JPH0792876B2 - Fire detection terminal - Google Patents

Description

The present invention relates to a fire detection terminal used in an automatic fire alarm system.

[Prior Art] FIG. 2 is a schematic configuration diagram of an automatic fire alarm system using a time division multiplex transmission system. In this system, N fire detection terminals T ₁ , T ₂ , ..., T _N are monitored by one receiver (or relay) R. Each of the fire detection terminals T _{1 to} T _N has a built-in fire detector that generates an analog fire detection signal, converts the analog fire detection signal into a digital signal, and transmits it via the transmission line l. It is transmitted to the receiver R. Fire detectors that generate analog fire detection signals include smoke concentration detectors that generate analog signals according to smoke concentration, room temperature detectors that generate analog signals according to room temperature, or flames. There is an infrared sensor that generates an analog signal according to the detection amount of infrared rays with a wavelength of 4.3 μm.

In this type of automatic fire alarm system, each fire detection terminal
It is necessary to regularly check whether T _{1 to} T _N can be reported normally. Therefore, each of the fire detection terminals T _{1 to} T _N has a built-in pseudo alarm element for changing the fire detector to the alarm state, and the receiver R
It is equipped with a remote check control function that activates the pseudo-reporting element by remote control from to perform a reporting test.

For example, according to Japanese Patent Laid-Open No. 53-77199, in a remotely operable fire detector, a heating element or a smoke emitting element is driven by a check signal following an address signal to forcibly apply heat or smoke to the sensor. , Remote check control for creating a pseudo fire condition and checking the quality of the sensor is disclosed.

[Problems to be Solved by the Invention] In the conventional remote check control, when the alarm test control signal is received from the receiver R, the pseudo alarm element immediately starts to operate and forces the analog signal of the fire detector. The level is changed to the level at the time of a fire. As a result, the analog signal that has reached the alarm level is digitized and sent back to the receiver R. Therefore, during remote check control, the analog signal of the fire detector does not become a signal that correctly measures the data necessary for fire monitoring such as smoke density, room temperature, infrared ray amount, etc. in the monitored area. Therefore, even if an actual fire condition occurs during the remote check control, there is a problem that the receiver R cannot know it. In addition, even if there is an abnormality such as insufficient sensitivity in the fire detector during remote check control, the analog signal of the fire detector reaches the alarm level due to the operation of the pseudo alarm element. There was a problem that he could not know.

The present invention has been made in view of such a point, and an object thereof is to notify even if a fire state or an abnormal state has occurred during remote check control for performing a warning test by remote operation. It is to provide a fire detection terminal that can do.

[Means for Solving the Problem] In order to solve the above-mentioned problems, the fire detection terminal device according to the present invention, as shown in FIG. 1, outputs an analog signal necessary for fire detection. A detector 1, a pseudo alarm element 2 forcibly setting the fire detector 1 to the alarm state, an A / D converter 3 for digitizing an analog signal from the fire detector 1, and an A / D conversion A level determination unit 4 for determining whether the digital signal output from the unit 3 is a normal level, an abnormal level, or a warning level, and a control signal is received via an external transmission line 1 and a reply signal is transmitted. Signal transmission unit 5 for replying
When the signal transmission unit 5 receives the alarm test control signal, if the determination result of the level determination unit 4 is a normal level, the pseudo alarm element 2 is operated, and if it is an abnormal level, the pseudo alarm element 2 is activated. Alarm test control unit 6 and signal transmission unit 5
When the alarm test control signal is received by the level determination unit 4
If the determination result of is a normal level, the output data of the A / D conversion unit 3 after the operation of the pseudo reporting element 2 and the data indicating that the test is issued are used as the reply signal of the signal transmission unit 5, and the determination result is obtained. If is an abnormal level, the output data of the A / D conversion unit 3 is used as a reply signal of the signal transmission unit 5, and if the determination result is a warning level, it is not the output data of the A / D conversion unit 3 and the test report. And a reply signal setting unit 7 that uses the data indicating the above as a reply signal of the signal transmission unit 5.

[Operation] According to the present invention, as described above, if the determination result of the level determination unit 4 is a normal level when the alarm test control signal is received, the pseudo alarm element 2 is operated to detect an abnormal level. If there is, the pseudo alarm element 2 is not operated. Therefore, if the analog signal output from the fire detector 1 is at an abnormal level, it is not changed to the alarm level.
It is possible to notify the abnormality of the fire detector 1 by replying as it is. If the determination result of the level determination unit 4 is a normal level when the alarm test control signal is received, data indicating that the alarm is a test alarm is returned, and if the determination result is the alarm level, the test is issued. Since the data indicating that it is not an alarm is sent back, even if a fire condition has occurred during the alarm test, this can be notified.

