JPH03137788A - Fire sensor - Google Patents

Abstract

PURPOSE:To confirm the reliability of data stored in the same manner as a specific code by storing the specific code in a RAM and discriminating whether storage of the specific code is accurate or not at each time of fire discrimination. CONSTITUTION:The detection value from a circumstance detecting means FS is stored in a working RAM 2 and is stored in data storage RAMs 3 and 4. The specific code stored in a storage area ROM 2 is stored in a specific code storage RAM 1. The specific code in the RAM 1 is checked before signal processing for fire discrimination; and when it is normal, the difference between the current read detection value and the stored value of the RAM 4 is obtained to perform fire discrimination. When the specific code is defective, fire discrimination is not performed and a past detection value and the present detection value are exchanged. Thus, the reliability of stored data is confirmed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fire detector that detects fire using a microcomputer, read-only memory, random access memory, and the like.

[Prior art and problems] Fire detectors using microcomputers (hereinafter referred to as MPU), read-only memories (ROM'), random access memories (RAM), etc. There is a problem in that the data stored in the RAM is destroyed due to the noise, resulting in false alarms and the like due to fire judgments based on incorrect data.

In addition, a differential fire detector that detects a fire based on a change value or a difference value in the environmental condition detects a fire within - degrees and sends a fire signal to a receiving section such as a fire receiver or repeater. However, after transmission, if the receiving unit is restored to its initial state through a recovery operation and the internal memory data is unconditionally initialized, even if the fire continues, the environmental information from that fire will not be retained. Since the change value or difference value is used as the reference value for calculating the value, there was a problem that the change value or difference value of the environmental condition due to fire could not be detected, resulting in missed alarms.

[Means for Solving the Problem] Therefore, according to the present invention, there is provided an environment detection means for detecting an environmental state related to a fire phenomenon and outputting an environment detection value, and a storage means for storing the environment detection value from the environment detection means. A fire detector comprising: a signal processing means for storing over time and processing the signal at a predetermined period to determine fire; a writing means for writing a specific code into the storage means; and the signal processing means: Each time the signal processing is attempted, the specific code written in the storage means is checked, and if the content of the specific code is determined to be abnormal, the content of the storage means is initialized. A fire detector is provided, comprising: a confirmation means; and a fire detector.

According to another aspect of the present invention, there is provided an environmental detection means for detecting an environmental state during a fire phenomenon and outputting an environmental detection value; a signal processing means for chronologically storing information in a storage means and performing signal processing to determine a fire; and as a result of the fire determination, when the signal processing means determines that a fire has occurred, the signal processing means is reset. a reset means for outputting a reset signal, and when the signal processing means enters the reset state, the fire detector can return to the fire monitoring state by canceling the reset state, wherein the signal processing means is writing means for writing a specific code into the storage means before entering the reset state when the occurrence of a fire is determined; and writing means for writing a specific code into the storage means after the reset state of the signal processing means is released. A fire detector is provided, comprising: checking means for checking a specific code and initializing the contents of the storage means if the content of the specific code is determined to be abnormal; Ru.

[Operation] According to the first aspect of the present invention, by storing a specific code in a random access memory and determining whether or not this code is accurately stored, a code similar to the specific code is stored. The reliability of the stored data can be confirmed.

According to the second aspect of the present invention, the presence or absence of the specific code is checked after the reset is canceled, and if the specific code is present or the specific code is normal, the fire judgment is continued based on the environmental information before the reset. We are making this possible.

As a result, for example, in a fire detector that detects a fire based on a change value or a difference value of environmental information, reliable fire monitoring can be performed even after the reset is released.

In this case, if a counter is provided that can count the number of times the reset is canceled, and if the reset is canceled more than a predetermined number of times, the past data will be erased.
The problem of inconvenient non-fire alarms caused by extreme fluctuations in environmental conditions can be eliminated.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block circuit diagram showing an example of a fire alarm device to which the present invention can be applied, in which a fire detector SE performs fire discrimination based on environmental information regarding a fire phenomenon, and transmits the result to a power supply line 11. This shows a so-called on-off type fire alarm system in which the signal is set to low impedance and sent to the fire receiving iRE. In addition, fire reception iRE
multiple fire detectors SE via power line l4.12.
are connected in parallel, but only one of them is shown.

The power supply E in the fire reception fiRE is connected to each fire detector SE via the fire signal detection relay RL and recovery switch SW.
However, if no fire is detected, the amount of current consumed by each fire detector is small, and relay RL is not energized.

In each fire detector SE, the line voltage applied via the power supply lines 11 and 12 is regulated by a constant voltage means C■ and applied to each circuit of the fire detector. The environment detection means FS detects the environmental state related to the fire phenomenon and outputs an environment information signal to the signal processing means PR. The signal processing means PR processes the environment information signal from the environment detection means FS to determine a fire, and when it is determined that a fire has occurred, outputs a fire signal to the signal sending means TX. Upon receiving the fire signal from the signal processing means PR, the signal sending means TX transmits the power supply line 11. This state is maintained as a short circuit or low impedance with l12, and in this way a fire signal is sent to the fire reception 11RE.

If the power lines 11, 12 are short-circuited or have low impedance, a fire reception occurs! The relay RL in the IRE is energized and its contact a is closed, which lights up the fire lamp LP to visually indicate the occurrence of a fire.

On the other hand, if a fire occurs and the signal sending means TX is activated and the power line 13.12 is short-circuited or has low impedance, then the power line 13.12 is short-circuited or has low impedance. ．． The voltage across 12 drops, and this voltage drop is detected by the reset means R3 in the fire detector SE. That is, when the reset means R3 detects a voltage value below a predetermined value, it outputs a reset signal to the signal processing means PR to put the signal processing means PR into a stopped state or a standby state, that is, a reset state, The signal processing means PR is prevented from operating under unstable voltage.

After that, when the recovery switch SW is operated to restore the fire operating state and the contacts of the switch SW are temporarily opened, each fire detection signal is transmitted from the power source E of the fire receiver RE via the power lines 11 and e2 The power supply to the device SE is cut off, thereby releasing the hold on the signal sending means TX and restoring the voltage between the power supply lines 11 and 12. The source line! When the voltage across 2.12 is restored and the voltage from the constant voltage means C returns to the normal voltage value, the reset means R3 stops applying the reset signal to the signal processing means PR. The reset state is released and the operation starts from the predetermined steps, in this embodiment, the initial settings. Note that the capacitor C is a capacitor used as a backup power source when the power supply is cut off.

In particular, FIG. 2 is a block circuit diagram showing the signal processing means PR of FIG. 1 in more detail, and other circuit parts other than the power supply circuit or the part between the power supply lines are also shown.

The signal processing means PR includes a microprocessor MPU, a storage area ROM1 containing a program, a storage area ROM2 containing a specific code, and a storage area RA for storing a specific code.
M1, a work area RAM2 used for temporarily storing environmental detection values read from the environment detection means FS, and previous and previous data, respectively, for storing past environmental detection values, that is, data for obtaining difference values. It includes storage areas RAM3 and RAM4 for storage, a counter CM for counting the number of resets, and a timer TM for setting the timing for reading the environment detection value from the environment detection means FS.

Note that the counter CM is not used in the first embodiment explained in FIG. 3, but in the second embodiment explained in FIGS. 4A and 48.
It is used in the case of the embodiment.

FIG. 3 is a flowchart illustrating the first embodiment of the present invention, taking as an example a differential type system in which fire monitoring is performed based on changes in environmental detection values. In this first embodiment, the specific code in the storage area ROM 2 is first stored in the storage area RAM 1 for storing specific codes, and thereafter it is stored in the storage area RAM 1 every time a fire determination is to be made. ,
The submitted specific code is checked or inspected, and a fire judgment is made only if the specific code is normal. If the specific code is defective, a fire judgment is not made. Only the operation of replacing the environmental detection value with the current environmental detection value is performed.

That is, after the initial settings (step 302), the environmental detection values are read (step 304), and the work area RAM2 is
(Step 306), and the environmental detection value is stored in the storage area RAM 3 for storing the previous data and the storage area RAM 4 for storing the data from the time before the previous one (Step 308).
, and the contents of the specific code stored in the specific code built-in storage area ROM2 are stored in the specific code storage storage area R.
A M 1 (step 310), then
When the detected value read timing signal is output from the timer TM (step 312 and Y in step 314), the environmental detected value is read (step 316) and stored in the work area RAM2 (step 318), and the fire judgment is made. Before this, the specific code stored in the storage area RAM1 is checked (step 320).

If the specific code stored in the storage area RAM1 is not destroyed, that is, if the specific code stored in the storage area RAM1 matches the original code stored in the storage area ROM2 (Y in step 322), this time The environmental detection value in the read storage area RAM 2 and the storage area RAM
The difference between the previous environmental detection value in J is calculated (step 324), and a fire determination is made (step 326).

However, due to some reason such as noise, the specific code 2 stored in the storage area RAM 1 is transferred to the storage area ROM.
2 If it does not match the built-in original specific code (Step 3
22N), no fire determination is performed, and an operation is performed to replace the past environmental detection value with the current environmental detection value in order to use it as a reference for future difference value calculation (step 308).
), the specific code is stored in the storage area RAM1 again (step 310).

The specific code in the storage area RA Ml has not been destroyed (Y in step 322), and the difference or differential value between the environmental detection value in the storage area RAM2 and the environmental detection value in the storage area RAM4 is used to make a fire determination. Results (Step 3)
24) If the difference value between the two is smaller than the fire threshold F (N in step 326), the contents of the storage area RAM3 are set as the reference for calculating the difference value.
and the contents of the storage area RAM2 are transferred to the storage area RAM
3 (step 328), and thereafter, the same operation is continued by reading the environmental detection value every time a timing signal is output from the timer TM.

After that, as a result of the fire determination, if the difference or differential value between the current environmental detection value in the storage area RAM2 and the previous environmental detection value in the storage area RAMJ is greater than or equal to the fire threshold F (step 326). Y), a fire signal is outputted from the signal sending means TX to the fire receiving iRE (step 330). For example, in the example of FIG. 1, the power supply line 11.
B is short-circuited or set to low impedance to energize the relay RL in the fire receiver RE and turn on the fire light LP.

When the impedance between the power supply lines 11 and 12 is reduced to low impedance in this way, the output potential of the constant voltage means CV becomes lower than the predetermined potential, so that the reset means R3 is connected to the signal processing means PR.
A reset signal is output to the signal processing means PR to put the signal processing means PR into a reset state.

After that, in order to restore the fire operation, use the recovery switch SW.
When is operated, the holding of the signal sending means PR is released, the short circuit or low impedance state between the power supply lines 11 and 12 is released, the output of the constant voltage means C increases, and the signal processing from the reset means RS is thereby released. The reset signal to the means PR is canceled, and the signal processing means PR enters a state in which the reset state is released. By canceling the reset,
The signal processing means PR resumes its operation from the initial setting shown in step 302 in FIG.

In this way, in the first embodiment explained in FIG.
Since a fire judgment is made after a specific code is memorized and a specific code check is performed, that is, after determining whether or not the specific code is accurately memorized, Memorized records used for fire detection +! The reliability of past data in the areas RAM 3 and RAM 4 can be confirmed, and a reliable fire judgment can be made.

In addition, in FIG. 3, the specific code is written into the storage area RAM1 only once in step 310, and thereafter, the specific code is checked every time a fire determination is to be made in step 322. As well as checking the specific code, write the specific code to the storage area RAM.
Every time I try to update the contents of 3 and RAM 4,
You can also do it. In that case, step 31
0 is.

It may be brought before or after step 328.

In addition, in the fire alarm system whose operation is explained in Fig. 3, as shown in Fig. 1, the fire detector SE sends out a fire signal to the fire receiver RE by shorting the power line or making it low impedance. However, the fire detector may be of the type that transmits a fire signal to the fire receiving IRE in the form of a digital or analog signal without making the power supply line low impedance. In this case, the fire reception fiRE needs to be provided with a circuit configuration that can receive and decode the fire signal from the fire S alarm SE.

4A and 4B are flowcharts showing a second embodiment of the operation of the signal processing means PR for the configuration shown in FIGS. 1 and 2. FIG.

In the first embodiment, the fire receiver R
After sending a fire signal to E, when the fire receiver is restored to its initial state by the restoration operation, the contents of storage areas RAM3 and RAM4, which store past data, are also updated with the newly read environmental detection values. If the contents of storage areas RAM3 and RAM4 are initialized in this way, even if the fire condition continues, the environmental information in the current fire condition will not match the past data. Since this value is set as a reference value and the difference value between the reference value and the currently detected value is calculated, there is a possibility that a change in the environmental state due to a fire cannot be detected, resulting in a false alarm.

Therefore, in the second embodiment, when it is determined that a fire has occurred, the specific code in the storage area ROM 2 is stored in the storage area RAM 2 before outputting the fire signal (step 446).
1 (step 442). When a fire signal is sent out, the voltage of the power supply line decreases, and the signal processing means PR goes into a standby state under the control of the reset means RS.
In other words, it becomes a reset state. Thereafter, the fire operation is restored, the reset state is released, and initial settings are performed.

During this initial setting (step 402), the storage area RAM
The contents of each memory in RAM 1, RAM 3, and RAM 4 are not cleared but are stored as they are. After the environmental detection value is read into the storage area RAM 2 (step 406), a check for the specific code is performed (step 408). The specific code check confirms that the specific code in the storage area RAM 1 is accurately stored. If it is determined that (Y of step 410)
), this means that the specific code was not destroyed while in the reset state, so similarly, the contents of the storage areas RAM3 and RAM4 that store past data values can also be assumed to be reliable. Therefore, from now on, fire determination will be continuously performed based on the past data in the storage areas RAM3 and RAM4 before the reset (steps 416 and 418).

This eliminates the problem of the possibility of misreporting due to data failure.

However, if we assume a differential heat sensor as an example of a fire detector that detects fire based on changes in environmental information, it is possible that a fire signal may be erroneously output due to non-fire factors such as heating. If a false fire signal is output in this way, the fire receiver RE will alert the fire detector SE.
It is necessary to forcefully restore the system.

In this way, the reset state of the signal processing means PR is forcibly restored and the deaf state is canceled, and the operation from the initial setting (step 402) is performed to check the specific code.Step 408
), if the specific code is normal (step 41
0 Y), the contents of storage areas RAM3 and RAM4 are not rewritten, but if the ambient temperature rises further due to heating etc., the values of past data in storage area RAMJ and the memory read this time The difference with the value in area RAM2 becomes even larger (Y in steps 416 and 418), and a non-fire alarm is issued again (step 420). This also allows fire reception fi
A forced recovery from RE is performed and the operation is performed from the initial settings, but similarly, if the specific code is normal (Y in step 410), the contents of the storage areas RAM3 and RAM4 will not be updated. If the ambient temperature is rising, the difference value will be even larger, and in this way the fire receiver R
It is conceivable that no matter how many recovery operations are performed from E, the fire detector SE will immediately output a fire signal, making recovery operations impossible.

In order to solve this problem, a counter CM is provided in the signal processing means PR, and the counter CM counts the number of times a specific code is determined to be normal after initial setting (Step 412), and the counter CM counts the number of times a specific code is determined to be normal after initial setting. If X is reached (
Y in step 414), clear the specific code in the storage area RAM1 (step 424), update the contents of the storage areas RAM3 and RAM4 with the environmental detection value in the storage area RAM2 read this time (step 426), and then
By the timing signal from the timer TM (step 42
8 and 430), and fire determination is performed (steps 432 to 440). As described above, if a fire occurs thereafter (Y in step 438), a specific code is written to the storage area RAM1 to confirm the reliability of the stored data after recovery (step 442).
), the counter CM is reset (step 444),
Thereafter, a fire signal is output (step 446) and after a recovery operation from the fire receiver RE, step 40
The operation from the initial setting in step 2 is performed.

In the embodiment shown in FIGS. 4A and 4B, a specific code check may be performed before the fire determination (step 436), as in the embodiment shown in FIG. Steps corresponding to steps 320 and 322 in FIG. 4B are placed between steps 434 and 436 in FIG.
6, and if the specific code fails as a result of the specific code check, the process returns to step 426 and the storage areas RAM3a and RAM4 are
It starts with the operation of updating with the current environmental detection value in M2. At this time, it is also possible to use a specific code different from the specific code of the step corresponding to step 310 and the specific code of step 442.

[Effects of the Invention] As described above, according to the present invention, a specific code is stored in a random access memory, and it is determined whether or not this code is accurately stored. This has the effect of being able to confirm the reliability of the stored data.

In addition, in the event of a fire, a specific code is written before resetting, and after the reset is released, the presence or absence of the specific code is checked, and if the specific code exists or is normal, We have made it possible to make continuous fire judgments based on the environmental information before the reset.
For example, in a fire detector that detects a fire based on a change value or a difference value of environmental information, there is an effect that reliable fire monitoring can be performed even after the reset is released.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing a fire detector according to an embodiment of the present invention, FIG. 2 is a block circuit diagram specifically showing the inside of the signal processing means of FIG. 1, and FIG. 4A and 4B are flowcharts for explaining the second embodiment of the operations shown in FIGS. 1 and 2. ,
It is. In the figure, RE is a fire receiver, SE is a fire alarm, and F
S is an environment detection means, PR is a signal processing means, RS is a reset means, TX is a signal sending means, MPU is a microprocessor, ROM 1 is a storage area containing a program, ROM
2 is a J storage area with a built-in specific code, RAM 1 is a storage area for writing specific codes, RAM 2 is a ft business area,
RAM3 and RAM4 are storage areas for past data, C
M is a counter and TM is a timer. Figure 4A

Claims (2)

[Claims] (1) An environmental detection means that detects the environmental state related to a fire phenomenon and outputs an environmental detection value, and stores the environmental detection value from the environmental detection means in a storage means over time and processes the signal at a predetermined period to detect a fire. A fire detector comprising a signal processing means for performing discrimination, a writing means for writing a specific code into the storage means, and a writing means for writing a specific code into the storage means each time the signal processing means attempts to perform the signal processing. a checking means for checking the specific code stored therein and initializing the contents of the storage means if the content of the specific code is determined to be abnormal; vessel. (2) An environmental detection means for detecting an environmental state related to a fire phenomenon and outputting an environmental detection value; and in a fire monitoring state, storing the environmental detection value from the environmental detection means in a storage means over time and subjecting it to signal processing. a signal processing means for detecting a fire;
and a reset means for outputting a reset signal to reset the signal processing means when the signal processing means determines that a fire has occurred as a result of the fire discrimination, and when the signal processing means enters the reset state. In the fire detector which can return to the fire monitoring state by canceling the reset state, when the signal processing means determines that a fire has occurred, a specific code is written in the storage means before entering the reset state. and a writing means for checking the specific code written in the storage means after the reset state of the signal processing means is released, and if it is determined that the content of the specific code is abnormal; A fire detector comprising: confirmation means for initializing the contents of the storage means;