JPH0887689A - Fire sensor - Google Patents

Abstract

PURPOSE: To provide the fire sensor with which a fire alarming system can be constructed at low cost and test work is enabled without necessity to go to the place where the fire sensor is installed. CONSTITUTION: When a transmitted signal from a sensor line Ls is received, a signal discriminating part 3 inputs the transmitted signal to a signal processing part 6. At the signal processing part 6 where the transmitted signal is received, test processing is performed by dispatching a test signal corresponding to the contents of the transmitted signal to a fire/test processing part 6. When the output terminals of the fire/test processing part 4 are short-circuited corresponding to the detection of fire due to a sensor 5, on the other hand, the sensor line Ls is short-circuited through the signal discriminating part 4, and the amount of a current to flow to the sensor line Ls is changed. Therefore, only the function for detecting the current change is enough for the receiver in the case of detecting the generation of fire, and it is enough only to connect a testing device for transmitting the transmissive signals to the sensor line Ls in the case of testing the fire sensor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire detector connected to a receiver via a two-wire type detector wire.

[0002]

2. Description of the Related Art Conventionally, fire detection is connected to a sensor line through which a signal for inspection is transmitted, and when a signal for inspection is received, a test process is performed and the result is sent to the sensor line. Vessels are provided. This kind of fire detector
An address is given to each fire detector, and a time-division or frequency-division transmission signal containing the address is sent to the detector line from the receiver or repeater, and the transmission signal is sent to the fire detector with the same address. After the test processing is performed based on the contained information, the result of the test processing is returned to the receiver or the repeater. Moreover, when a fire is detected by a detection unit such as a smoke sensor, a warning signal is sent together with the address to notify the receiver or the repeater of the fire.

That is, as shown in FIG. 4, the fire detector 1 is connected to the receiver 2 through a detector line Ls, and therefore the receiver 2 is time-divided or frequency-divided. Transmission unit 11 for transmitting / receiving multiplexed transmission signals
Is provided, and when a warning signal from the fire detector 1 is received, a fire processing unit 12 that performs various kinds of processing corresponding to the fire occurrence, and displays the fire occurrence and instructs the test processing of the fire detector 1 A display operation unit 13 for performing the operation is provided.

Now, as a transmission signal, a digital value of 1,
A bipolar digital signal whose pulse width is modulated so that the pulse width changes corresponding to 0 is used. The transmission signal is a start pulse indicating the start of the signal, and each fire detector 1 is individually designated. It is set as a period for the receiver 2 to receive address data, mode data for instructing the test process or the fire detection process by the detector, control data for instructing the contents of the test process, and a return signal from the fire detector 1 It is assumed that the signal is a time division multiplexed signal including the signal return period. The transmission signal also includes error check bits for checking and correcting transmission errors.

When such a transmission signal is sent from the receiver 2 to the detector line Ls, the fire detector 1 having an address matching the address data included in the transmission signal receives the transmission signal and the mode data is tested. If it is a process, a test process such as whether or not it operates normally is performed, and the result is returned to the receiver 2 in synchronization with the signal return period. Further, when a fire is detected by the fire detector 1, an alarm signal is sent to the receiver 2 in synchronization with the transmission signal, and the processing associated with the fire occurrence is performed. Here, the receiver 2 cyclically accesses each fire detector 1 and returns a warning signal when each fire detector 1 is accessed, and the receiver 2 does not have a specific address. A dummy transmission signal is always sent, and when the fire detector 1 sends a warning signal, an interrupt signal is generated in synchronization with the dummy transmission signal,
There is a type in which the receiver 2 can access the fire detector 1 by returning the address to the subsequent search by the receiver 2.

[0006]

As described above, when the receiver 2 and the repeater are provided with the function of transmitting and receiving the transmission signal, the transmission section 11 for transmitting and receiving the transmission signal to and from the receiver 2 and the repeater.
Must be built in, which causes a problem that the entire fire alarm system becomes expensive. On the other hand, conventionally, it is connected to a 2-wire type sensor line in which a specified voltage is applied between the lines, and when a fire occurs, the amount of current flowing through the sensor line is changed by changing the impedance inserted between the sensor lines ( For example, a fire detector has been conventionally provided in which a contact is inserted between lines and the contact is turned on to short-circuit the line when a fire occurs). Although this type of fire detector simplifies the configuration of the receiver, it is not possible to instruct the fire detector test process from the receiver side. It is necessary to go to the installation site and actually operate the fire detector, which causes a problem that the test work takes time.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, a fire alarm system can be realized at a low cost with a simple receiver structure, and the test work can be performed up to the installation location of the fire detector. It is an object of the present invention to provide a fire detector that can be intensively performed at one place even if it is not.

