JP2004302966A - Fire receiver and status detecting program for external instrument for fire receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect the various statuses of an external instrument such as an emergency broadcasting facility even when a power supply voltage fluctuates in simple and inexpensive configurations. <P>SOLUTION: This fire receiver is provided with a virtual short circuit 52 for setting an external instrument connecting terminal T<SB>2</SB>of external instrument connecting terminals T<SB>1</SB>and T<SB>2</SB>to which an emergency broadcasting facility 24 is connected in a virtual short circuit status. Furthermore, this fire receiver is provided with a condition detecting circuit 37 for detecting the status of the emergency broadcasting facility 24 and a control part 31 for detecting an A value from the status detecting circuit 37 when the virtual short circuit status is set by the virtual short circuit 52, and for detecting a B value from the status detecting circuit 37 when the virtual short circuit status is not set by the virtual short circuit 52, and for deciding the short circuit status between the external instrument connecting terminals T<SB>1</SB>and T<SB>2</SB>, a disconnecting status between at least one of the external instrument connecting terminals T<SB>1</SB>and T<SB>2</SB>and the emergency broadcasting facility 24, the operating status of the emergency broadcasting facility 24 and the non-operating status of the emergency broadcasting facility 24 based on a C value being the result of the division of the B value by the A value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fire receiver provided with a function of detecting a state of an external device such as an emergency broadcast facility, and a program for detecting a state of the external device in the fire receiver.
[0002]
[Prior art]
Many buildings constructed in recent years have a fire alarm system. In this fire alarm system, when a fire detector detects a fire and outputs a fire detection signal, a fire receiver, which is a control panel, receives the fire detection signal and displays that a fire has occurred. A sound device such as a bell is sounded to notify people in the building. Also, some conventional fire receivers have a function that works in conjunction with emergency broadcast equipment connected as an external device, and when a fire detection signal is received from a fire detector, this emergency broadcast equipment is activated. Then, a voice message is used to alert the user of the fire or to evacuate them.
[0003]
However, if the emergency broadcast facility is operated simultaneously with the ringing of the district bell, the voice message from the emergency broadcast facility becomes difficult to hear due to the ringing of the district bell, so it is necessary to stop the ringing of the district bell. Therefore, as shown in FIG. 5, the conventional fire receiver 1 is provided with a local sound ringing stop device 5, and when the microphone switch 12a of the emergency broadcast equipment 12 is pressed, the local sound ringing stop device is provided. 5 drives the relay control circuit 15 to open the control contact 14, thereby interrupting the supply of power to the district bell 7 and stopping the ringing of the district bell 7 (for example, see Patent Document 1). 1).
[0004]
[Patent Document 1]
JP-A-10-134263 (pages 1-3, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, the above-mentioned conventional fire receiver 1 merely detects the ON / OFF state of the microphone switch 12a, and the disconnection state of the signal lines 11A and 11B and the short circuit between the emergency broadcast equipment connection terminals 13. Other states, such as states or intermediate states, cannot be detected. For this reason, when the signal line 11A or the signal line 11B is disconnected, the ringing of the district bell 7 is stopped at the time of a fire and an emergency broadcast cannot be performed. The emergency broadcast facility connection terminals 13 are short-circuited. In this case, there is a possibility that the area bell 7 does not ring and malfunctions. In addition, some users of the fire receiver 1 request that the state of the emergency broadcast facility 12 be detected more accurately, but the above-described conventional fire receiver 1 can meet such a demand. Can not.
[0006]
Further, the above-mentioned conventional fire receiver normally rectifies a commercial power supply of 100 V by a power supply circuit to generate a DC voltage of a predetermined voltage, and supplies the DC voltage to each unit. The AC voltage value of the commercial power supply fluctuates according to the demand for the power supply, for example, in summer or winter when air conditioners and the like are used all at once. Further, the fire prevention law requires that the fire receiver be provided with a battery. However, the output voltage value of this battery decreases due to spontaneous discharge or aging.
