KR101350694B1 - Input repeater having function for detecting line disconnection - Google Patents

Abstract

The present invention relates to an input repeater having a line break detection function for transmitting a fire detection signal and a line break detection signal from a detector to a receiver so as to alarm the fire detection signal for receiving a fire occurrence detection signal from the detector. Receiving unit; A line break detection unit detecting a line break signal of a detector connected to the fire detection signal receiver; An abnormal signal transmitter configured to receive the fire detection signal and the line disconnection detection signal and transmit the received signal to a receiver; And a central processing unit for controlling the input / output signals of the fire detection signal receiver, the line break detection unit, and the abnormal signal transmission unit. Can be.

Description

INPUT REPEATER HAVING FUNCTION FOR DETECTING LINE DISCONNECTION}

The present invention relates to an input repeater having a line break detection function, and more particularly, an input having a line break detection function that detects and copes with a line break of a plurality of detectors installed in a fire-prone area in a building in advance. It is about a repeater.

In recent years, with economic growth, buildings have become higher, larger, and more complex, and thus, various fire alarm systems have been adopted to protect buildings and lives from fire.

That is, a fire detector for detecting heat or smoke is installed in a fire-prone area in the building, and the fire detector is connected to the central control room to receive a detection signal according to the fire so as to cope with the fire immediately.

As an example, the prior art according to the integrated disaster prevention broadcasting system that provides a evacuation path by detecting a fire position through a detector is disclosed in Korean Patent Application No. 2010-0029772.

Disaster prevention broadcasting integrated system according to the prior art, as shown in Figure 1, is installed in each of the preset zones for detecting a fire occurring inside the building (20-1 ~ 20-n); A repeater connected to the fire detector and transmitting a fire detection signal according to the fire detector detecting a fire; Recognizes a fire point according to the fire detection signal received through the fire detector and the repeater, searches for the evacuation path of each section corresponding to the fire point and the internal structure of the building, and each guide corresponding to the evacuation path A central processing unit 50 for outputting a message; And a speaker 10-1 to 10-n installed in each section and warning the fire signal by voice outputting a guide message received from the central processing unit.

However, the repeater of the integrated disaster prevention broadcasting system providing an evacuation route by using the fire location according to the prior art as described above, is provided with a separate function to detect and respond to the disconnection in the line of the plurality of connected fire detector line, There is a problem that does not exist.

In other words, the fire detector is composed of various kinds of semiconductor elements and various sensors, and operates by receiving external operating power continuously. When the fire detector is continuously supplied with power, deterioration occurs in the internal semiconductor elements. In case of no operation or impact by external construction, the line of the detector line is disconnected and it is not possible to notify of the occurrence of fire.It is necessary to check the operation state of the detector line or whether the line is disconnected in real time before the fire. Function is required.

Republic of Korea Patent Application No. 2010-0029772 (Name: Disaster prevention broadcasting integrated system and method for providing an evacuation route using the fire location, Applicant: Himax Co., Ltd. 1, Filed: 2010, 04, 11)

The present invention is to solve the above problems, the object is to check in real time whether the line disconnection of the plurality of detector lines installed in the fire-prone area in the building through the line disconnection detection unit in the repeater, due to the disconnection of the detector It is to provide an input repeater with a line disconnection detection function that can thoroughly prepare for fire occurrence in advance by alarming through a receiver when not in operation.

The input repeater with a line break detection function according to the present invention for achieving the above object, as an input repeater 200 to transmit a fire detection signal from the detector 100 to the receiver 300 to alarm Fire detection signal receiving unit for receiving a fire detection signal from the detector 100; A line break detection unit 212 for detecting a line break signal of the detector 100 connected to the fire detection signal receiving unit 210; An abnormal signal transmitter 214 for receiving the fire detection signal and the line disconnection detection signal and transmitting the received signal to the receiver 300; And a central processing unit 230 for controlling input and output signals of the fire detection signal receiving unit 210, the line disconnection detecting unit 212, and the abnormal signal transmitting unit 214. The input unit is connected to the central processing unit 230. The voltage monitoring reset circuit unit 220 further includes a voltage monitoring reset circuit 220 for resetting the central processing unit 230 when an unstable voltage flows into the repeater 200. The voltage monitoring reset circuit unit 220 includes a regulator IC for maintaining a constant voltage (5V). U3), a resistor R37 connected to one end of the IC U3 and the other end connected to a power supply terminal Vcc, and a capacitor C12 connected to one end of the resistor R37 and grounded.

Preferably, a terminal resistor is connected to an end of the line of the detector 100, and the line disconnection detector 212 detects whether a line is disconnected by sensing a current flowing through the terminal resistor.

More preferably, when the line of the detector 100 is disconnected, the line break detection unit 212 may include a first switching element Q2 that is switched to a 'high' level by preventing a voltage from flowing to a termination resistor and the first switch. The second switching element Q1 switched to the 'low' level according to the switching of the switching element Q2, and the photocoupler PC2 driven according to the switching of the second switching element Q1 to transfer the line disconnection detection signal. It consists of

In addition, the input repeater 200 further includes a communication lamp display unit 226 composed of a resistor R29 and a light emitting diode L2 to indicate that the line break detection unit 212 detects whether the detector 100 is disconnected. Include.

In addition, the receiver 300 includes an operation display unit 304 and an alarm unit 306 for alerting that the line break detection unit 212 detects a line break of the detector 100.

In addition, the abnormal signal transmitter 214 receives the line disconnection detection signal through the capacitor C3 to the base of the Darlington transistor Q5, and applies a resistor R19 to the emitter of the Darlington transistor Q5. By connecting to form a constant current circuit and transmits to the receiver 300 through the communication lines (PA, PB).

According to the input repeater having a line break detection function according to the present invention, by checking the operating state and the line break of the detector line installed in a plurality of specific places in the building in real time, through the receiver line disconnection and non-operation through the receiver By displaying and alarming, it is possible to thoroughly prepare for fires in advance.

Other objects and advantages of the present invention will become apparent from the detailed description of the embodiments with reference to the attached drawings.

1 is a view for explaining the integrated disaster prevention broadcasting system according to the prior art.
2 is an overall configuration diagram showing an example of a fire alarm system to which an input repeater with a line break detection function according to the present invention is applied.
Figure 3 is a block diagram showing the configuration of an input repeater with a line break detection function according to the present invention.
4 is a circuit diagram showing an input repeater having a line break detection function according to the present invention.
Figure 5 is a photograph showing the appearance of the input repeater with a line break detection function according to the present invention.
Figure 6 is a photograph showing the internal configuration of the input repeater with a line break detection function according to the present invention.
Figure 7 is a circuit diagram showing the configuration of the fire detection signal receiving unit, line disconnection detection unit, fire test and recovery unit of the input repeater according to the present invention.
8 is a circuit diagram showing the configuration of an error signal transmitting unit and a control command receiving unit of the input repeater according to the present invention.
9 is a circuit diagram showing a configuration of a constant voltage circuit portion of an input repeater according to the present invention.
10 is a circuit diagram showing the configuration of the voltage monitoring reset circuit and the clock oscillator of the input repeater according to the present invention.
11 is a circuit diagram showing a configuration of an address setting unit of an input repeater according to the present invention;
12 is a diagram showing an example of address setting of an input repeater according to the present invention;
13 is a circuit diagram showing the configuration of a communication lamp display unit of the input repeater according to the present invention.
14 is a view showing an example of an operation display unit and an alarm unit of a receiver applied to the present invention.

Hereinafter, an input repeater having a line break detection function according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

First, a fire alarm system to which the present invention is applied will be described with reference to FIG. 2.

2 is an overall configuration diagram illustrating an example of a fire alarm system to which an input repeater having a line disconnection detection function according to the present invention is applied.

As shown in FIG. 2, the fire alarm system to which the present invention is applied includes a detector 100, an input repeater 200, a receiver 300, an output repeater 350, and a fire processor 370.

Specifically, the detector 100 is installed in a plurality of fire-prone areas of the building to detect when a fire occurs and delivers it to the input repeater 200, a heat sensor, smoke sensor, infrared sensor and gas Any one of the sensing sensors can be used.

The input repeater 200 is a means for transmitting whether the fire and the line break through the detector 100 to the receiver 300, a detailed description thereof will be described later.

The receiver 300 receives a fire detection signal and a line disconnection detection signal from the input repeater 200 and transmits control commands to a plurality of detectors and input / output repeaters installed in a possible fire zone in a building. The monitoring unit 302 for monitoring or coping with fire through the detector 100 and the input / output repeaters 200 and 350, and an operation display unit operated according to a fire detection signal generation and line break generation signal of the detector 100 ( 304 and an alarm unit 306, and a fire test and recovery signal transmission unit 308 for transmitting a fire test and recovery signal to the detector (100).

The output repeater 350 receives a fire related control command from the receiver 300 and transmits it to the fire processor 370 installed in the corresponding area.

The fire processor 370 is a means to be controlled according to a control command from the output repeater 350, a fire alarm such as a bell, an evacuation light, a fire shutter and a smoke damper may be used.

2 to 14, an input repeater having a line disconnection detection function according to the present invention will be described in detail.

Figure 3 is a block diagram showing the configuration of an input repeater with a line break detection function according to the present invention, Figure 4 is a circuit diagram showing an input repeater with a line break detection function according to the present invention, Figure 5 is a present invention Figure 6 is a photograph showing the appearance of the input repeater with a line break detection function according to the present invention, Figure 6 is a photograph showing the internal configuration of the input repeater with a line break detection function according to the present invention.

In addition, Figure 7 is a circuit diagram showing the configuration of the fire detection signal receiving unit, line break detection unit, fire test and recovery unit of the input repeater according to the present invention, Figure 8 is an error signal transmission unit and control command receiving unit of the input repeater according to the present invention 9 is a circuit diagram showing the configuration of the constant voltage circuit section of the input repeater according to the present invention, and FIG. 10 is a circuit diagram showing the configuration of the voltage monitoring reset circuit section and the clock oscillation section of the input repeater according to the present invention.

11 is a circuit diagram showing the configuration of the address setting unit of the input repeater according to the present invention, FIG. 12 is a view showing an example of address setting of the input repeater according to the present invention, and FIG. 13 is a diagram of the input repeater according to the present invention. It is a circuit diagram which shows the structure of a communication lamp display part, and FIG. 14 is a figure which shows an example of the operation | movement display part and the alarm part of the receiver applied to this invention.

3 and 4, the input repeater 200 having a line break detection function according to the present invention is a fire detection signal receiving unit 210, a line break detection unit 212, the abnormal signal transmission unit 214 , Control command receiver 216, constant voltage circuit 218, voltage monitoring reset circuit 220, clock oscillator 222, address setting unit 224, communication lamp display unit 226, fire test and recovery unit 228 And a central processing unit (CPU) 230.

In detail, the fire detection signal receiver 210 is connected to a plurality of detectors 100 installed in a fire-prone area in a building to supply power for the operation of the detector 100 and at the same time the detector ( Receive fire detection signal from 100).

That is, as shown in Figure 7, the fire detection signal receiving unit 210 is a fire occurs when the detector 100 is operated by heat or smoke, the resistor R1 connected to the power supply terminal (+ 24V) (as an example , 68Ω), a resistor R3 (for example, 1.2kΩ) and a diode D1 sequentially connected to the resistor R1, and a switching element Q3 is connected through a resistor R10 (for example, 1kΩ) connected to one side of the resistor R1. 'Turned on', current flows through the resistor R14 (for example, 3.3kΩ), the photocoupler PC3 and the light emitting diode L1 which are sequentially connected to the collector of the switching element Q3, so as to know the operating state of the detector. RB0 port is a high level due to the pull-up resistor R2 (e.g., 100 kΩ), but is changed to a low level due to the operation of the photocoupler PC3. Receive detection signal according to fire occurrence .

At this time, a capacitor C2 is connected between the base of the switching element Q3 and the power supply terminal 24V to absorb line noise.

On the other hand, if the line disconnection detection unit 212 is disconnected the line of the detector 100 connected to the fire detection signal receiving unit 210, even if a real fire occurs, the detector 100 does not operate, such a detector 100 As a means for detecting the disconnection of the line, a terminating resistor (for example, 10 kΩ) is connected to the end of the line of the detector 100 line, and the current flowing through the terminating resistor is monitored to detect whether the line is broken.

That is, as shown in FIG. 7, when the line of the line break detector 212 is normally connected to the line of the detector 100, the base voltage of the switching element Q2 connected to the power supply terminal is a resistor R15 (for example, 470 kΩ) and It flows through the diode D1 to the local termination resistor to the "Low" level, which causes the collector voltage of the switching element Q2 to become the "high" level, which is connected to the collector of the switching element Q2. Since the voltage at the base of the switching element Q1 is at the "High" level, the collector voltage of the switching element Q1 is at the "Low" level, and the resistor R11 connected to the collector of the switching element Q1 (for example, Since no current flows through the photocoupler PC2 through 12 kΩ), the RB1 port of the central processing unit 230 receives the voltage through the pull-up resistor R3 as it is, so that a signal is transmitted as a "high" level.