[0008]

In order to achieve the above object, the present invention provides a fire detector connected to a receiver through a two-wire type sensor line in which a specified voltage is applied between the lines. There is a detection unit that detects a fire and a fire / test processing unit that changes the impedance between the output ends when a fire occurrence is detected based on the output of the detection unit and performs a test process when a test signal is input from the outside. When a transmission signal of a predetermined format is received, the transmission processing unit that passes the information included in the transmission signal as a test signal to the fire / test processing unit and the output end of the fire / test processing unit between the sensor lines In addition, it is inserted between the sensor line and the transmission processing unit, and when a fire occurs, a fire
When the transmission signal is transmitted to the sensor line by changing the amount of current flowing through the sensor line by changing the impedance between the output ends of the test processing unit, the sensor line is connected to the transmission processing unit and the transmission signal is delivered. And a section.

[0009]

According to the above construction, the fire detector is provided with the signal discriminating section for discriminating whether or not the transmission signal of the predetermined format is transmitted to the sensor line, and when the transmission signal is transmitted,
Since the fire / test processing unit performs the test processing, at the time of the test, by connecting the test device capable of transmitting the transmission signal to the sensor line and receiving the return signal from the fire sensor to the sensor line, 1 without going to the installation location
Fire detector testing can be directed at the location. Also, in the signal discrimination section, the output terminals of the fire / test processing section are inserted between the sensor lines, so when a fire occurs
The amount of current flowing in the sensor line changes due to the impedance change between the output terminals of the test processing unit.Therefore, the receiver side should adopt a configuration that can detect this current change. It is not necessary to have the function of sending and receiving.

After all, since the signal from the fire detector at the time of a fire can be detected by the change in the current flowing through the detector line, the configuration of the receiver and the repeater can be simplified and the fire alarm system can be manufactured at low cost. It can be realized, and when the fire detector is tested, the test of the fire detector can be performed from a distance by connecting a test device provided separately from the receiver to the detector wire.

[0011]

EXAMPLE As shown in FIG. 1, a fire detector 1 according to the present embodiment includes a signal discriminating section 3 connected to a sensor line Ls, and the signal discriminating section 3 uses a conventional technique through the sensor line Ls. It is determined whether or not the pulse-width-modulated and time-division-multiplexed transmission signal is transmitted, and when the transmission signal is received, the transmission signal is delivered to the transmission processing unit 6 described later. The sensor line Ls is a two-wire type, and a specified voltage is applied between the lines by a receiver or a repeater. The signal discriminating unit 3 is inserted between the output end of the fire / test processing unit 4 and the sensor line Ls. In the fire / test processing unit 4, the presence or absence of a fire is judged based on the output of the detection unit 5 including a smoke detector and a heat detector, and when the fire occurs, the impedance between the output terminals is changed.
Since the output terminals of the fire / test processing unit 4 are connected between the sensor lines Ls via the signal discriminating unit 3, when a fire occurs, the impedance change between the output terminals of the fire / test processing unit 4 is performed. As a result, the amount of current flowing through the sensor line Ls changes. Here, it is common to insert a contact between the output ends of the fire / test processing unit 4 and turn on the contact when a fire occurs, thereby short-circuiting the lines of the sensor line Ls. A series circuit with an impedance may be inserted between the sensor lines Ls. In either case, when a fire occurs, the sensor line Ls
It is sufficient that the amount of current flowing through the receiver increases and the receiver and the repeater are configured to be able to detect this increase in current. That is, the fire alarm system can be constructed at low cost because the receiver and the repeater do not need a configuration for transmitting and receiving a transmission signal.

On the other hand, in the signal discrimination section 3, the sensor line Ls
When it is detected that the pulse width modulated and time division multiplexed transmission signal is transmitted, the transmission signal from the sensor line Ls is delivered to the transmission processing unit 6. In the transmission processing unit 6, an address is set individually for each fire detector 1, and when the address data included in the transmission signal matches this address, other information included in the transmission signal is read to create a test signal. , Delivers a test signal to the fire / test processing unit 4. In the fire / test processing unit 4 to which the test signal is input, a pseudo alarm is issued according to the test content (the fire / test processing unit 4 is connected to the sensor line Ls and the same sensor as when a fire occurs). Test processing such as changing the amount of current flowing through the line Ls), returning information about the state of the fire detector 1 and performing an operation test of the detection unit 5 is performed. These series of tests are well known and are also performed on conventional fire detectors. Also, the test result is sent to the sensor line Ls through the transmission processing unit 6. Transmission processing unit 6
The method of receiving the transmission signal and returning the test result through the same method is the same as the conventional configuration.

