JPH0370836B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a line continuity monitoring device in fire alarm equipment.

In fire alarm equipment, a device that monitors the continuity of the line of each district line that connects the receiver and a plurality of detectors installed in each warning area has conventionally been used, for example, by connecting a resistor to the end of the line. However, there are methods that perform this by constantly monitoring the current flowing through the termination resistor, and methods that perform this by connecting an oscillator to the termination and constantly monitoring its output. Since line continuity monitoring is performed for each district line,
When the above-mentioned line breaks, even if it is possible to determine which district line the line belongs to, it is not possible to determine the location of the disconnection in that district line.

In view of the above points, the present invention has been developed so that each sensor connected in parallel for each district line sequentially monitors the connection state of the district line to the line in the subsequent sensor, and prevents disconnection in the subsequent sensor. By activating the own disconnection display means when detecting disconnection to the above-mentioned line based on the basis of This allows for easy identification.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, Re is a receiver, and a district relay N is connected in series with the power source E, and a voltage is connected in parallel to the series circuit of the power source E and the district relay N. A detection circuit VD ₂ and a pulse detection circuit PD are connected respectively, and this voltage detection circuit is connected between the output side of the voltage detection circuit VD ₂ and the pulse detection circuit PD and the positive terminal of the power supply E.
VD ₂ and a disconnection indicator light Lb is connected through an OR circuit OR controlled by a pulse detection circuit PD. Moreover, De ₁ , De ₂ ~ _{De o} are connected to a single line with the line ₁ connected to the positive terminal of the power source E of the receiver Re and the line ₁ connected to the negative terminal of the power source E through the district relay N. Line ₂ forming the district line
There are multiple sensors connected in parallel between the two sensors, all of which have the same structure. i.e. each sensor
As shown in FIG. ₂ , De 1 , De ₂ to _{De o} are a fire detection circuit FD, a voltage detection circuit VD ₁ , a pulse generation circuit PG controlled by the voltage detection circuit VD ₁ ,
A series circuit consisting of the confirmation light La, a transistor Q ₁ connected in parallel with each other controlled by the above-mentioned fire detection circuit FD and pulse generation circuit PG, Q ₂ connected in series with a resistor R ₁ , and between the base and emitter. A series circuit consisting of a transistor Q ₃ connected to a resistor R ₂ and a resistor R ₃ connected to its base is connected in parallel to each other between the lines ₁ and ₂ . The input side of the voltage detection circuit VD ₂ of the receiver Re is connected to the line ₂ through the resistor R ₇ , and also to the collector of the transistor Q ₃ of the foremost sensor De ₁ through the resistor R ₆ and the line ₃ . In addition, the input side of the voltage detection circuit VD ₁ of the sensors De ₁ to De _o-1 is connected to the line ₂ through the resistor R ₅ , and also senses the line ₄ in the case of the resistor R ₄ and the sensor De ₁ . In the case of the sensors De ₂ to De _o-1 , the terminals are connected to the collectors of the transistors Q 3 of the subsequent sensors De ₂ to De _o in sequence through the line ₅ , and then to the collectors of the transistors Q ₃ of the rearmost sensors De _o
The input side of the voltage detection circuit VD ₁ is connected to the line ₂ through a resistor R ₅ and also to the line ₁ through a resistor R ₄ .

In Figure 1, only a single district line is shown and other district lines are omitted; however, in reality, each district line is connected to the above power supply E, respectively. .

Next, to explain its operation, the constant power supply E
The voltage excluding the voltage drop of the district relay is
₁ and ₂ , and the conduction of the transistor _Q3 of each sensor _De1 , _De2 ~ _Deo is applied to the voltage detection circuit VD2 of the receiver Re, and that of the sensor _De1 is applied to the voltage detection circuit VD2 of the receiver Re, and the conduction of the transistor _Q3 of each sensor De1, _De2 ~Deo is
De _o is monitored by the voltage detection circuit VD ₁ of the preceding sensor De ₁ ~ _{De o-1} , but each line
If ₁ , ₂ , and ₃ to ₅ are all normal, the voltage across resistor _R5 or _R7 will maintain a predetermined value because the transistor _Q3 is conductive due to the voltage drop across resistor _R2 . Since the voltage detection circuit VD ₁ or VD ₂ does not operate and produces no output, the pulse generation circuit PG of each sensor De ₁ to De _o-1 also does not operate, and therefore the transistor Q ₂ Since there is no conduction, in the receiver Re, the pulse detection circuit PD does not operate in the same way as the voltage detection circuit VD ₂ described above, so the OR circuit OR does not operate, and the disconnection indicator light of the receiver Re and the sensors De ₁ to _{De o- 1} confirmation light La
does not light up or flash. If a fire occurs in this state and the fire detection circuit FD of a certain sensor is activated, its output will cause transistor Q ₁ to conduct and the impedance between lines ₁ and ₂ will become low through the confirmation light La, causing a fire to be transmitted to the receiver Re. A signal is sent to activate district relay N, which activates a device (not shown) to issue a fire alarm.
The display will be displayed, and the confirmation light La of the sensor will light up.

