Network line fault monitoring device

Abstract

The present application relates to a monitoring device for network line fault. The circuit of the device comprises a sampling circuit and a fault processing circuit. The sampling circuit inputs the corresponding state signal of the monitored line into the fault processing circuit. The fault processing circuit comprises a subtraction circuit composed of analog operational amplifier chips and a voltage comparison circuit. The voltage comparison circuit compares the signal outputted by the subtraction circuit with its corresponding value and outputs the corresponding signal of the monitored network line.

Description

Technical Field

[0001] This invention relates to devices for short-term disconnection of the accompanying cable of monitoring equipment and short-term poor contact of the connector plug. Background Technology

[0002] The cable connecting the control cabinet to the moving object is called the traveling cable. During operation, some equipment may experience momentary interruptions in its traveling cable, or occasional poor contact at the connector, causing the equipment to stop briefly before immediately resuming normal operation. Alternatively, certain functions may malfunction briefly before quickly returning to normal. These types of faults are difficult to locate, often requiring highly skilled personnel to spend considerable time monitoring the equipment to pinpoint the problem. Sometimes, when a fault occurs, technicians are too slow to react, and the equipment returns to normal, leaving them with insufficient time to monitor the situation. For example, when an elevator is running at full speed, the safety circuit of its traveling cable may momentarily break, causing the elevator to stop abruptly for about two seconds, causing panic among passengers. The elevator then automatically returns to normal. This type of fault sometimes occurs only once a day or every few days. The elevator traveling cable mentioned here refers to the cable connecting the control cabinet and the car. Summary of the Invention

[0003] The purpose of this invention is to monitor the status of network lines in the accompanying cables of equipment, addressing the problem of occasional momentary disconnections and recovery in these lines, making fault diagnosis difficult. The network lines monitored by this device refer to network lines with terminating resistors, including line connection points, etc. The technical solution for monitoring network lines in this invention is as follows: The circuitry of this device includes a sampling circuit and a fault handling circuit. The sampling circuit inputs the corresponding status signal of the monitored line to the fault handling circuit, which includes a subtraction circuit composed of an analog operational amplifier chip and a voltage comparison circuit. The voltage comparison circuit compares the signal output by the subtraction circuit with its corresponding value and outputs the corresponding signal of the monitored network line.

[0004] The sampling circuit has two connection methods: One type is the series monitoring method. The characteristic of the series monitoring method is that the device disconnects the monitored line into two parts, and then connects the two parts of the monitored line with two corresponding leads. A voltage drop element is connected in parallel with these two leads, that is, the voltage drop element is connected in series into the monitored line, and the voltage signal on the voltage drop element is used as the detection signal. In this series monitoring method, the electrical connection position between the device and the monitored equipment can be located at any position on the monitored line; the position can be at the front end or the rear end, or any suitable location for placing the device. Another type is the parallel monitoring method. The characteristic of the parallel monitoring method is that the corresponding lead of this device is connected in parallel with the monitored line; its electrical connection position with the monitored equipment is located at any position on the monitored line, or at any position on other lines connected to the monitored line.

[0005] A series monitoring method is adopted: The connection method is as follows: Let the line to be monitored by the monitored equipment be denoted as line (A). Divide line (A) into two disconnected ends, denoted as (485CPU) and (485CAR) respectively. Electrically connect (485CPU) and (485CAR), and the negative power supply terminal of the signal from line (A), i.e., the negative power supply terminal of the network cable, to the corresponding ports of this device. Here, the disconnected end closest to the main signal source is denoted as (485CPU). See appendix. Figure 1 ; The term "component" in the following discussion of resistors, capacitors, diodes, and other similar components refers to an equivalent component. For example, a resistor can be a combination of several resistors connected in series or in parallel to produce an equivalent resistance that meets the required resistance value. Other equivalent components are similar in this respect.

