JPH0743797B2 - Analog type sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an analog type sensor used in a fire alarm device or the like.

[Prior Art] Conventionally, a plurality of fire detectors are installed in each warning area in a fire alarm device, and an analog signal detected from the fire detectors is sent to a central monitoring device by using a transmission means, and the central monitoring device side There are some that judge whether there is a fire or not from the analog data detected from each sensor. Also, since many fire detectors are installed, they are designed to reduce power consumption as much as possible. For this reason, fire detectors that consume a large amount of current, such as photoelectric smoke detectors and semiconductor heat detectors, operate intermittently (once every few seconds) to reduce the current consumption. In the sensor which cyclically calls from the monitoring device and returns analog data, the detection unit is made operable in synchronization with the calling. Also, when controlling from a central monitoring device of multiple disaster prevention devices (fire doors, smoke evacuating devices, etc.) installed in each area in conjunction with the alarm operation, central monitoring due to transmission related failures It has been proposed that when a command from the device cannot be issued, the disaster prevention device (control terminal) is directly controlled by a control signal judged by each fire detector. For example, Japanese Patent Application Laid-Open No. 60-164802, "Disaster Prevention Monitoring and Control Device".

[Problems to be Solved by the Invention] Since such an analog type sensor does not make any judgment by itself, it cannot have a judgment function unless it is combined with a central monitoring device. Therefore, once a failure occurs in the transmission system, the monitoring function of the sensor that is monitoring in synchronization with the polling call from the central monitoring device is impaired,
Further, there is a drawback that the disaster prevention device cannot be controlled by the control command from the central monitoring device.

[Means for Solving the Problems] The analog type sensor of the present invention has the temperature, smoke density,
In an analog type sensor that sends back a data signal indicating the detected analog amount such as gas concentration, when the calling address from the central monitoring device is received and an address matching pulse is matched with the unique address set for itself, an address matching pulse is sent. An address detector for outputting, a pulse signal based on the address coincidence pulse from the address detector, and a pulse oscillator circuit for outputting a pulse signal based on the oscillation operation when the address coincidence pulse does not arrive for a predetermined time or more; A pulse signal generated by the oscillating operation that does not output the address matching pulse and a detection unit that enters the detection operation state based on the pulse signal from the pulse oscillating circuit and outputs a detection analog signal of temperature, smoke concentration, gas concentration, etc. The output analog level of the detection unit in the detection operation state is determined based on A determination circuit, is characterized in that and an output means for outputting a control signal for driving the emergency equipment on the basis of the output of 該判 respective circuit.

[Operation] Even if a transmission failure occurs in the analog type sensor that performs the monitoring operation in synchronization with the polling call from the central monitoring device, the detection operation of the sensor can be maintained to make an abnormal judgment, and at this time, the sensor itself The control terminal device can be controlled by the control signal determined and output in step (1).

[Embodiment] An embodiment of an analog sensor of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an alarm device using the analog type sensor of the present invention. This alarm device monitors a fire, a gas leak, and the like, displays an alarm when an abnormality occurs, and controls a disaster prevention device. A central monitoring device 1 is connected to a plurality of transmission lines 4 extending from the central monitoring device 1. And an analog type sensor 2 and a control terminal 3 which normally drives a disaster prevention device (fire door, smoke proof device, etc.) based on a control signal from the central monitoring device 1 via the sensor 2. ing. The operation of the alarm device constructed as described above will be described. Normally, the central monitoring device 1 sequentially and cyclically calls each sensor 2 to request return data. The transmission unit of the sensor 2 receives the calling signal from the central monitoring apparatus 1 and outputs an address matching pulse when the signal matches the unique address set in itself. When this address coincidence pulse is output, power is supplied to the detection unit that detects the temperature, smoke concentration, gas concentration, etc. to activate the detection unit, and a signal indicating the detected analog amount is supplied to the transmission unit. The transmitter of the sensor 2 returns this signal as return data. Since the detection unit of the sensor 2 operates only at the time of calling, power saving can be achieved especially when the detection unit consumes a large amount of power. The central monitoring device 1 judges from this returned data whether or not an abnormality such as a fire or gas leak has occurred, and when the abnormality occurs, the occurrence status and location are displayed, and a buzzer or the like is sounded to give an alarm display. .
When it is determined that the disaster prevention device needs to be controlled, a control command is issued to the corresponding sensor 2. The sensor 2 receiving the control command outputs a control signal to the control terminal device 3. The control terminal device 3 that has received the control signal activates the disaster prevention device. When a failure occurs in the transmission system, the address matching pulse is not output from the transmission unit of the sensor 2. At this time, when the address coincidence pulse does not arrive for a predetermined time or more, a pulse oscillator that starts oscillating keeps the operation of the detection unit monitored and outputs a control signal when the detection level of the detection unit is a predetermined value or more to drive the control terminal unit 3. Then you can start the disaster prevention equipment.