[0007]
However, as shown in FIG. 5, the conventional fire receiver 1 described above has a fuse 4, a district acoustic relay 3A, and one output line 2A of a two-wire district acoustic output line 2 between the power supply and the ground. The power supply line 6A, the relay 15a of the relay control circuit 15, and the noise preventing capacitor 17 are connected in series and inserted. Therefore, since it is directly affected by the fluctuation of the power supply voltage, even if the microphone switch 12a is pressed at the time of a fire, there is a possibility that the ringing of the district bell 7 is stopped and an emergency broadcast cannot be performed.
[0008]
In this regard, it is conceivable to configure the power supply circuit as a circuit that is not affected by power supply fluctuations, or to use a high-precision relay 15a and noise prevention capacitor 17, but in that case, the local sound ringing stop device is used. Price of 5 becomes high. The inconvenience described above occurs not only when the emergency broadcast facility 12 is connected to the fire receiver 1 but also when other external devices are connected to the fire receiver 1.
[0009]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object a simple and inexpensive configuration to accurately detect various states of an external device even when the power supply voltage fluctuates. The present invention is to obtain a fire receiver that can be detected and a state detection program of an external device in the fire receiver.
[0010]
[Means for Solving the Problems]
In order to solve the above problem, a fire receiver according to the present invention has a virtual short circuit for setting a virtual short circuit between two terminals to which an external device is connected, and A first voltage value is detected from the state detection circuit when the virtual short circuit is set by the virtual short circuit, and the virtual short circuit is not set by the virtual short circuit. When a second voltage value is detected from the state detection circuit, a short-circuit state between the two terminals, a state between at least one of the terminals and the external device based on the first and second voltage values. And a control unit for determining a disconnection state, an operation state of the external device, and a non-operation state of the external device.
[0011]
According to a second aspect of the present invention, there is provided the fire receiver according to the first aspect, wherein the external device includes a microphone switch, and is an emergency broadcast facility for performing a fire notification and evacuation guidance by a voice message. When the microphone switch is pressed, a first output voltage value is output, and when the microphone switch is not pressed, a second output voltage value is output.
[0012]
According to a third aspect of the present invention, a program for detecting a state of an external device in a fire receiver causes a computer to function as the control unit according to the first or second aspect.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 2 is a block diagram showing a configuration of a fire alarm system to which the fire receiver 21 according to the embodiment of the present invention is applied.
The fire alarm system of this example includes a fire receiver 21, a plurality of district bells 22, a plurality of fire detectors 23, and an emergency broadcast facility 24.
The fire receiver 21 is installed in, for example, a management room of a building, and has a fire alarm control function, a state detection function of external devices, various test functions, and the like.
[0014]
The fire alarm control function is to supply a fire detection signal from the fire detector 23 installed on each floor of the building to display a fire occurrence area on the display unit 39, activate the sound unit 38, This is a function for issuing a warning of a fire that has occurred, such as sounding the district bell 22 at a relevant location. The function of detecting the state of the external device includes a state in which the microphone switch SW (see FIG. 1) constituting the emergency broadcast facility 24 connected as the external apparatus is pressed (the operation state of the emergency broadcast facility 24), a state outside the fire receiver 1. Device connection terminal T ₁ Or T ₂ (See FIG. 1) and the disconnection state of the signal line connecting the emergency broadcast facility 24 and the external device connection terminal T ₁ And external device connection terminal T ₂ And a non-operating state of the emergency broadcast facility 24 (a normal state in which the microphone switch SW is not pressed). Among them, the emergency broadcast state (the operation state of the emergency broadcast equipment 24) is such that when a fire occurs, the above-mentioned microphone switch SW is depressed by an administrator or the like, so that a previously created voice message or a live message of the administrator or the like is generated. This is a state where a fire is reported from emergency speakers (not shown) arranged in various places by voice and evacuation is guided.