[0006] The sampling circuit for this series monitoring method: Its voltage drop element is connected in series in the monitored line, that is, the voltage drop element is electrically connected to the two broken wire ends (485CPU) and (485CAR) of the monitored line respectively. The voltage drop element may also be connected in parallel with a small capacity capacitor. The sampling circuit may also include a current limiting circuit, the circuit structure of which is as follows: a power supply is connected to the disconnected wire (485CPU) through a resistor, and another resistor is connected to the disconnected wire (485CAR) and the negative terminal of the power supply of the network line respectively; the function of this circuit is that when there is no current between the two wires of the network line at a certain time, the current limiting circuit generates a small current through the terminating resistor of the network line, so that the voltage drop element generates a voltage; the current limiting circuit may include an adjustable resistor, adjusting the resistor can minimize the impact of the voltage generated by the current limiting circuit on the network line and the voltage when the network line is idle; The voltage drop element can be a diode, transistor, Zener diode, resistor, optocoupler transmitter, or other similar components. They can be used individually or in combination. When current flows through the monitored line, there will be a corresponding voltage value on the voltage drop element; when the monitored line is disconnected, there will be no voltage on the voltage drop element.

[0007] The subtraction circuit of the fault handling circuit in this series monitoring method: The two voltages across the voltage drop element in the sampling circuit of this device, namely the voltage signals on (485CPU) and (485CAR), are respectively input into the same subtraction circuit containing an analog operational amplifier. This subtraction circuit amplifies the voltage difference across the voltage drop element and outputs a corresponding line status signal. This operational amplifier can be a chip similar to the LM358. When the monitored line is disconnected, the amplitude of the signal voltage output by the subtraction circuit will be lower than the value when the line is normal. The voltage comparison circuit of the fault handling circuit in this series monitoring method compares the signal output by the subtraction circuit with its corresponding voltage reference value, and outputs a signal that reflects the disconnection status of the monitored line. This voltage reference value may also be adjustable. The voltage comparison circuit configuration of the fault handling circuit in this series monitoring method is as follows: It mainly uses a circuit composed of voltage comparator chips, such as the LM393 comparator chip, or uses an operational amplifier chip as a voltage comparator, such as the LM358. This voltage comparator circuit compares the voltage signal sent by the subtraction circuit directly or after transformation with the corresponding comparison reference voltage. After transformation by this circuit, the corresponding signal is output. Alternatively, a circuit composed of an adjustable voltage reference chip similar to TL431 can be used. The voltage signal from the subtraction circuit is input to the adjustment terminal of the voltage reference chip after being divided by resistors, and it is also input to the cathode of the voltage reference chip through resistors. When the voltage signal from the subtraction circuit is lower than the corresponding value, the chip is cut off, and the corresponding signal is output after being transformed by the circuit. Alternatively, a circuit composed of a Zener diode with a certain voltage can be used. The voltage signal from the subtraction circuit is input to the cathode of the Zener diode through a resistor. When the voltage signal from the subtraction circuit is lower than the Zener diode's conduction value, the Zener diode is turned off. After being transformed by this circuit, the corresponding signal is output.

[0008] Parallel monitoring method: The connection method of this parallel monitoring method is as follows: its port leads are respectively connected to the corresponding network lines with terminating resistors of the monitored pair, or also connected to the negative power supply of the network line. The sampling circuit for this parallel monitoring method: The electrical signal of the monitored network line is input to the corresponding filter circuit or rectifier filter circuit. Their filtering method is to use RC filtering with resistor and capacitor. The RC filtering is the signal after the ripple signal passes through the resistor, and then passes through the capacitor to remove noise and obtain the required signal as the sampling signal. This signal is then input to its corresponding subtraction circuit. The rectification methods of this rectifier and filter circuit are as follows: the circuit method in which both signals of the monitored network line are input to the same rectifier and filter circuit is bridge rectification; or the signals of the network line are rectified by their respective half-wave rectification and the cathodes of their two diodes are connected; the circuit method in which the signals of the monitored network line are input to their respective rectifier and filter circuits is half-wave rectification. A filter circuit is used.