When the lines ₁ , ₂ or ₃ to ₅ are disconnected, the disconnection point is between the sensors De ₁ and De ₂ to De _o , for example, section a between the sensors De ₁ and De ₂ ,
If it is in section b or section c, the sensor
Transistor Q ₃ of De ₂ ceases to conduct, and the voltage across the resistor R ₅ of the sensor De ₁ in front of it decreases, causing the voltage detection circuit VD ₁ of the same sensor De ₁ to operate and produce an output. The pulse generating circuit PG operates, transistor _Q2 becomes conductive intermittently, and the confirmation light La and the line are connected.
₁ and ₂ , a pulse signal as a disconnection signal is sent to the receiver Re. Then, the pulse signal is received by the receiver Re, the pulse detection circuit PD operates, and the output causes the disconnection indicator light Lb to be turned on by the OR circuit OR.
This circuit lights up through tracks ₁ , ₂ or
It is displayed that wires ₃ to ₅ are disconnected. Note that lighting of this indicator light Lb alone does not indicate that line ₁ ,
Even though I knew that wires ₂ or ₃ to ₅ were disconnected,
The above line from the receiver Re to the last sensor De _o
1 , ₂ or ₃ to ₅ , but in the above sensor De ₁ , the transistor Q ₂ is intermittently turned on by the output of the pulse generator PG, and the confirmation light La is turned on. Flashing.
In other words, if there is a disconnection in section a, section b, or section c, at least the sensor immediately after the disconnection point
In De ₂ , the transistor Q ₃ becomes non-conductive, but the voltage detection circuit VD ₁ can detect the resulting voltage drop across the resistor R ₅ at the sensor De ₁ immediately before the disconnection point. Therefore, by blinking the confirmation light La of this sensor De ₁ ,
Line ₁ , ₂ or ₃ to ₅ disconnection points are detected by the detector.
It can be seen that this is section a, section b, or section c between De ₁ and De ₂ .

Note that the above-mentioned sensors De ₁ , De ₂ to _{De o} all have the same structure, so the last sensor De _o is connected to a resistor R so that its voltage detection circuit VD ₁ does not operate all the time. It is directly connected to line ₁ through ₄ , and if there is a disconnection in section d, the voltage detection circuit VD ₁ of the same sensor De _o will operate and perform the same operation as above, and its confirmation light La will blink. However, in the sensor De _o , there is no subsequent sensor, so there is no need for a means to monitor the conduction of the transistor _Q3 , and even if the circuit is disconnected in the section d, the function of this sensor De _o will not be affected. Therefore, the voltage detection circuit VD ₁ , pulse generation circuit PG, transistor Q ₂ and the like may be removed, and in that case, the line in section d is of course unnecessary.

Also, e between the receiver Re and the foremost sensor De ₁
If there is a disconnection in the section, f section, or g section, the voltage detection circuit VD ₂ of the receiver Re operates due to the non-conduction of the transistor Q ₃ of the sensor De ₁ , and directly lights the disconnection indicator light Lb through the OR circuit OR. .

In other words, if lines ₁ , ₂ or ₃ to ₅ are disconnected, the disconnection indicator light Lb of the receiver Re lights up, making it possible to determine that the disconnection is the local line, and furthermore, only this indicator light Lb lights up. By lighting up, the disconnection point of the above lines ₁ , ₂ or ₃ to ₅ is connected to the receiver Re and the frontmost sensor.
De ₁ is in section e, section f, or section g, and the blinking of the confirmation light La of the sensor De ₁ to De _o-1 indicates that the above-mentioned disconnection point is in the section e, f, or g between the sensor De _{1 and De o-1} .
For example, it is possible to determine that the current is in section a, section b, or section c between De _o-1 and the subsequent sensors De ₂ to De _o .

The voltage across the above resistor _R5 or _R7 is:
It also decreases when transistor Q ₁ becomes conductive in the event of a fire, but its value is lower than that of resistors R ₄ , R ₅ or R ₆ , R ₇
Therefore, when the lines ₁ , ₂ or ₃ to ₅ are disconnected, the voltage does not decrease to the value when the transistor _Q3 becomes non-conductive, so the voltage detection circuit VD does not operate. In addition, when the line is disconnected, transistor _Q2 is intermittently conductive and lines ₁ and ₂ are disconnected.
Even when a pulse signal is sent between
Between ₁ and ₂ , the impedance is intermittently low, but
The resistor R ₁ prevents the voltage from dropping to a value that causes the district relay N of the receiver Re to operate, and also ensures that the pulse width of the pulse signal becomes shorter than the operating time of the district relay N. Therefore, the district relay N will not operate due to line breakage.