Next, a specific embodiment of the analog type sensor of the present invention will be described based on the circuit block diagram shown in FIG.

This analog type sensor is a scattered light type smoke sensor, which is a transmission circuit 20 for transmitting and receiving signals to and from the central monitoring unit 1, and an A / D converter 21 for converting a detected analog signal into a digital signal.
And a command identifier 22 for identifying a control signal from the transmission circuit 20 and an address detector that outputs an address coincidence signal when the received address signal from the transmission circuit 20 is compared with a set unique address. 23, a low voltage circuit 24 for supplying power to each circuit, and transistors Q1, Q2,
A pulse oscillator circuit consisting of resistors R3 to R8 and a capacitor C2 that outputs an address match pulse with priority, and outputs a pulse at a specified cycle when the address match pulse does not arrive for a specified time or longer, and a capacitor C1, a resistor R2, and a knot circuit. An NT, a light-emitting diode LD, a photodiode PD, and an operational amplifier A1, which are intermittently supplied with power by the output of a pulse oscillation circuit, a detector for detecting smoke by scattered light, and a resistor R1,
From the OR circuit OR and thyristor SR, which consists of a diode D1 and a comparator CP, a discrimination circuit that detects that the output of the detection unit exceeds a predetermined level and outputs a control signal when the address match pulse has not arrived It is composed of an output circuit for outputting a control signal to the control terminal 3.

The operation of the sensor configured in this way is explained as follows:
The converter 21, the command discriminator 22, and the address detector 23 are in operation because power is supplied from the constant voltage circuit 24. The transmission circuit 20 receives a polling (calling) signal from the central monitoring apparatus 1 via a signal line. This call signal is composed of an address part and a command part. When the transmission circuit 20 receives this calling signal, it performs serial-parallel conversion and outputs the address portion to the address detector 23.
The address detector 23 compares the received address from the transmission circuit 20 with a preset unique address and outputs an address match pulse when they match. The command discriminator 22 discriminates the command portion from the transmission circuit 20 when an address coincidence pulse is output, and outputs a control signal according to the type of command. If the command is a return data request
A signal is output to the A / D converter 21, and a control signal is output to the OR circuit OR when the command is disaster prevention device control. On the other hand, the address match pulse (low level pulse) from the address detector 23 turns on the transistor Q1 via the resistor R8. The power supply voltage (Vc
c) Light emitting diode LD, knot circuit NT, operational amplifier A1
Etc. are supplied to the detection unit. The input of the knot circuit NT becomes high level for the time due to the time constant of the capacitor C1 and the resistor R2, while the output becomes low level during that time and the light emitting diode LD
An electric current is passed through and pulsed light is emitted. The light beam emitted from the light emitting diode LD is applied to the dark box at a position where it does not directly enter the photodiode PD. Outside air can freely flow into this dark box, and when smoke at the time of fire occurrence enters, the photodiode PD of the scattered light due to this smoke detects the smoke. The detection signal of the photodiode PD is amplified by the operational amplifier A1 and input to the A / D converter 21. The A / D converter 21 performs analog-to-digital conversion of the detection signal and supplies it to the transmission circuit 20, and the transmission circuit 20 parallel-serial converts it as return data and outputs it to the signal line. Operational amplifier A1
The detection signal from is applied to the comparator CP via the resistor R1, but at this time, the output of the comparator CP is also at the low level because it is forcibly brought to the low level by the address match pulse. The charge stored in the capacitor C2 when the transistor Q1 is on is then discharged through the resistors R3, R4, and R5, but since the time constant is set longer than the polling period, the discharge of the capacitor C2 ends. The next address match pulse causes the battery to be charged again. However, when a failure occurs in the transmission system and polling is stopped and the address match pulse does not arrive, the discharge of capacitor C2 ends and current is supplied to the base of transistor Q2 via resistor R5 and the current flows to the collector. start. The collector current of the transistor Q2 causes a current to flow to the base of the transistor Q1. A current flows through the collector of the transistor Q1 and the voltage drop across the resistor R3 starts charging the capacitor C2 via the resistor R4.
Q2 is turned on (saturated) and transistor Q1 is also turned on. When the capacitor C2 has been charged, the base current of the transistor Q2 is only that through the resistor R5.
Therefore, when the collector currents of the transistors Q2 and Q1 decrease and the voltage drop of the resistor R3 decreases, the base voltage of the transistor Q2 decreases and the transistor Q2 is turned off.
Q1 also goes off. Then, this operation is repeated and the pulse oscillation operation is performed. The resistance values of the resistors R3, R4, R5 are set so that R5 >> R3, R4. The time when the transistor Q1 turns on is mainly determined by the time constant R4 ・ C2,
The time to turn off is mainly determined by the time constant R5 ・ C2. The oscillation cycle is set longer than the polling cycle.
That is, the pulse oscillating circuit starts the oscillating operation when there is no call by polling. The pulse oscillation operation intermittently supplies power to the detection unit to maintain the detection operation.However, since the address match pulse is not output from the address detector 23 and is at a high level, the output of the operational amplifier A1 is the resistor R1. The specified comparison voltage Re
Compared with f. When the output of the operational amplifier A1 becomes higher than the comparison voltage Ref, the output of the comparator CP becomes high level and the OR circuit
Trigger thyristor SR via OR. The thyristor SR becomes conductive and outputs a control signal to the control terminal 3 through the terminal CT. When the transmission system is operating normally, the signal from the command discriminator 22 triggers the thyristor SR to output a control signal.