[0009] The subtraction circuit of the fault handling circuit in this parallel monitoring method: The signal output from its sampling circuit is input to the corresponding subtraction circuit. The subtraction circuit is mainly composed of analog operational amplifier chips, such as the LM358. The corresponding line status signal output by the subtraction circuit is the amplified value of the sampled signal after subtracting its corresponding comparison reference voltage. The comparison reference voltage can be adjusted, for example, by adjusting the adjustable resistor. The voltage comparison circuit of the fault handling circuit in this parallel monitoring method: Its circuit structure is similar to that of the voltage comparison circuit in the series monitoring method mentioned above. It mainly uses a circuit composed of voltage comparator chips, or a circuit composed of an adjustable voltage reference chip similar to TL431, or a circuit composed of a Zener diode of a certain voltage; the corresponding reference voltage of the voltage comparison circuit can be adjusted.

[0010] The fault signal output by this network cable fault monitoring device can alert relevant personnel in multiple ways. Attached image description: Figure 1 This is the series wiring diagram for the monitored lines. Figure 2 This is a sampling circuit diagram for a series monitoring network line. Figure 3 Example diagrams of subtraction circuits and voltage comparison circuits connected in series for monitoring network lines. Figure 4 This is a series voltage comparator circuit. Figure 5 This is the sampling circuit diagram for the parallel monitoring network lines. Figure 6 This is a subtraction circuit diagram for parallel monitoring network lines. Figure 7 This is a circuit diagram for a voltage comparison circuit connected in parallel to monitor network lines. Figure 8 This is the overall diagram of the device. Implementation

[0012] Series connection: Its sampling circuit: Pins (4), (3), and (1) of the terminal voltage drop element are connected to (485CPU), (485CAR), and reference ground potential, respectively. Diodes (D2) and (D3) are connected in reverse parallel, then in parallel with capacitor (C1), and then connected to (485CPU) and (485CAR) respectively; see Appendix Figure 2 ; Its current limiting circuit consists of resistor (R1) connected to the positive terminal of the power supply (VCC) and (485CPU), and resistor (R2) connected to the power supply ground and (485CAR); see attached. Figure 2 .

[0013] Its fault handling circuit includes a subtraction circuit: The (485CPU) signal, after passing through the filter circuit, is input to the + terminal of (U1A). The (485CAR) signal, after passing through the filter circuit, is input to the + terminal of (U1B). A resistor (R4) is connected in parallel between the - terminal of (U1A) and its output terminal. A resistor (R5) is connected between the - terminal of (U1B) and ground. A resistor (R3) is connected in parallel between the - terminal and the output terminal of (U1B). A resistor (R6) is connected between the output terminal of (U1A) and the - terminal of (U1B). Pin (8) of (U1A) and (U1B) is connected to (+VCC), and pin (4) is connected to (-VCC). See Appendix. Figure 3 ; The resistance values ​​of (R4) and (R5) in the subtraction circuit are equal, and the resistance values ​​of (R3) and (R6) are equal. The subtraction circuit amplifies the voltage signal difference between (485CPU) and (485CAR) proportionally. The output voltage of (U1A) is processed by the corresponding rectifier and filter circuit to obtain a positive voltage signal (VO+) and a negative voltage signal (VO-) respectively. The voltage comparison circuit of its fault handling circuit is as follows: A voltage comparator circuit composed of comparator chips is used: (VO+) is connected to pin 3 of comparator (U2A), and (VO-) is connected to pin 6 of comparator (U2B); pin 2 of (U2A) is connected to the reference voltage (VREF1), and pin 5 of (U2B) is connected to the reference voltage (VREF2); resistor (R7) is connected to the output of (U2A) and the base of transistor (Q2); resistor (R2) is connected in series with the output of (U2B) to the base of transistor (Q1); the emitters of (Q1) and (Q2) are grounded; the collectors of (Q1) and (Q2) are connected in parallel to the signal (OFFNET); resistor (R1) is connected to the power supply (VCC) and (OFFNET) respectively; (OFFNET) is the fault signal of the monitored line; see appendix. Figure 3 ; (OFFNET) is high when the line is disconnected, otherwise it is low.