[Embodiment] FIG. 1 is a block diagram of a fire detection terminal T according to an embodiment of the present invention. The fire detection terminal T has a built-in analog fire detector 1. Examples of the analog fire detector 1 include a smoke concentration sensor that generates an analog signal according to smoke concentration, a room temperature sensor that generates an analog signal according to room temperature, or a wavelength 4.3 included in a flame.
There is an infrared sensor or the like that generates an analog signal according to the detected amount of infrared rays of μm. The pseudo alarm element 2 forcibly sets the fire detector 1 to the alarm state during the alarm test. The warning state of the fire detector 1 is, for example, a state in which a smoke concentration detection signal having a certain concentration or more, a room temperature detection signal having a certain temperature or more, and an infrared ray detection signal having a certain amount or more are output as analog signals.

The analog signal output from the fire detector 1 is converted into a digital signal in the A / D conversion unit 3, and the level determination unit 4
The level is judged at. FIG. 3 shows the level L of the analog signal output from the fire detector 1. In the figure, L ₃ is the maximum value of the analog signal, L ₂ is the analog value at the time of alarm, and L ₁ is the analog value at the time of abnormality. The level determination unit 4 determines that the level L of the analog signal of the fire detector 1 is L ₁ or less, it is determined to be an abnormal level, and if it is greater than L _{1 and} less than L ₂ , it is determined to be a normal level. L ₂
If it is above, it is determined that the notification level.

Next, the signal transmission unit 5 will be described. The signal transmission unit 5 is connected to the receiver R via a transmission line 1. Transmission line l
Is a two-wire type cable such as a coaxial cable, and as shown in FIG. 2, a plurality of terminals T _{1 to} T _N and one receiver R are connected in parallel between the lines. From the receiver R, a start signal indicating the start of signal transmission, an address signal for designating a terminal device to communicate with, a control signal for controlling the operation of the terminal device, and a reply signal from the terminal device are received. A time-division multiplex transmission signal including at least a reply time zone for sending the signal and an end signal indicating the end of signal transmission is sent to the transmission line l. The address signal and the control signal are, for example, a plurality of bits (for example, 8 bits) serial signals meaning that the long voltage pulse is “1” and the short voltage pulse is “0”. In the reply time zone, for example, by applying a voltage between the transmission lines 1 on the receiver R side and shorting or opening the lines between the transmission lines 1 on the terminal side via a resistor, For example, a multi-bit (for example, 8 bits) serial signal, which means that the long current pulse is “1” and the short current pulse is “0”, is received by the receiver R.
Reply to. The address signal and the control signal are transmitted from the receiver R as a low impedance voltage signal, and in the signal transmission unit 5, the rectifier and the smoothing capacitor are connected between the lines of the transmission line l to operate the operating power of the terminal device T. It has gained.

The address signal included in the time division multiplex transmission signal transmitted from the receiver R has changed so as to cyclically poll each of the terminal units T _{1 to} T _N, and only one terminal unit whose address signal matches Performs a control operation and a reply operation according to the control signal. In order to assign this address signal, the signal transmission unit 5 is provided with an address setting means such as a DIP switch and an E ² PROM, and each terminal device T ₁ ...
Unique address signals are set so that they do not overlap for T _N.

When the start signal is received from the transmission line 1, the signal transmission unit 5 receives the address signal that follows it and compares it with its own address signal. If the address signals do not match, then the next start signal is received. If the address signals match, the control signal that follows them is received, and the fire monitoring operation and the alarm test operation are selectively executed according to the control signal. Hereinafter, each operation will be described.

The alarm test control unit 6 does not operate during the fire monitoring operation. In this case, the analog signal obtained from the fire detector 1 is A / D
It is converted into a digital signal by the conversion unit 3, set in the reply signal setting unit 7, and returned to the receiver R. As a result, the receiver R can digitize and receive the analog signal required for fire detection from each of the terminals T _{1 to} T _N. The receiver R stores a table showing the correspondence between the addresses of the terminals T _{1 to} T _N and the types of fire detectors. By referring to this table, the received signal indicates that the smoke concentration Signal indicating room temperature or a signal indicating room temperature,
It is determined whether the signal indicates the detected amount of infrared rays.

Next, during the alarm test operation, the alarm test control unit 6 operates, and under the control of the alarm test control unit 6, the level determination unit 4 determines the output level of the A / D conversion unit 3. FIG. 4 is a flow chart showing the operation of the terminal when the alarm test control signal is received. As shown in the figure, when the alarm test control signal is received, the level of the current analog value is judged, and it is determined whether the judgment result is the normal level, the abnormal level, or the alarm level. And perform another action. The operation in each case will be described below.