The means for returning the return data is not limited to this, and, for example, a pulse width modulator or a pulse amplitude modulator may be used instead of the digital signal using the AD converter.

[Effect of the Invention] As described above, the analog type sensor of the present invention is an analog type sensor in which the detection unit is set to the operating state only when the central monitoring device calls and the detection data at that time is returned to the central monitoring device. In the sensor, when there is no periodic call from the central monitoring device, the pulse oscillating circuit is activated to intermittently activate the detection unit, and when the level of the detection unit is above a predetermined level, a control signal is output and disaster prevention equipment Therefore, it is possible to perform local interlocking control when the system is down and provide a sensor with low power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an alarm device using the analog type sensor of the present invention, and FIG. 2 is a circuit block diagram showing an example of the analog type sensor of the present invention. 1 ... Central monitoring device, 2 ... Sensor, 3 ... Control terminal device, 4 ... Transmission line, 20 ... Transmission circuit, 21 ... A / D converter, 22 ... Command identifier, 23 ... … Address detector, 24
...... Constant voltage circuit, R1 to R8 ...... Resistance, Q1, Q2 ...... Transistor, C1, C2 ...... Capacitor, D1 ...... Diode, A1 ...
... operational amplifier, CP ... comparator, NT ... knot circuit, OR ...
… Or circuit, PD …… photodiode, LD …… light emitting diode, SR …… thyristor.

Claims (1)

[Claims] 1. An analog sensor, which is configured to return a data signal indicating a detected analog amount such as temperature, smoke concentration, gas concentration, etc. when calling from a central monitoring device, and receives a calling address from the central monitoring device. Then, an address detector that outputs an address match pulse when it matches the unique address set to itself and a pulse signal based on the address match pulse from the address detector are output, and the address match pulse arrives for a predetermined time or longer. If not, a pulse oscillating circuit that outputs a pulse signal based on an oscillating operation, and a detection unit that enters a detection operating state based on the pulse signal from the pulse oscillating circuit and outputs a detection analog signal such as temperature, smoke concentration, gas concentration, etc. When the address match pulse is not output, the detection operation state is set based on the pulse signal generated by the oscillation operation. It is characterized by further comprising: a discriminating circuit for discriminating a case where the output analog level of the detection unit is equal to or higher than a predetermined level, and an output circuit for outputting a control signal for driving a disaster prevention device based on the output of the discriminating circuit. An analog type sensor.