[0015]
Various test functions include, for example, a remote test function and a fire test function. The remote test function means that instead of the operator bringing the heat source close to the fire detector 23 on a trial basis, the fire detector 23 activates its own function and whether or not these normally output a fire detection signal. This is a function for confirming whether or not the output fire detection signal is normally transmitted to the fire receiver 21. On the other hand, the fire test function is to determine whether or not the fire detection signal is artificially supplied from the selected line in the fire receiver 21 and whether or not the device itself is operating normally. Is a function for confirming whether a function for displaying that a fire has occurred and a function for setting data such as display contents are operating normally. Here, the line refers to a place where the fire detector 23 is installed. For example, a plurality of fire detectors 23 arranged at various places on the first floor belong to one line and a plurality of fire detectors arranged at various places on the second floor. The detectors 23 belong to two lines, and the plurality of fire detectors 23 arranged at various places on the n (n is a natural number) floor belong to the n lines.
[0016]
Each district bell 22 is installed at each location on each floor of the building, and when an operating current is supplied from the fire receiver 21, the bell 22 sounds to notify a visitor in the building of the occurrence of a fire. Each fire detector 23 senses that a fire has occurred in a thermal manner, such as a temperature sensor, or detects that a fire has occurred in a smoke manner, such as a photoelectric sensor or an ionization sensor. Or detects that a fire has occurred in a flame, such as an infrared sensor or an ultraviolet sensor, and outputs a fire detection signal. The emergency broadcast facility 24 has a microphone switch SW whose circuit configuration will be described later, and outputs a signal for stopping the ringing of the district bell while the microphone switch SW is pressed.
[0017]
The fire receiver 21 includes a control unit 31, a program memory 32, a work memory 33, a data memory 34, and a district bell drive circuit 35. ₁ ~ 35 _n And the fire detection circuit 36 ₁ ~ 36 _n , A state detection circuit 37, a sound unit 38 also serving as a main sound device, a display unit 39, an operation unit 40, a communication circuit 41, and a handset 42. The control unit 31 includes a microprocessor (MPU) and executes various programs stored in the program memory 32 to execute the above-described fire alarm control function, emergency broadcast function, various test functions, and the like. It controls the inside of the receiver 21 and the entire fire alarm system. That is, for example, taking the state detection function of an external device as a feature of the embodiment of the present invention as an example, the state detection program of the external device is read from the program memory 32 and read into the control unit 31, and the control unit 31 31 is controlled. When the state detection program of the external device is started, the control unit 31 executes a state detection process of the external device described below under the control of the state detection program of the external device.
[0018]
The program memory 32 includes a semiconductor memory such as a PROM, an EPROM, an EEPROM, or a flash memory, and stores in advance various programs to be executed by the control unit 31 described above. The work memory 33 is formed of a semiconductor memory such as an SRAM or a DRAM, and is used as work when the control unit 31 executes the various programs described above. The data memory 34 includes a semiconductor memory such as a PROM, an EPROM, an EEPROM, or a flash memory, and stores initial data necessary for the entire fire alarm system to operate in an initial operation state, or is set by an operator. Various data are stored.
[0019]
District Bell Drive Circuit 35 ₁ ~ 35 _n Supplies an operating current to the corresponding district bell 22 when selected from the control unit 31. Fire detection circuit 36 ₁ ~ 36 _n When the fire detection signal is supplied from the corresponding fire detector 23, the control unit 31 is notified of this. Under the control of the control unit 31, the state detection circuit 37 constantly monitors the above-mentioned emergency broadcast state, short-circuit state, disconnection state, and normal state. The circuit configuration of the state detection circuit 37 will be described later. The sound unit 38 is provided by notifying the occurrence of a fire with an alarm or voice or performing a state detection function of an external device based on an acoustic signal supplied by the control unit 31 executing the fire alarm control function. The occurrence of an abnormality is notified by an alarm or a sound based on the abnormal signal. Although not shown, the display unit 39 includes a plurality of display lamps including a light emitting diode (LED), a light bulb, and the like.
[0020]
The operation unit 40 includes a selection switch (not shown) for selecting a function such as “storage release”, “test recovery”, or “fire test” during maintenance setting, an execution switch for executing the selected function, A main sound stop switch to stop the alarm sound, an abnormal alarm sound stop switch, a regional sound stop switch to temporarily stop the sounding of the district bell, a fire recovery switch to restore the normal monitoring state from the fire / accumulation state Etc., and are operated by an administrator or a worker. The communication circuit 41 processes an audio signal transmitted over a communication line (not shown) and an audio signal supplied from the handset 42 under the control of the control unit 31 to control the control room in which the fire receiver 21 is installed. A manager who is stationed at the office and operates the handset 42 is made to talk to the resident in each place of the building.