However, when the line of the detector 100 is in an open state, the base voltage of the switching element Q2 connected to the power supply terminal does not flow to the terminating resistor, which leads to a "high" level, which causes the switching element Q2. The collector voltage of becomes the "Low" level, so that the voltage of the base of the switching element Q1 connected to the collector of the switching element Q2 becomes the "Low" level, so that the collector voltage of the switching element Q1 Since the photocoupler PC2 is driven through the resistor R11 connected to the collector of the switching element Q1, the RB1 port of the central processing unit (CPU) is changed to the "low" level. The line break of the detector 100 line can be detected in real time.

On the other hand, the abnormal signal transmission unit 214 is a central processing unit (CPU, of the input repeater 200) the fire detection signal from the fire detection signal receiving unit 210 and the line disconnection detection signal from the line disconnection detection unit 212 Received through the RA1 port of 230 and transmitted to the receiver 300 through the communication lines (PA and PB).

Specifically, as shown in FIG. 8, the fire occurrence detection signal and the line disconnection detection signal are applied to the base of the current amplifier Q5, which is a Darlington transistor, through a capacitor C3, and then connected to the emitter of the current amplifier Q5. A constant current circuit is formed by the resistor R19 (for example, 7.5 kΩ) to transmit a signal to the receiver 300.

In this case, in FIG. 8, the resistor R21 connected between the central processing unit 230 and the capacitor C3 and grounded is for pull-down, and the resistor R20 and diode connected between the capacitor C3 and the base of the current amplifier Q5 are grounded, respectively. D2 is used for bypassing the voltage accumulated in the capacitor C3.

In addition, it is preferable that the signal is transmitted between the abnormal signal transmitter 214 and the receiver 300 of the input repeater 200 using a frequency of approximately 5 kHz through a pulse code modulation scheme.

Meanwhile, the control command receiving unit 216 receives various control commands such as fire test and recovery signals from the receiver 300 through two communication lines PA and PB, and the received control command is input relay 200. Is transmitted through the RA0 port to the central processing unit 230.

At this time, it is preferable that the control command is transmitted between the receiver 300 and the control command receiving unit 216 through RS 485 communication or RS 232 communication which is an asynchronous method using two communication lines PA and PB.

That is, as shown in FIG. 8, the control command, which is a multiplexed signal input from the receiver 300 through the PB port, is transmitted to the switching element Q51 through the resistor R51 (for example, 200 kΩ) to provide the switching element Q51. As the turn-on is input to the RA0 port of the central processing unit 230 through the collector.

On the other hand, the constant voltage circuit unit 218 has a pulse power obtained from the communication lines PA and PB of approximately DC 24V, and the DC 24V power supply is 5V, which is a voltage for the central processing unit 230 of the input repeater 200 to operate. It is a means to make a constant voltage power supply.

That is, as shown in Figure 9, the input repeater 200 according to the present invention does not have a separate power supply for driving the central processing unit 230, the communication lines (PA and PB) for communication with the receiver 300 It is designed to be supplied through the pulse power input from the receiver 300 through the PA and PB port is converted into direct current (DC) through the bridge diode (BD1) and then diode D11, choke coil (CH1) and resistor The capacitor C9 is charged via R32, and is output at 12V by the Zener diodes ZD1 and 12V, in which a cathode and an anode are sequentially connected to a transistor Q10 having a collector connected between the resistor R32 and a capacitor C9 and a base of the transistor Q10. The output voltage of 12V is made of a constant voltage power supply of DC 5V through the three-terminal regulator IC (U2) and used to drive the central processing unit 230.

At this time, the diode D11 is to prevent the reverse current, the choke coil (CH1) for noise absorption, the noise absorbing capacitor C6 is connected and grounded between the choke coil (CH1) and the resistor R32, the choke coil (CH1) A bias resistor R33 is connected between the base of the transistor Q10 and the capacitor C9 is used for power supply smoothing, and the resistor R32 is used for the protection of the transistor Q10.

The voltage monitoring reset circuit 220 is a means for preventing the central processing unit 230 of the input repeater 200 from causing abnormal operation.

That is, when the voltage supplied to the central processing unit 230 of the input repeater 200 becomes unstable due to a lightning strike or external impact, abnormal operation occurs. When the voltage monitoring reset circuit 220 detects such an unstable voltage, By resetting and initializing the central processing unit 230, a stable voltage is always supplied to the central processing unit 230.

Specifically, as shown in FIG. 10, the voltage monitoring reset circuit 220 includes a resistor R37 (one end of which is connected to a three-terminal regulator IC U3 and the IC U3 and the other end of which is connected to a power supply terminal Vcc (example) 100 kΩ) and a capacitor C12 having one end connected to the resistor R37 and the other end grounded to transmit a reset signal through the MCLR port of the central processing unit 230, wherein the IC U3 has a constant voltage power supply 5V. For example, when an unstable voltage of 4.25V is reached, the output goes "low" and generates a reset signal.

On the other hand, the clock oscillator 222 is a means for providing a constant clock (Clock) for the central processing unit 230 of the input repeater 200 to operate normally, for example, 4Mhz crystal oscillator XT1 and peripheral elements ( An oscillation circuit composed of R42, C15, C16, and R39 supplies a stable clock through the ports OSC1 and OSC2 of the central processing unit 230.

At this time, as shown in FIG. 10, the clock oscillator 222 is grounded with a capacitor C16 connected to the OSC1 port of the central processing unit 230, and a resistor R39 and a capacitor C15 sequentially connected to the OSC2 port, and grounded. A resistor R42 and a crystal oscillator XT1 are connected in parallel between the OSC1 and OSC2 ports.

Meanwhile, the address setting unit 224 sets a unique address for each input repeater 200 so that the receiver 300 recognizes each input repeater through the set unique address. A unique address corresponding to each input repeater is stored.

Specifically, as shown in FIGS. 11 and 12, the address setting unit 224 addresses 1 to 127 through a binary method by an on / off state of eight dip switches SW1. Can be set, the bit becomes " low " by turning on a switch corresponding to the address bits RB0 to RB7 from the central processing unit 230 through the receiver 300, and the address bits from the receiver 300. Only when the address of the input repeater 200 and the corresponding address is communicated with the receiver 300.

At this time, it is preferable that the pull-up resistors R2 to R9 connected to the power supply terminal Vcc are connected to the respective tips of the eight dip switches SW1.

Meanwhile, as shown in FIG. 5, the communication light display unit 226 turns on or blinks the light emitting diode L2 when each input repeater 200 is normally communicating with the detector 100 and the receiver 300. It is a means for informing the administrator of the communication state of the input repeater 200.

For example, as shown in FIG. 13, the central processing unit 230 of the input repeater 200 has a checksum error because the address of the control command-related address data transmitted from the receiver 300 and the address of each input repeater 200 coincide. If does not occur, light emitting diode L2 is turned on by outputting pulse through RA2 port. In this case, it is preferable that the light emitting diode L2 protection resistor R29 is connected between the light emitting diode L2 and the RA2 port.

On the other hand, the fire test and recovery unit 228 is activated when a signal for fire test and recovery is transmitted from the fire test and recovery signal transmission unit 308 of the receiver 300 through the central processing unit 230, the detector ( By turning on (100) the test as if a fire occurred in the area, and at the same time, the means for restoring the detector by shutting off (0V) the power supplied to the detector 100 after the fire test, the detector 100 is Since there is a built-in continuous circuit (not shown) inside, it continues to operate even if the cause of fire caused by heat or smoke is removed. After the fire test through the fire test and recovery unit, the detector is restored to its original state.

Specifically, referring to FIG. 7, the fire test and the recovery will be described in detail. In the state where the central processing unit 230 of the input repeater 200 normally maintains the RC0 port at the "High" level, When receiving a fire test signal from the fire test and recovery signal transmission unit 308 of the receiver, by switching the RC0 port to the "low" level, as the power is supplied from the power supply terminal (Vcc) and the photocoupler (PC1) and the resistance The current flows through R17 to operate the switching element Q4 and at the same time, the power supplied to the detector 100 through the resistors R1, R12, and the diode D1 of the fire detection signal receiver 210 is made into a short state so as to operate the current. By forcibly flowing, as the switching element (Q3) of the fire detection signal receiving unit 210 is 'turned on' to receive a fire test signal through the RB0 port with the operation of the photocoupler PC3 and the light emitting diode L1.

In addition, the central processing unit 230 of the input repeater 200 maintains the RC0 port at a "high" level in the normal state, and receives the detector recovery signal from the fire test and recovery signal transmission unit 308 of the receiver. Upon receiving, by switching the RC0 port to the "low" level, current flows through the photocoupler PC1 and resistor R17 as power is supplied from the power supply terminal Vcc, while operating the switching element Q4. The power is not supplied through the resistor R1 and the resistor R12 of the fire detection signal receiving unit 210 to cut off the current flowing in the detector 100 to restore the detector 100 to the state before the fire.

That is, the fire test and recovery unit 228 is operated under the control of the central processing unit 230, the central processing unit 230 applies a continuous signal during the fire test, the fire test and recovery unit 228 To make a short state, and when recovering the detector, the fire test and recovery unit 228 is shorted to return the detector to its original state for only about 1 second.

On the other hand, the central processing unit 230 is the fire detection signal receiving unit 210, the line disconnection detecting unit 212, the abnormal signal transmitting unit 214, the control command receiving unit 216, constant voltage circuit unit 218, voltage monitoring reset circuit unit ( 220, the clock oscillator 222, the address setting unit 224, the communication lamp display unit 226, the fire test and recovery unit 228 is a built-in IC (U1) containing a program for controlling the function of the detector (100) And the input / output signal from the receiver 300.

Therefore, when the line of the detector 100 is disconnected from the input repeater 200 through the above-described configuration, the base voltage of the switching element Q2 of the line disconnection detector 212 connected to the power supply terminal 24V is terminated. This causes the collector voltage of the switching element Q2 to be at the "low" level, whereby the voltage at the base of the switching element Q1 connected to the collector of the switching element Q2 is lowered to the "low" level. Therefore, the collector voltage of the switching element Q1 is at the "High" level, and the photocoupler PC2 is driven through the resistor R11 connected to the collector of the switching element Q1, so that the RB1 port of the CPU is " It is changed to the "Low" level, and receives the disconnection signal of the detector 100 line.

Then, the central processing unit (CPU) outputs the line break signal from the line break detection unit 212 to the fault signal transmitter 214 through the RA1 port, and the fault signal transmitter 214 disconnects the line. The signal is transmitted to the receiver 300 through the communication lines PA and PB.

Thereafter, as shown in FIG. 14, the receiver 300 indicates that the line of the detector is disconnected through the operation display unit 304, and at the same time, fires an alarm sound through the alarm unit 306. You can check the status of the detector before it occurs.

In the above described the present invention according to an embodiment of the present invention, it is obvious that those skilled in the art belong to the present invention changes and modifications within the scope without departing from the technical spirit of the present invention. Do.

Claims (6)

As an input repeater 200 to transmit a fire detection signal from the detector 100 to the receiver 300 to alarm;
A fire detection signal receiver 210 for receiving a fire detection signal from the detector 100;
A line break detection unit 212 for detecting a line break signal of the detector 100 connected to the fire detection signal receiving unit 210;
An abnormal signal transmitter 214 for receiving the fire detection signal and the line disconnection detection signal and transmitting the received signal to the receiver 300; And
It includes a central processing unit 230 for controlling the input and output signals of the fire detection signal receiving unit 210, the line disconnection detection unit 212 and the abnormal signal transmission unit 214,
Further comprising a voltage monitoring reset circuit 220 for resetting the central processing unit 230 when the unstable voltage flows into the input repeater 200 in connection with the central processing unit 230,
The voltage monitoring reset circuit unit 220 includes a regulator IC U3 for maintaining a constant voltage (5V), a resistor R37 connected at one end thereof to the IC U3 and the other end connected to a power supply terminal Vcc, and the resistor ( Input repeater having a line break detection function, characterized in that consisting of a capacitor (C12) connected to one end of the ground (R37). The method of claim 1,
Termination resistor is connected to the end of the detector 100 line,
The line break detection unit (212) detects the current flowing through the termination resistor to detect whether or not the line disconnection. 3. The method according to claim 1 or 2,
The line break detection unit 212,
When the line of the detector 100 is disconnected, the first switching element Q2 is switched to the 'high' level because the voltage does not flow to the termination resistor, and the 'low' level according to the switching of the first switching element Q2. And a photocoupler PC2 driven according to the switching of the second switching element Q1 and transferring the line disconnection detection signal. One input repeater. 3. The method according to claim 1 or 2,
The line disconnection detector 212 further includes a communication light display unit 226 composed of a resistor R29 and a light emitting diode L2 to indicate that the detector 100 detects disconnection of the line. Input repeater with detection function. The method of claim 1,
The receiver 300 includes a line break detection function, which includes an operation display unit 304 and an alarm unit 306 for alerting that the line break detection unit 212 detects a line break of the detector 100. One input repeater. The method of claim 1,
The abnormal signal transmitter 214 receives the line disconnection detection signal through a capacitor C3 to the base of the Darlington transistor Q5 and connects a resistor R19 to an emitter of the Darlington transistor Q5. An input repeater having a line disconnection detection function, comprising: a constant current circuit configured to transmit to a receiver 300 through a communication line (PA, PB).

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