[0014] The voltage comparator circuit using the TL431 chip: The signal output from the subtraction circuit is rectified to output two power supplies, (V+) and (V-). (V+) is connected to one pin of resistors (R2) and (R3), respectively. The other pin of (R2) is connected to pin (1) of optocoupler (U1). Pin (2) of (U1) is connected to pin (2) of TL431 (U3). (V-) is connected to pin (3) of (U3) and one pin of (R4). Pin (1) of (U3) is connected to the other pin of (R3) and (R4), respectively. Pin (3) of (U3) is connected to the power supply ground. Pin (4) of (U3) is connected to the signal (OFFNET). Resistor (R1) is connected to the power supply (VCC) and (OFFNET), respectively. (See attached diagram) Figure 4 .

[0015] A voltage comparator circuit using Zener diodes: The signal output from the subtraction circuit is rectified to output a power supply (V+) and (V-). (V+) is connected to one pin of resistor (R6), and the other pin of (R6) is connected to pin (1) of optocoupler (U1). (V-) is connected to the anode of Zener diode (D1), and the cathode of (D1) is connected to pin (2) of optocoupler (U2). Pin (3) of (U3) is connected to ground, and pin (4) of (U3) is connected to signal (OFFNET). Resistor (R5) is connected to power supply (VCC) and (OFFNET) respectively. See Appendix. Figure 4 .

[0016] Working principle: When the monitored network line is disconnected, the sampling elements (D2) and (D3) of its sampling circuit have no current and the voltage across them is zero volts; the output voltage of the subtraction circuit is also zero volts. The output signal of the subtraction circuit is rectified and filtered to the voltage comparison circuit, which compares it with the reference voltage. The voltage comparison circuit outputs a high-level signal, which is then transformed to output a fault signal (OFFNET).

[0017] Parallel connection method: Its sampling circuit: The cathodes of diodes (D1) and (D2) are connected to one pin of resistor (R1), and the pins of (D1) and (D2) are connected to the signal terminals (485A) and (485B) of the monitored line, respectively; the other pin of (R1) is connected to one pin of capacitor (C1), and the other pin of (C1) is grounded; (485A), (485B), and ground are connected to the corresponding monitored line through the connector of this device, see Appendix. Figure 5 .

[0018] Its fault handling circuit includes a subtraction circuit: (U1A) and (U1B) are two sub-components of the operational amplifier chip TP2264. Pin (6) of (U1B) is connected to one pin of resistors (R1) and (R2), respectively. The other pin of (R1) is grounded. Pin (7) of (U1B) is connected to the other pin of (R2) and one pin of resistor (R3), respectively. Pin (2) of (U1A) is connected to the other pin of (R3) and one pin of resistor (R4), respectively. Pin (1) of (U1A) is connected to the other pin of (R4) and the signal (… (VOUT) is connected, pin (5) of (U1B) is connected to signal (V1), pin (3) of (U1A) is connected to signal (V+), pin (4) of (U1A) is connected to the positive power supply (VCC), and pin (11) of (U1A) is connected to the negative power supply, i.e., grounded. (V1) is also connected to resistor (R5), pin (1) of (R6), and one pin of capacitor (C1). The other pin of (R5) is connected to (VCC), pins (2) and (3) of (R6) are connected and then grounded, and the other pin of (C1) is grounded. See Appendix. Figure 6 .

[0019] The voltage comparison circuit of its fault handling circuit is as follows: Pin (9) of the operational amplifier chip (U1C) is connected to the signal (VOUT), which is the filtered signal of the subtraction circuit output signal (V+); pins (1) and (2) of the adjustable resistor (R4) are shorted, and are respectively connected to one pin of the resistor (R3), one pin of the capacitor (C2), and pin (10) of (U1C); the other pin of (R3) is connected to the power supply (VCC); pin (1) of (R4) is grounded; the other pin of (C2) is grounded; the resistor (R5) is connected to pin (8) of (U1C) and the base of the transistor (Q1); the fault signal (485H) is connected to one pin of the resistor (R6) and the collector of (Q1); the emitter of (Q1) and pin (11) of (U1C) are grounded; the other pin of (R6) and pin (4) of (U1C) are connected to (VCC). When the monitored line is disconnected, signal (VOUT) is high, pin (8) of (U1C) is low, and signal (485H) is high, indicating a fault. See Appendix. Figure 7 ; Working principle: When the monitored network line is disconnected, the amplitude of its output signal will increase; the voltage output by the sampling circuit will increase, and the signal (VOUT) output by the subtraction circuit will also increase. It is input to the voltage comparator circuit and compared with the reference voltage. The voltage comparator circuit outputs a high level to drive the transistor (Q1) and obtain the fault signal (485H).

[0020] The implementation conditions used in this embodiment can be further adjusted according to the specific manufacturer's conditions. The implementation conditions not specified are usually the conditions in routine experiments. This embodiment is only for illustrating the concept and features of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It cannot be used to limit the scope of protection of the present invention. The wire end markings, component markings, wire numbers, etc., described above are only for the convenience of understanding this device and should not be construed as limiting the scope of this invention. The component markings and text labels in the accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this device; all equivalent transformations or modifications made according to the spirit and essence of this invention should be included within the scope of this invention.

Claims

1. A device for monitoring network cable faults, characterized in that: It includes a sampling circuit and a fault handling circuit. The fault handling circuit includes a subtraction circuit composed of an analog operational amplifier chip and a voltage comparison circuit.

2. The network cable fault monitoring device according to claim 1, characterized in that: The sampling circuit can be connected in series or in parallel. In series monitoring, its electrical connection with the monitored equipment can be located anywhere on the monitored line. In parallel monitoring, its electrical connection with the monitored equipment can be located anywhere on the monitored line or any other line connected to the monitored line.

3. The serial monitoring method according to claim 1, characterized in that: The voltage drop element of its sampling circuit is connected in series in the monitored line, and the voltage drop element may also be connected in parallel with a small capacity capacitor.

4. The serial monitoring method according to claim 1, characterized in that: Its sampling circuit may also include a current limiting circuit. The current limiting circuit is structured as follows: a power supply is connected to the broken wire head (485CPU) through a resistor, and another resistor is connected to the broken wire head (485CAR) and the negative terminal of the power supply of the network cable respectively; its electrical connection with the monitored equipment is located at any position on the monitored line.

5. The serial monitoring method according to claim 1, characterized in that: The two voltages across the voltage drop element in its sampling circuit are respectively input to the same subtraction circuit consisting of an analog operational amplifier. The subtraction circuit amplifies the voltage difference across the voltage drop element and outputs a corresponding line status signal.

6. The parallel monitoring method according to claim 1, characterized in that: The electrical signals of the network lines being monitored are input to the corresponding filter circuits or rectifier filter circuits, and their filtering method is RC filtering using resistors and capacitors; The rectification methods of this rectifier and filter circuit are as follows: the circuit method in which both signals of the monitored network line are input to the same rectifier and filter circuit is bridge rectification; or the signals of the network line are rectified by their respective half-wave rectification and the cathodes of their two diodes are connected; the circuit method in which the signals of the monitored network line are input to their respective rectifier and filter circuits is half-wave rectification.

7. The parallel monitoring method according to claim 1, characterized in that: The subtraction circuit of its fault handling circuit is that the output signal of its sampling circuit is input to the corresponding subtraction circuit. The output of the corresponding line status signal of the subtraction circuit is the amplified value of the sampled signal after subtracting its corresponding comparison reference voltage. The comparison reference voltage may be adjustable.

8. The network cable fault monitoring device according to claim 1, characterized in that: Its voltage comparison circuit can also adjust the voltage reference value.

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