As described above, according to the present invention, a district line consisting of a pair of power and signal lines connected to a receiver is provided for each warning area, and when a fire occurs in each district line, the fire is transmitted to the receiver through the district line. In a fire alarm system in which a plurality of sensors that transmit signals are connected in parallel, the last one among the plurality of sensors connected to the same district line is connected at least to the district line. power supply detection means for detecting the power supply from the district line; and power supply signal output means for outputting a power supply signal to the immediately preceding sensor when the power supply detection means detects the power supply from the district line. Each sensor except the last one has a power supply detection means for detecting the power supply from the district line, and the power supply detection means detects the power supply from the district line. A power supply signal output means for outputting a power supply signal to the immediately preceding sensor; a power supply signal detecting means for detecting a power supply signal output from the immediately preceding sensor; and the power supply signal detecting means. a disconnection signal sending means for sending out a disconnection signal different from a fire signal sent in the event of a fire to the district line when the power supply signal is no longer detected; and a disconnection signal being sent by the disconnection signal transmitting means. The receiver is provided with a power supply signal detection means for detecting a power supply signal output from the foremost sensor, and a power supply signal detection means for detecting a power supply signal outputted from the foremost sensor; A disconnection signal detection means for detecting a disconnection signal output from the sensor operates when the power supply signal detection means no longer detects a power supply signal or when the disconnection signal detection means detects a disconnection signal. The power supply signal detection means of each sensor except the last one is connected to the power supply signal output means of the immediately following sensor through the signal line, and the power supply signal detection means of the receiver is provided. means is connected to the power supply signal output means of the foremost sensor through a signal line, and when the line of the district line is disconnected, the disconnection to the line in the sensor immediately after the disconnection point is determined by the disconnection. The power supply signal detecting means of the sensor or receiver immediately before the point detects the disconnection, and the disconnection is indicated on the receiver by the disconnection display means. If a sensor detects a disconnection, the sensor will also display a disconnection using its disconnection display means, so conventional continuity monitoring devices can only detect disconnections. In addition to identifying the district line that has been disconnected, it is also possible to determine the location of the line break in that district line. It also eliminates the need for sending wiring between each sensor on the line, which was an essential condition in conventional continuity monitoring equipment, so it is possible to Therefore, it is possible to arbitrarily branch and route the lines, and therefore the sensor wiring work can be carried out freely, and the installation of additional sensors can also be done easily. When performing branch wiring, if it is necessary to separately monitor each sensor immediately after the branch,
The sensors at the branch points may be provided with the corresponding monitoring means.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing one embodiment of the present invention, Figure 2 is a circuit diagram showing an embodiment of the present invention.
The figure is a detailed circuit diagram of the sensors De ₁ , De ₂ to De _o in FIG. 1. Re...receiver, De ₁ , De ₂ ~ _{De o} ...sensor,
₁ , ₂ , ₃ , ₄ , ₅ ...Line, La...Confirmation light, Lb...Disconnection indicator light, FD...Fire detection circuit,
VD ₁ , VD ₂ ... Voltage detection circuit, PG ... Pulse generation circuit, PD ... Pulse detection circuit, Q ₁ , Q ₂ , Q ₃ ...
...transistor.

Claims (1)

[Scope of Claims] 1. A district line consisting of a pair of power and signal lines connected to a receiver is provided for each warning area, and each district line is capable of transmitting a fire signal to the receiver through the district line when a fire occurs. In a fire alarm system consisting of a plurality of sensors connected in parallel, each of which sends out a A power supply detection means for detecting power supply; and a power supply signal output means for outputting a power supply signal to the immediately preceding sensor when the power supply detection means detects power supply from the district line. Each sensor other than the last one is provided with a power supply detection means for detecting power supply from the district line, and the power supply detection means detects power supply from the district line. A power supply signal output means for outputting a power supply signal to the immediately preceding sensor; a power supply signal detecting means for detecting a power supply signal output from the immediately preceding sensor; and the power supply signal detecting means. a disconnection signal sending means for sending out a disconnection signal different from a fire signal sent in the event of a fire to the district line when the power supply signal is no longer detected; and a disconnection signal being sent by the disconnection signal transmitting means. The receiver is provided with a power supply signal detection means for detecting a power supply signal output from the foremost sensor, and a power supply signal detection means for detecting a power supply signal outputted from the foremost sensor; A disconnection signal detection means for detecting a disconnection signal output from each sensor and the power supply signal detection means operate when the power supply signal detection means no longer detects a power supply signal or when the disconnection signal detection means detects a disconnection signal. The power supply signal detection means of each sensor except the last one is connected to the power supply signal output means of the immediately following sensor through the signal line, and 1. A line continuity monitoring device for fire alarm equipment, characterized in that the signal detection means is connected to the power supply signal output means of the foremost sensor through a signal line. 2. The disconnection signal sending means is connected in parallel with a pulse generation circuit that operates when the power supply signal detection means no longer detects a power supply signal, and a switching circuit that is rendered conductive by the output of the fire detection circuit, and the above-mentioned pulse generation It consists of a switching circuit that intermittently conducts between the district lines at a predetermined impedance by the output of the circuit, and the disconnection indicating means consists of a confirmation light connected between the district lines through a parallel circuit of both of the switching circuits. Claim 1
Line continuity monitoring device for the fire alarm equipment described in Section 3.