(A) At the normal level, if the determination result of the level determination unit 4 is the normal level, the pseudo-reporting element 2 is operated under the control of the reporting test control unit 6. As a result, the level of the analog signal output from the fire detector 1 rises to the warning level. This analog signal is digitized by the A / D conversion unit 3 and set in the reply signal setting unit 7. Further, the level determination unit 4 sets a code indicating that the test is issued in the reply signal setting unit 7. Here, the reply signal setting unit 7 is composed of, for example, a shift register, the data output from the A / D conversion unit 3 and the level determination unit 4 is written as parallel data, and read as serial data in the reply time zone, It is supplied to the signal transmission unit 5. Therefore, in the receiver R,
The fire detection signal raised to the alarm level and the data indicating that the alarm is a test alarm will be received, whereby the test alarm is issued.

(B) At the abnormal level, if the determination result of the level determination unit 4 is the abnormal level, the reporting test control unit 6 does not operate the pseudo reporting element 2. As a result, the level of the analog signal output from the fire detector 1 remains at the abnormal level. This analog signal is
It is digitized by the D conversion unit 3 and set in the reply signal setting unit 7. Therefore, the receiver R receives the fire detection signal of the abnormal level, and the abnormality is notified. The abnormality notification here is to notify that there is a failure such as a decrease in the sensitivity of the fire detector 1, a disconnection of the wiring, or a disconnection, and urges the user to inspect the fire detection terminal T.

(C) At the alarm level, if the determination result of the level determination unit 4 is the alarm level, it is output from the fire detector 1 without needing to activate the pseudo alarm element 2 by the alarm test control unit 6. Since the level of the analog signal that has reached
Digitized by the A / D converter 3 and returned by the reply signal setting unit 7
Set to. Further, the level determination unit 4 sets a code indicating that the test is not issued in the reply signal setting unit 7. Therefore, the receiver R receives the fire detection signal reaching the alarm level and the data indicating that the alarm is not the test alarm, whereby the fire alarm is performed.

[Effects of the Invention] According to the present invention, as described above, in the fire detection terminal equipped with the fire detector that outputs the analog signal necessary for fire detection, the analog signal of the analog signal is received when the alarm test control signal is received. It is determined whether the level is a normal level, an abnormal level, or a reporting level, and if it is a normal level, the pseudo reporting element is operated and the analog signal is digitized and returned together with the data indicating that the test is reporting, If it is an abnormal level, the analog signal is digitized and returned without operating the pseudo alarm element, and if it is an alarm level, the analog signal is digitized and returned together with data indicating that it is not a test alarm. If the fire detector outputs a warning level or an abnormal level analog signal at the time of receiving the warning test control signal, it is possible to notify this. .

[Brief description of drawings]

FIG. 1 is a block diagram of a fire detection terminal according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of an automatic fire notification system using the fire detection terminal of the above, and FIG. FIG. 4 is an explanatory view for explaining the level of the analog signal for fire detection in the terminal, and FIG. 4 is a flow chart for explaining the alarm test operation of the fire detection terminal. 1 is a fire detector, 2 is a pseudo alarm element, 3 is an A / D converter,
Reference numeral 4 is a level determination unit, 5 is a signal transmission unit, 6 is an alarm test control unit, 7 is a reply signal setting unit, T is a fire detection terminal, 1 is a transmission line, and R is a receiver.

Claims (1)

[Claims] 1. A fire detector that outputs an analog signal necessary for fire detection, a pseudo alarm element that forcibly sets the fire detector to a warning state, and an analog signal from the fire detector is digitized. Via an external transmission line, an A / D conversion unit, a level determination unit that determines whether the digital signal output from the A / D conversion unit is a normal level, an abnormal level, or a notification level, and an external transmission line. A signal transmission unit that receives a control signal and sends back a reply signal, and if the determination result of the level determination unit is a normal level when the notification test control signal is received by the signal transmission unit, operate the pseudo alarm element. If it is an abnormal level, the pseudo-reporting element that does not operate the pseudo-reporting element and the pseudo-reporting element if the judgment result of the level judgment section is normal when the signal transmission section receives the report-testing control signal Output data of the A / D converter after the If the judgment result is an abnormal level, the output data of the A / D converter is used as the reply signal of the signal transmission unit, and the judgment result is the notification level. If so, a fire detection terminal device comprising an output data of the A / D conversion unit and a reply signal setting unit that uses data indicating that the test is not issued as a reply signal of the signal transmission unit.