As described above, if there is an instruction of the test processing by the transmission signal, the test is performed and the test result is sent to the sensor line Ls. In other cases, the sensor line Ls is sent according to the operation of the detector 5. The fire detector 1 can be used even when a receiver or a repeater that does not have a transmission signal processing function is used because the amount of current of the detector is changed, and the test device is connected to the detector line Ls as necessary. Then, the test process can be performed without going to the installation location of the fire detector 1. Of course, if it is not necessary to construct a low-cost system, a receiver or a repeater having a transmission signal processing function may be used.

FIG. 2 shows a structural example of a fire alarm system using the fire detector 1 having the above structure. Here, the switch 7 is inserted in the sensor line Ls connecting the receiver 2 and the fire sensor 1. The switch 7 selects whether to connect the fire detector 1 to the receiver 2 or to an external device. Here, the switch 7 is provided outside the receiver 2, but inside the receiver 2. It may be provided. At the time of use as a fire alarm system, as shown in FIG. 2, the fire detector 1 is connected to the receiver 2 by the switcher 7, and changes in the amount of current flowing through the detector line Ls due to the occurrence of a fire are selected. To detect. on the other hand,
When performing the test work, as shown in FIG. 3, the receiver 2 is disconnected from the fire detector 1 by the switch 7 so that the test device 8 can be connected to the detector line Ls. If the test device 8 is connected to the detector line Ls in this state, the test process of the fire detector 1 can be performed.

In the above embodiment, the signal discriminating unit 3 has a structure in which the fire / test processing unit 4 is always connected to the sensor line Ls and the transmission signal is delivered to the transmission processing unit 6 only when the transmission signal is received. Although adopted, the signal discriminating unit 3 may be configured to selectively connect only one of the fire / test processing unit 4 and the transmission processing unit 6 to the sensor line Ls depending on the presence or absence of a transmission signal. . In this case, the false alarm during the test process is
It may be returned in synchronization with the transmission signal.

[0016]

As described above, according to the present invention, the fire detector is provided with the signal discriminating portion for discriminating whether or not the transmission signal of the predetermined format is transmitted to the sensor line, and when the transmission signal is transmitted. Since the fire / test processing unit performs test processing,
During testing, by connecting a test device that can send the transmission signal to the detector line and receive the return signal from the fire detector to the detector line, you can detect the fire at one place without going to the installation location of the fire detector. There is an advantage that the test of the vessel can be instructed. In addition, since the output terminal of the fire / test processing unit is inserted between the sensor lines in the signal discrimination unit, when a fire occurs, the impedance changes between the output terminals of the fire / test processing unit cause it to flow into the sensor line. Since the amount of current changes and the receiver can adopt a configuration capable of detecting this current change, there is an advantage that the receiver does not need to have a function of transmitting and receiving a transmission signal.

After all, since the signal from the fire detector when a fire occurs can be detected by the change in the current flowing through the detector line, the configuration of the receiver and the repeater can be simplified and the fire alarm system can be manufactured at low cost. Further, when the fire detector is tested, a test device provided separately from the receiver is connected to the detector wire, so that the fire detector can be tested from a distance.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment.

FIG. 2 is a configuration diagram showing a usage pattern of the embodiment.

FIG. 3 is a configuration diagram showing a usage pattern of the embodiment.

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1 Fire Detector 2 Receiver 3 Signal Discrimination Section 4 Fire / Test Processing Section 5 Detector 6 Transmission Processing Section 7 Switcher 8 Test Equipment Ls Sensor Line

Claims (1)

[Claims] 1. A fire detector connected to a receiver through a two-wire type sensor line in which a specified voltage is applied between the lines, the detection unit detecting a fire and the output of the detection unit. When a fire outbreak is detected based on the above, the impedance between the output terminals is changed, and a fire / test processing unit that performs a test process when a test signal is input from the outside, and the information included in the transmission signal when a transmission signal of a predetermined format is received Is passed as a test signal to the fire / test processing section, and the output line of the fire / test processing section is connected between the sensor wire and the fire processing by inserting it between the sensor wire and the transmission processing section. Fire at the time of occurrence
When the transmission signal is transmitted to the sensor line by changing the amount of current flowing through the sensor line by changing the impedance between the output ends of the test processing unit, the sensor line is connected to the transmission processing unit and the transmission signal is delivered. A fire detector, characterized by comprising: