JPH0228797A - Fire alarm device - Google Patents

Abstract

PURPOSE:To obtain a fire alarm device which is of simple device constitution and is easy for a test operation by performing the detection of a fire, the detection of disconnection and the test operation in common for every sensor line by selecting the sensor line successively. CONSTITUTION:At usual time, by operating a selection circuit 8 so as to select the sensor lines 2a-2n successively, the fire detection and the disconnection detection are performed in common for every line 2a-2n. Therefore, circuit constitution can be extremely simplified. Besides, at the time of a test, s switch 12 is operated during the successive selection of the lines 2a-2n by the selection circuit 8, and the lines 2a-2n are short-circuited to low impedance through artificial line resistance 13. A that time, the test operation is performed by deciding whether a fire detection output can be obtained normally from a detection circuit 9 or not. Therefore, since the line is selected automatically at the time of the test, the test operation becomes easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fire alarm device that performs fire, disconnection, and test operations for each sensor line connected to a receiver with a simple circuit configuration.

[Prior Art] Conventionally, the detection of a fire or a disconnection state in a receiver of a fire alarm system involves a fire detection circuit that detects the alarm current flowing in each sensor line when the sensor fires, and a fire detection circuit that detects the alarm current that flows when the sensor fires, and a fire detection circuit that detects the alarm current that flows when the sensor generates an alarm, and a fire detection circuit that detects the alarm current that flows when the sensor generates an alarm. Each is provided with a disconnection detection circuit for detecting current.

In addition, in the test equipment, multiple detector lines connected to the fire receiver are sequentially selected by operating a test rotary switch installed in the receiver, and a pseudo line resistance is applied to the detector lines via the rotary switch. By connecting this and short-circuiting it to a low impedance, we create a pseudo reception condition similar to when a fire detector fires, and test whether the reception operation is performed normally.

[Problems to be Solved by the Invention] However, in such conventional fire alarm devices, the receiver has a fire detection circuit and a disconnection detection circuit for each sensor line, so the circuit configuration is complicated. There was a problem that the receiver itself became larger due to the increase in the number of lines.

In addition, in the test equipment, the sensor line is selected and tested by operating a rotary switch, so the wiring connection to the rotary switch is complicated, and if it is installed for a long time, it may not be used often. Due to the small number of lines, some lines may not be able to perform the test due to faulty rotary switch contacts.Furthermore, the test operation is complicated because the rotary switch is used for manual selection.Furthermore, as the number of lines increases, multiple rotary switches are required. Therefore, there were problems in that it became large and difficult to use.

The present invention has been made in view of these conventional problems, and it sequentially selects sensor lines and performs fire detection, disconnection detection, and test operations for each sensor line in common, thereby improving device configuration and testing. To provide a fire alarm system that is easy to operate and inexpensive.

[Means for Solving the Problems] In order to achieve this object, the present invention includes a selection means for sequentially selecting a plurality of sensor lines for each caution area to which fire detectors are connected; a detection means commonly provided to each sensor line for detecting a fire state and a disconnection state of the sensor line; a switching means for short-circuiting the sensor line to a low impedance via a pseudo line resistance; The selection means is operated to detect a fire or disconnection state for each sensor line, and at the time of testing, the switching means is turned on and the selection means is operated to perform a test operation for each sensor line. A control means is provided.

[Function] In the test device of the present invention having such a configuration,
During normal times, fire and disconnection detection can be performed commonly for each sensor line by operating the selection means and selecting the sensor lines one after another. This eliminates the need for fire detection circuits and disconnection detection circuits, which greatly simplifies the circuit configuration, making it possible to downsize and reduce costs.

Furthermore, during the test, the switching means is operated while the selection means sequentially selects the sensor lines to short-circuit the sensor lines to a low impedance via the pseudo line resistance, and at this time the fire detection output is normally obtained from the detection means. Since the test operation can be performed by determining whether or not the The test operation is easy because the selection means is always operating, so even if it is installed for a long time, there will be no test failure due to contact failure like with rotary switches, and reliability is high. expensive.

[Embodiment] FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

In FIG. 1, 1 is a fire receiver, and the fire receiver 1
From then on, sensor lines 2a, 2b, ... 2n are installed in each caution area.
A pair of sensor lines consisting of each of the sensor lines 2a to 2n and the common line 3 are drawn out, and one or more fire detectors 4 are connected between each of the sensor lines 2a to 2n and the common line 3. A terminating resistor 5 for detecting disconnection is connected to the end of the sensor line.

The detector lines 2a to 2n are commonly connected within the fire receiver 1 via a resistor 6, and the power supply within the receiver (
+) side.

8 is a selection circuit, which includes analog switches SL, S2 . ...Sn, the sensor lines 2a to 2n for the resistor 6 are branch-connected to one end (right side) of the analog switches 81 to Sn, and the other ends of the analog switches 81 to Sn are commonly connected. The selection circuit 8 including the analog switches 81 to Sn is
The operation of sequentially turning on the analog switches S100-Sn at regular intervals is repeated, and the sensor lines 2a-2n are selectively connected to the common connection side of the analog switches 81-Sn. The selection output of the selection circuit 8, that is, the analog switch 81~
The common connection output of Sn is given to the detection circuit 9, and the detection circuit 9 detects a fire or disconnection of the sensor line selected by the selection circuit 8. Fire detection by the detection circuit 9 is as follows.

Assuming that the power supply voltage for the sensor lines 2a to 2n of the fire receiver 1 is, for example, 24V, and the line resistance of each of the sensor lines 2a to 2n is R1, R2,...Rn, each detection for the selection circuit 8 in the steady monitoring state is The input voltage of the device line is determined by the resistance value of the terminating resistor 5 since the resistor 6 and the line resistances R1 to Rn are sufficiently small compared to the terminating resistor 5. For example, the input voltage of the line is determined by the resistance value of the terminating resistor 5. It is around 23V. With respect to the line voltage of each sensor line 2a to 2n for the selection circuit 8 in such a steady monitoring state, for example, the fire detector 4 installed in the sensor line 2a detects a fire, and the sensor line 2a and the common line 3 When short-circuited between them to a low impedance, the input voltage of the sensor line 2a to the selection circuit 8 is reduced to approximately 0. Therefore, when the sensor line 2a is selected by turning on the analog switch S1 of the selection circuit 8, the detection circuit 9 detects the line voltage that has dropped to approximately OV and produces a fire detection output.

On the other hand, in the disconnection detection in the detection circuit 9, for example, if the sensor line 2a is disconnected, the input voltage of the sensor line 2a to the selection circuit 8 will rise from 21 to 23 V in the steady monitoring state to the power supply voltage of 24 V. The detection circuit 9 detects the increased line voltage of 24 V when the analog switch S]- of the selection circuit 8 is turned on, and generates a disconnection detection output.

Reference numeral 10 denotes a CPU, which performs storage reception in the fire receiver 1 of this embodiment, and thus has a control function for storage reception and a control function for a fire test that will be explained later. The CPU 10 also includes a test switch 15.
, a storage reception release switch 16, a fire light 17, an abnormality indicator light 18, a district light 20, a key switch 21 used for individual fire tests, and a line display section 22 are connected.

Between the selection circuit 8 and the detection circuit 9, there is a switching circuit 11 for storage reception by the CPU10, and a
Switching circuit 1 for performing test operation by l0
2 is provided. Switching circuit 1 for storage reception
1 is connected between the signal line between the selection circuit 8 and the detection circuit 9 and the ground, while the switching circuit 1 for testing
2 is approximately - to the line resistance R1 to Rn of the sensor lines 2a to 2n.
It is connected to ground via a corresponding pseudo line resistor 13.

Here, the storage reception function of CPU10 will be explained as follows. For example, assume that a fire is detected by the fire detector 4 connected to the sensor line 2a, and the sensor line 2a and the common line 3 are short-circuited to a low impedance. When the analog switch S1 of the selection circuit 8 is turned on in the alarm state from the sensor line 2a, the line voltage of the sensor line 2a to the detection circuit 9 drops to approximately O■, and this drop in line voltage is detected. The fire detection output is CPU i O
given to. Upon receiving the fire detection output from the detection circuit 9, the CPU 10 temporarily stops the operation of the selection circuit 8 and locks the analog switch S1 corresponding to the sensor line 2a in the on state. Next, the CPU 1O switches to the switching circuit 11.
is turned on to short-circuit the sensor line 2a which has issued an alarm via the analog switch S1 of the selection circuit 8 to a low impedance.
The power supply to the detector line 2a is cut off to restore the fire detector 4 that has issued the alarm. The switching circuit 11 is turned off again by the control signal of the CPU10 after a sufficient time has elapsed for the fire detector 4 to recover from the alarm. Next C
PU10 causes the selection circuit 8 to start operating again. When the fire detection output from the sensor line 2a is again obtained from the detection circuit 9 within a certain period of time after the switching circuit 11 is turned off, the CPU 10 issues a fire alarm and displays a fire indication using the fire light 17 and the corresponding district light 20. Do this.

The storage function is automatically canceled by this fire alarm, and the next alarm will be displayed on the sensor line immediately without storage. Further, the storage function can be canceled in the steady monitoring state by operating the storage function release switch 16.

On the other hand, the control function for the test operation by the CPU 10 is as follows:
Analog switch 81 of selection circuit 8 in steady monitoring state
When a test operation is commanded to the CPU U i O by operating the test switch 15 during the selection operation by sequentially turning on Sn, the CPU 10 sets the test mode and automatically cancels the storage reception function. switching circuit 1
2 is turned on, and the pseudo line resistor 13 is connected to the output of the selection circuit 8.

Assuming that the sensor line 2a is selected by turning on the analog switches 81 to Sn in sequence after the operation of the switching circuit 12, for example, by turning on the analog switch S1, the sensor line 2a is set to the test line that is in the on state. The switching circuit 12 is short-circuited to low impedance by the dummy line resistance 13 in the same way as when a fire is detected, and if the system of the sensor line 2a is normal, the input voltage to the detection circuit 9 is the same as when a fire is detected. , decreases to approximately 0■, the detection circuit 9 outputs a fire detection output to the CPU10, and the CPU10 confirms that the fire detection output is obtained from the detection circuit 9 and determines that the sensor line 2a is normal. Then, the test operation moves on to the next sensor line 2b, and the test operation is performed sequentially in the same way, and when the test operation is completed up to the sensor line Sn, the storage reception function is automatically restored, and the switching circuit 12
will turn off and return to steady monitoring status.

In addition, during the test, the ringing of the alarm bell and the interlocking control of various disaster prevention devices when a fire is received by the CPU10 are automatically canceled, and only the fire light 17 and the district light 20 corresponding to the test line are displayed and operated. You may also do so.

Next, the operation according to the embodiment of FIG. 1 will be explained with reference to the operation flow diagram of FIG. 2.

First, when the fire receiver 1 is powered on, a control signal is given from the CPU 10 to the selection circuit 8, and as shown in step S1, the analog 0 switches 81 to S provided in the selection circuit 8 are activated.
The sequential selection of the sensor lines 2a to 2n is started by the sequential on-scanning of the sensor lines 2a to 2n.

With a specific sensor line selected through this line sequential selection, the process advances to step S2 to check whether or not a fire has been detected.If a fire detection output is obtained from the detection circuit 9, the process advances to step S3 to issue a fire alarm. At the same time, the fire light 17 and the district light 17 corresponding to the sensor line that issued the alarm are turned on to indicate that the fire has been received.

Of course, the fire detection in step S2 is performed by the CPU10 described above.
These are the results obtained by storage reception processing based on on/off control of the switching circuit 11 according to the present invention.

Next, in step S4, it is checked whether there is a disconnection. If a disconnection detection output is obtained from the detection circuit 9, the process proceeds to step S5, where the abnormality indicator lamp 18 is turned on to indicate a disconnection, and at the same time, the corresponding district light 20 is turned on.

Next, in step S6, it is checked whether the test switch 15 is on or off, and if the test switch 15 is off, the process returns to step S1 and the next sensor line is selected, and the fire detection and disconnection detection processes are performed in the same manner. repeat.

On the other hand, if the test switch 15 is turned on to perform a test in the steady monitoring state, it is determined in step S6 whether the test switch 15 is on, and the process proceeds to step S7, where a test mode is set.

In setting the test mode in step S7, the storage reception function of the CPU 10 is automatically canceled in order to speed up the fire reception during the test and shorten the test time.

Furthermore, when setting the test mode in step S7, the ringing control of the alarm bell of the fire receiver 1 and the interlocking control of various disaster prevention devices may be canceled for testing purposes.

However, if a fire alarm is issued through one sensor line, the storage function will be automatically canceled.

Next, proceeding to step S8, the CPU I O turns on the switching circuit 12 for testing, and short-circuits the sensor line selected by the selection circuit 8 to a low impedance via the pseudo line resistor 13 for testing.

When the test switching circuit 12 is turned on in step S8, the process proceeds to step S9, where it is checked whether a fire detection output is obtained from the detection circuit 9 for the specific sensor line selected by the selection circuit 8 at that time. However, if a fire detection output is obtained, the process proceeds to step S10 and the fire light 17 is turned on.
And the corresponding district lights 20 are used to indicate the fire. On the other hand, if the fire detection output is not normally obtained, step S1
Proceeding to step 1, an abnormality is displayed by lighting the abnormality indicator lamp 18.

Next, the process advances to step S12 to check whether or not the testing of all lines has been completed. If the testing of all lines has not been completed, the process advances to step S13 where the next sensor line is selected by the selection circuit 8. Returning to step S9 again, the process of checking whether or not a fire has been detected is repeated.

Note that the indicator light may be turned off automatically by a timer or the like when a fire indication is given by the test in step SIO, or may be done manually by operating a test recovery switch (not shown).

When it is determined in step S12 that the test for all lines has been completed, the process advances to step S14 to complete the test.

That is, the test mode set in step S7 is canceled (by turning off the test switching circuit 12 and returning the storage reception function, etc.), and returns to step S1 again to enter normal fire monitoring processing.

The objects to be checked by such test processing are the selection circuit 8 to the detection circuit 9 for the detector lines 2a to 2n in the fire receiver 1, as well as the line system leading to the CPU10, the selection circuit 8, and the detection circuit 9. In particular, an important item is testing whether the analog switches 81 to Sn provided in the selection circuit 8 which sequentially selects the sensor lines 2a to 2n operate normally.

In the above embodiment, when a test operation is commanded to the CPU10, the selection circuit 8 sequentially selects the sensor lines 2a to 2n to perform the test operation.
An individual fire test is also possible in which a test operation is performed on a specific sensor line by giving an operation input to the CPU 10 that specifies a specific sensor line as the test target.

This individual fire test can be conducted as follows.

In the steady monitoring state, the selection circuit 8 switches the analog switches 81 to S.
During the operation of sequentially turning on n, select the sensor line to be tested using the key switch 21 such as a numeric keypad. The line selected by the key switch 21 is displayed on the line display section 22 using a 7-segment LED, etc., so the test line is selected by the key switch 21 while checking the displayed line. Next, by operating the test switch 15, the CPU
Set the test mode to 10, and set the test mode to C.
The P U 10 operates the switching circuit 12 only at the timing when the sensor line selected as a test target is selected by the selection circuit 8, thereby making it possible to perform a fire test on only a specific sensor line. key switch 2
1, other than the numeric keypad, a shift key or the like may be used that increases or decreases the displayed number by one each time the key is operated.

After the test is completed, the test mode is canceled and the steady monitoring state is restored as in the case of all line tests.

FIG. 3 is a circuit block diagram showing another embodiment of the present invention.

In the embodiment shown in FIG. 1, a switching circuit 12 for fire testing and a pseudo line resistance 13 are provided between the selection circuit 8 and the detection circuit 9, but in the embodiment shown in FIG. is directly connected to all the sensor lines 2a to 2n via the pseudo line resistor 13 and the loop prevention diode 23.

Therefore, in the automatic fire test for all lines in the embodiment shown in FIG. 8, the sensor lines are sequentially selected and a fire test is performed.

This point is the same for the individual fire test, and the switching circuit 12 is turned on only at the selection timing of the sensor line selected as the test target by the selection circuit 8, and all the sensor lines 2a to 2n are connected to the pseudo line resistance 13. Short to low impedance through.

The configuration and operation other than the switching circuit 12, the pseudo line resistor 13, and the loop prevention diode 23 are the same as those of the embodiment shown in FIG.

In the above embodiment, a fire receiver having a storage reception function was used as an example, but the test device of the present invention can be similarly applied to a case that does not have a storage reception function. can.

Furthermore, the district lights 20 for each line that were turned on during the test are not turned off at the end of the test but remain lit so that the district lights can be reconfirmed after the test. ) to turn off the light.

On the other hand, since the test data is stored in the memory 14 of CPU10, the test results may be confirmed by printing out the data after the test is completed.

[Effects of the Invention] As explained above, according to the present invention, by operating the selection means and sequentially selecting the sensor lines during normal times,
Since fire detection and disconnection detection can be performed commonly for each sensor line, there is no need for a fire detection circuit and disconnection detection circuit for each sensor line as in the past, greatly simplifying the circuit configuration. It is possible to achieve miniaturization and cost reduction.

Furthermore, during the test, the switching means is operated while the selection means sequentially selects the sensor lines to short-circuit the sensor lines to a low impedance via the pseudo line resistance, and at this time the fire detection output is normally obtained from the detection means. Test operations can be performed by determining whether or not the Since the selection means is always in operation, even if it is installed for a long time, there will be no test failure due to contact failure like with rotary switches, and the reliability is high.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing one embodiment of the present invention; FIG. 2 is an operation flow diagram showing a test operation according to the embodiment of FIG. 1; FIG. 3 is a circuit block diagram showing another embodiment of the present invention. FIG. 3 is a circuit block diagram. 1: Fire receivers 2a to 2n Detector line 3 Common line 4: Fire detector 5: Terminal resistor 6/resistor 76 Common recovery switch 8 Selection circuit 9: Detection circuit 10: CPU (accumulation control means) 11 Switching circuit (fire (for detection) 12, Switching circuit (for testing) 13 Pseudo line resistance 14 Memory R1 to Rn two line resistance 15 Test switch: Accumulation release switch: Fire light: Abnormality indicator light, district light: Key switch: Line display section: Wraparound prevention diode for

Claims (1)

[Claims] 1. Selection means for sequentially selecting a plurality of sensor lines for each warning area to which fire detectors are connected; detecting a fire state and disconnection state of the sensor line selected by the selection means; Detection means provided in common to each sensor line; Switching means for short-circuiting the sensor line to low impedance via a pseudo line resistance; Normally, the selection means is operated to detect a fire for each sensor line. and a control means for detecting a disconnection state, turning on the switching means and performing a test operation for each sensor line by operating the selection means during the test. Device.