[0021]
Next, the configuration of the state detection circuit 37 constituting the fire receiver 21 and the configuration of the emergency broadcast facility 24 will be described with reference to the circuit diagram shown in FIG. The state detection circuit 37 includes a PNP-type bipolar transistor Q ₁ ~ Q ₃ And the resistance R ₁ ~ R ₉ And the capacitor C ₁ , A surge absorber SA, and a Zener diode ZD. Transistor Q ₁ And Q ₂ And resistance R ₁ And R ₂ Constitutes a current limiting circuit 51 and has a DC power supply voltage V generated from a 100 V commercial power supply. _CC (For example, 24 V) and the external device connection terminal T ₁ Is inserted between. The current limiting circuit 51 has a function of preventing an excessive current from flowing to other circuit elements constituting the emergency broadcast facility 24 and the state detection circuit 37. Note that the current limiting circuit 51 may be configured by a fuse.
[0022]
The surge absorber SA is composed of, for example, a discharge gap, a carbon arrester, or a varistor made of Si, SiC, ZnO, or the like. The surge absorber SA protects the state detection circuit 37 from static electricity charged by a manager who presses the microphone switch SW constituting the emergency broadcast equipment 24 or high voltage applied due to occurrence of lightning. Resistance R ₃ Has one end connected to the external device connection terminal T ₂ And used for current limiting. Resistance R ₄ And R ₅ Is the resistance R ₃ Voltage V that appears at the other end of _D Is divided by a predetermined division ratio to obtain a divided voltage V _DD Generate Capacitor C ₁ Is the divided voltage V _DD Noise contained in the divided voltage V _DD Is to stabilize. Resistance R ₆ Restricts the current input to the control unit 31 so that the divided voltage V _DD1 Supply.
[0023]
As described above, the control unit 31 includes, for example, an MPU, has an AD converter as an interface therein, and has an analog divided voltage V _DD1 Is converted into digital divided voltage data, and based on the value of the divided voltage data, an external device state detection process described later is executed. When executing the state detection processing of the external device, the control unit 31 transmits the control signal S _C Is output. The transistor Q constituting the state detection circuit 37 ₃ And the resistance R ₇ ~ R ₉ Constitutes the virtual short circuit 52, and the control signal S supplied from the control unit 31 _C While the external device connection terminal T is at the “L” level. ₁ And external device connection terminal T ₂ Is temporarily set to a virtual short-circuit state. That is, although the details will be described later, the detection voltage V _D To the external device connection terminal T ₁ , T ₂ It is set to the voltage that is input with the short circuit between them. The Zener diode ZD is for noise prevention. In addition, external device connection terminal T ₁ And external device connection terminal T ₂ An emergency broadcast facility 24 is connected between the two. Emergency broadcast equipment 24 has resistance R _E1 And resistance R _E2 Are connected in series and the external device connection terminal T ₁ And external device connection terminal T ₂ And a resistor R _E1 Microphone switches SW are connected in parallel at both ends. The emergency broadcast equipment 24 has an external device connection terminal T ₁ Via the power supply voltage V _CC Is supplied.
Where the resistance R ₁ ~ R ₉ , R _E1 And R _E2 Here is a specific example of the value of. Power supply voltage V _CC Is 24V, the resistance R ₁ ~ R ₉ , R _E1 And R _E2 Are, for example, 1 kΩ, 47 Ω, 15 Ω, 150 kΩ, 20 kΩ, 100 kΩ, 2 kΩ, 100 kΩ, 100 kΩ, 2.4 kΩ, and 510 Ω, respectively.
[0024]
Next, the state detection process of the external device in the fire receiver having the above configuration will be described with reference to the flowchart shown in FIG. 3 and the conceptual diagram shown in FIG. First, the control unit 31 proceeds to the process of step SP1 shown in FIG. _C Is changed from the normal “H” level to the “L” level and supplied to the state detection circuit 37, and then the process proceeds to step SP2. Thereby, the transistor Q constituting the virtual short circuit 52 ₃ Is turned off. At this time, the external device connection terminal T ₁ Or external device connection terminal T ₂ Except for the case where at least one of the two signal lines connecting the ₄ + Resistance R ₅ ) >>>> (resistance R _E1 + Resistance R _E2 ) ", That is, the resistance R _E1 And resistance R _E2 Since the relation that the combined resistance value of _D Is almost equal to the power supply voltage V _CC It becomes. That is, the detection voltage V _D Is the external device connection terminal T ₁ , T ₂ The voltage is set to be input in a state where the voltage is almost short-circuited. This detection voltage V _D Is the resistance R ₄ And R ₅ And the divided voltage V _DD And the resistance R ₆ Through divided voltage V _DD1 Is input to the control unit 31. Thus, the resistance R _E1 And resistance R _E2 From the combined resistance value of ₄ And resistance R ₅ Is much larger and the resistance R _E1 And resistance R _E2 In this case, since a voltage drop hardly occurs, the same voltage as in the short-circuit state, that is, the “external device connection terminal T ₁ Voltage = external device connection terminal T ₂ Of the external device connection terminal T ₁ And external device connection terminal T ₂ And a short circuit can be created.
[0025]
In step SP2, the control unit 31 sets the divided voltage V _DD1 Is converted into digital divided voltage data by an internal AD converter, and the divided voltage data is stored as an A value in the internal memory or the working memory 33, and then the process proceeds to step SP3. In step SP3, the control unit 31 performs a virtual short circuit release process (release of the virtual short circuit state), that is, the control signal S _C Is changed from the “L” level to the “H” level and supplied to the state detection circuit 37, and then the process proceeds to step SP4. Thereby, the transistor Q constituting the virtual short circuit 52 ₃ Is turned on, the detection voltage V _D Is the current external device connection terminal T ₁ And external device connection terminal T ₂ And a voltage corresponding to the state between Therefore, this detection voltage V _D Is the resistance R ₄ And R ₅ And the divided voltage V _DD And the resistance R ₆ Through divided voltage V _DD1 Is input to the control unit 31. That is, the external device connection terminal T ₁ Or external device connection terminal T ₂ When at least one of the two signal lines connecting the emergency broadcast facility 24 and the emergency broadcast facility 24 is disconnected, the power supply voltage V _CC Based on the external device connection terminal T ₂ Is not input to the detection voltage V _D Becomes 0V.
When the microphone switch SW is in a normal state where it is not pressed, the detection voltage V _D Is the resistance R ₇ / (Resistance R _E1 + Resistance R _E2 + Resistance R ₇ ) × power supply voltage V _CC ". In this case, the detection voltage V _D Is the power supply voltage V _CC About 0.4 times as large as
Further, when the microphone switch SW is depressed and in an emergency broadcast state, the detection voltage V _D Is the resistance R ₇ / (Resistance R _E2 + Resistance R ₇ ) × power supply voltage V _CC ". In this case, the detection voltage V _D Is the power supply voltage V _CC About 0.8 times of.
[0026]
In step SP4, the control unit 31 sets the divided voltage V _DD1 Is converted into digital divided voltage data by an internal AD converter, and the divided voltage data is stored as a B value in the internal memory or the working memory 33, and then the process proceeds to step SP5. In step SP5, the control unit 31 reads the B value from the internal memory or the working memory 33, and determines whether the B value is 0. If the result of this determination is “YES”, the control section 31 proceeds to step SP6. In step SP6, the control unit 31 sets the external device connection terminal T ₁ Or external device connection terminal T ₂ It is determined that at least one of the two signal lines connecting the emergency broadcast facility 24 and the emergency broadcast facility 24 is in a disconnected state, and for example, the “abnormal light” and the “emergency broadcast light” configuring the display unit 39 are blinked, After the sound indicating that the sound is abnormal is sounded from the sound unit 38, a series of processing ends. It should be noted that even if the A value in step SP2 is 0, it can be determined that the above-described disconnection state has occurred.
[0027]
On the other hand, if the result of the determination in step SP5 is "NO", that is, if the B value is not 0, the control section 31 proceeds to step SP7. In step SP7, the control unit 31 reads the A value from the internal memory or the working memory 33, divides the B value by the A value, and stores the result as the C value in the internal memory or the working memory 33. Thereafter, the process proceeds to step SP8. In step SP8, the control unit 31 determines which value the C value is from “0.0” to “1.0”. When the C value ranges from “0.0” to “0.6”, the control unit 31 proceeds to step SP9. In step SP9, the control unit 31 determines that the vehicle is in the normal state, and ends a series of processes to continue the monitoring state. If the C value ranges from “0.6” to “0.9”, the control unit 31 proceeds to step SP10. In step SP10, the control unit 31 determines that the microphone switch SW is pressed and is in an emergency broadcast state, stops the ringing of the district bell 22, and turns on the "emergency broadcast light" constituting the display unit 39. After that, a series of processing ends. Further, when the C value takes a value from “0.9” to “1.0”, the control unit 31 proceeds to step SP11. In step SP11, the control unit 31 sets the external device connection terminal T ₁ And external device connection terminal T ₂ Is determined to be in a short circuit state, and the “abnormal light” and the “emergency broadcast light” constituting the display unit 39 are blinked, or the sound indicating abnormal is sounded from the sound unit 38. , A series of processing ends.
[0028]
External device connection terminal T ₁ And external device connection terminal T ₂ Is 0 [Ω] in the case of the short-circuit state, and (R R) in the case of the normal state. _E1 + R _E2 ) [Ω], R in case of emergency broadcast _E2 [Ω], and the case where the wire is disconnected is infinity (∞). Therefore, by utilizing the difference of the external impedance in each state, in the configuration of this example, the external device connection terminal T ₂ Is a virtual short-circuit state, and the divided voltage V obtained at that time is _DD1 Voltage data (A value) corresponding to the external device connection terminal T ₂ Voltage V obtained when virtual short-circuit state is released _DD1 As shown in FIG. 4, the above four states are detected based on the result (C value) obtained by dividing the divided voltage data (B value) corresponding to. Therefore, according to the configuration of this example, it is possible to meet the demand of the user who desires to detect the state of the emergency broadcast facility 24 more accurately.
[0029]
That is, as can be seen from FIG. 1, the emergency broadcast facility 24 includes the microphone switch SW and the resistor R _E1 And R _E2 , The voltage of the commercial power supply of 100 V fluctuates, the output voltage value of the battery decreases due to spontaneous discharge or aging, or the power supply voltage V supplied from the commercial power supply or the battery. _CC Even if the value fluctuates, when the ratio is calculated with the C value in the short-circuit state being 1.0, the resistance R ₁ ~ R ₉ , R _E1 And R _E2 Takes the above-mentioned specific example, the ratio of the C value in the short-circuit state, the emergency broadcast state, and the normal state is approximately expressed by the equation (1). Further, the disconnection state can be confirmed when the A value and the B value become 0V. Therefore, the above-described fluctuation of the power supply voltage and the output voltage value of the battery decrease, and the power supply voltage V _CC , The disconnection state, the short-circuit state, the emergency broadcast state and the normal state can be detected.
1.0: 0.8: 0.4 (1)
Then, ideally, the C values in the normal state, the emergency broadcast state, and the short-circuit state are “0.4”, “0.8”, and “1.0”, respectively, as shown in Expression (1). However, due to the time difference for detecting the A value and the B value in the process of calculating the C value, the power supply voltage V _CC Even if slight fluctuations occur in the values, the values shown in FIG.
[0030]
Note that the A value and the B value are on the same path, that is, the transistor Q ₁ And Q ₂ , Resistance R ₁ ~ R ₆ And capacitor C ₁ Therefore, even if there are variations in the values of these circuit elements, those variations are removed in the process of obtaining the C value by dividing the B value by the A value. Therefore, it is not necessary to use a high-precision component such as a comparator, and the state detection circuit 37 can be configured at low cost.
[0031]
As described above, this embodiment has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like that do not depart from the gist of the present invention. Is also included in the present invention.
For example, in the above embodiment, the transistor Q ₁ ~ Q ₃ Is constituted by an NPN-type bipolar transistor, but the present invention is not limited to this. ₁ ~ Q ₃ May be constituted by a PNP-type bipolar transistor, a field-effect transistor (FET), an N-channel MOS transistor, or a P-channel MOS transistor. In this case, it goes without saying that a circuit configuration such as a resistor differs depending on each transistor.
[0032]
Further, in the above-described embodiment, the microphone switch SW and the resistor R _E1 And R _E2 Although the example in which the emergency broadcast facility 24 constituted by the following is applied is shown, the present invention is not limited to this, and the external device may be a relay. ) May output any binary voltage signal other than the voltage signal indicating the disconnection state and the short-circuit state or the binary voltage signal after the binary current signal is subjected to the current-to-voltage conversion.
Further, in the above-described embodiment, an example is described in which the A value is first detected in the processing of steps SP1 and SP2, and then the B value is detected in the processing of steps SP3 and SP4. After the B value is detected, the A value may be detected.
[0033]
【The invention's effect】
As described above, the present invention has a virtual short circuit for setting a virtual short circuit between two terminals connected to an external device, and detects a state of the external device, and a virtual short circuit. A first voltage value is detected from the state detection circuit when the virtual short circuit is set, and a second voltage value is detected from the state detection circuit when the virtual short circuit is not set by the virtual short circuit. A control unit that determines a short-circuit state between the two terminals, a disconnection state between at least one of the terminals and the external device, an operation state of the external device, and a non-operation state of the external device based on the second voltage value. Have. Therefore, various states of the external device can be accurately detected with a simple and inexpensive configuration even when the power supply voltage fluctuates.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a configuration of a state detection circuit and a configuration of an emergency broadcast facility that constitute a fire receiver according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a fire alarm system to which the fire receiver is applied.
FIG. 3 is a flowchart for explaining a state detection process of an external device in the fire receiver.
FIG. 4 is a conceptual diagram for explaining a state detection process of an external device in the fire receiver.
FIG. 5 is a schematic circuit diagram showing a configuration of a conventional fire receiver, a district sound ringing stop device connected thereto, a district bell, and an emergency broadcast facility.
[Explanation of symbols]
21 fire receiver, 22 district bell, 23 fire detector, 24 emergency broadcast equipment, 31 control unit, 32 program memory, 33 work memory, 34 data memory, 35 ₁ ~ 35 _n District Bell Drive Circuit, 36 ₁ ~ 36 _n Fire detection circuit, 37 state detection circuit, 38 sound section, 39 display section, 40 operation section, 41 communication circuit, 42 handset, 51 current limiting circuit, 52 virtual short circuit, C ₁ Capacitor, R ₁ ~ R ₉ , R _E1 , R _E2 Resistance, Q ₁ ~ Q ₃ Transistor, SA surge absorber, S _C Control signal, SW microphone switch, T ₁ , T ₂ External device connection terminal, V _CC Power supply voltage, V _D Detection voltage, V _DD , V _DD1 Divided voltage, ZD Zener diode.

Claims (3)

A state detection circuit that has a virtual short circuit for setting a virtual short state between two terminals to which the external device is connected, and detects a state of the external device;
A first voltage value is detected from the state detection circuit when the virtual short circuit is set by the virtual short circuit, and a second voltage value is detected from the state detection circuit when the virtual short circuit is not set by the virtual short circuit. Detecting a voltage value and, based on the first and second voltage values, a short-circuit state between the two terminals, a disconnection state between at least one of the terminals and the external device, and an operation state of the external device And a control unit for determining a non-operational state of the external device. The external device includes a microphone switch, is an emergency broadcast facility for notifying of a fire by voice message and performing evacuation guidance, and outputs a first output voltage value when the microphone switch is pressed, The fire receiver according to claim 1, wherein the second output voltage value is output when the switch is not pressed. A program for detecting a state of an external device in a fire receiver for causing a computer to function as the control unit according to claim 1.

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