wire dedicated line detection circuit described in this invention;

[0041] The RX end receives signals;

[0042] Detect whether the DETECT1 and DETECT2 signals change; if the DETECT1 and DETECT2 signals change continuously, it indicates that the corresponding link is normal; if the DETECT1 and DETECT2 signals remain unchanged, it indicates that the corresponding link is disconnected.

[0043] This application also provides an electronic device. Figure 3 The structure of an electronic device provided in an embodiment of the present invention is illustrated. For example, the electronic device 30 may include a processor 31, a memory 32, and a transmission device 33. The processor 31 is used to execute the link detection method in the leased-line communication process mentioned in the above embodiments. The processor and the memory can be connected via a bus or other means, taking a bus connection as an example. The transmission device can be connected to the processor and the memory via wired or wireless means. The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the link detection method in the leased-line communication process in the embodiments of this application. The processor executes various functional applications and data processing by running the non-transitory software programs, instructions, and modules stored in the memory, thereby implementing the link detection method in the leased-line communication process in the above method embodiments. The memory may include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created by the processor, etc. In addition, the memory may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, and this remote memory may be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The one or more modules stored in the memory, when executed by the processor, perform the link detection method in the leased-line communication process of the embodiments.

[0044] In another aspect, this application also provides a computer-readable storage medium, which may be the computer-readable storage medium included in the apparatus described in the above embodiments; or it may be a standalone computer-readable storage medium not assembled into the device. The computer-readable storage medium may be a tangible storage medium, such as random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, floppy disk, hard disk, removable storage disk, CD-ROM, or any other form of storage medium known in the art. The computer-readable storage medium stores one or more programs, which are used by one or more processors to execute the link detection method described in the leased-line communication process of this application.

[0045] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A link detection circuit in a leased line communication process, characterized in that, The system includes a 4-wire dedicated line detection circuit and a 2-wire dedicated line detection circuit. The 4-wire dedicated line detection circuit includes a first inverting follower circuit and a first comparator circuit. The first inverting follower circuit introduces the signal received at the RX terminal into the comparator circuit, which detects changes in the signal received at the RX terminal. The result is output to the output pin of the operational amplifier in the first comparator circuit, denoted as the DETECT1 signal. The 2-wire dedicated line detection circuit includes a second inverting follower circuit, a third inverting follower circuit, and a second comparator circuit. The second inverting follower circuit inverts the signal received at the RX terminal and introduces it into the comparator circuit. The third inverting follower circuit inverts the local TX signal and introduces it into the second comparator circuit. The second comparator circuit detects the comparison between the signal received at the RX terminal and the local TX signal, and the result is output to the second comparator circuit. The output pin of the operational amplifier is denoted as the DETECT2 signal. The presence or absence of changes in the DETECT1 and DETECT2 signals determines whether the leased line link is disconnected. For a 4-wire leased line, during normal communication, the RX end receives the TX signal from the other party, and the DETECT1 signal is a constantly changing signal. When the link is disconnected, the RX end does not receive the TX signal from the other party, and the DETECT1 signal remains constant at a high or low level. For a 2-wire leased line, during normal communication, the RX end receives both the TX signal from the other party and the local TX signal. The DETECT2 signal is a constantly changing signal that changes with the TX signal from the other party. When the link is disconnected, the RX end does not receive the TX signal from the other party, but it will receive the local TX signal, and the DETECT2 signal remains constant at a high or low level. Resistors R12 and R13, along with the first operational amplifier, constitute a first inverting follower circuit. Resistors R14, R15, and R16, along with the second operational amplifier, constitute a first comparator circuit. The signal received at the RX terminal passes through resistor R12 and is connected to the inverting input of the first operational amplifier. The VREF reference voltage passes through resistor R13 and is connected to the non-inverting input of the first operational amplifier. Feedback resistor R11 is connected between the output pin and the inverting input of the first operational amplifier. The inverted signal received at the RX terminal passes through resistor R14 and is connected to the inverting input of the second operational amplifier. VREF passes through resistor R15 and is connected to the non-inverting input of the second operational amplifier. Feedback resistor R16 is connected between the output pin and the non-inverting input of the second operational amplifier. Resistors R1, R2, and R3, along with the third operational amplifier, constitute a second inverting follower circuit. Resistors R5, R6, and R7, along with the fourth operational amplifier... The circuit consists of a third inverting follower circuit; resistors R4, R8, and R9, along with the fifth operational amplifier, form the second comparator circuit; the signal received at the RX terminal is connected to the inverting input of the third operational amplifier via resistor R2, the VREF reference voltage is connected to the non-inverting input of the third operational amplifier via resistor R3, and the feedback resistor R1 is connected between the output pin and the inverting input of the first operational amplifier; the local TX signal is connected to the inverting input of the fourth operational amplifier via resistor R6, the VREF reference voltage is connected to the non-inverting input of the fourth operational amplifier via resistor R7, and the feedback resistor R5 is connected between the output pin and the non-inverting input of the fourth operational amplifier; the signal received at the inverted RX terminal is connected to the inverting input of the fifth operational amplifier via resistor R4, the inverted local TX signal is connected to the non-inverting input of the fifth operational amplifier via resistor R8, and the feedback resistor R9 is connected between the output pin and the non-inverting input of the fifth operational amplifier.

2. The circuit as described in claim 1, characterized in that, The values ​​of resistors R11, R12, and R13 are in the range of 5KΩ to 10KΩ; the values ​​of resistors R14 and R15 are in the range of 5KΩ to 10KΩ; and the value of resistor R16 is 80 to 100 times that of R15.

3. The circuit as described in claim 1, characterized in that, The values ​​of resistors R1, R2, R3, R5, R6, and R7 range from 5KΩ to 10KΩ; the values ​​of resistors R4 and R8 range from 5KΩ to 10KΩ; and the value of resistor R9 is 80 to 100 times that of R8.

4. The circuit as described in any one of claims 1-3, characterized in that... The first to fifth operational amplifiers in the 4-line dedicated line detection circuit and the 2-line dedicated line detection circuit are implemented using 3 dual operational amplifiers or 5 single operational amplifiers.

5. A link detection method in a leased line communication process, characterized in that... It includes the following steps: Construct a 4-wire dedicated line detection circuit and a 2-wire dedicated line detection circuit as described in any one of claims 1-4; receive signals at the RX terminal; Detect whether the DETECT1 and DETECT2 signals change; if the DETECT1 and DETECT2 signals change continuously, it indicates that the corresponding link is normal; if the DETECT1 and DETECT2 signals remain unchanged, it indicates that the corresponding link is disconnected.

6. An electronic device, characterized in that, The electronic device includes a processor and a memory for storing executable instructions of the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the link detection method in the leased line communication process as described in claim 5.

7. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which is used to execute the link detection method in the leased line communication process as described in claim 5.

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