JPH02247797A - Sensor - Google Patents

Abstract

PURPOSE:To shorten a testing time and to improve accuracy by preventing a short-circuit signal from being transmitted to a transmission line while closing an output circuit in a sensor at the time of testing its operation. CONSTITUTION:When a microprocessor (MPU) decides a test command signal at the time of executing a test, a switch element SW2 is opened, a drive command S3 is outputted to a testing drive circuit DR2 and a testing light emitting element LED2 is emitted. A fire abnormal signal S2 is outputted as a test result signal and applied to a switching circuit SW1 to connect the circuit SW1. Since a high resistor R1 is inserted in series at the time of the test, a short-circuit signal is not sent to the receiving side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a plurality of sensors that are connected to a P-type receiver and can be tested remotely.

[Prior art and problems] Multiple detectors are connected to a fire receiver via transmission lines,
When a sensor detects an abnormality, the switching circuit inside the sensor that detected the abnormality operates and sends a short circuit signal to the fire receiver, allowing the receiver to know that a fire has occurred. P-type fire alarm systems are known.

When performing an operation test of a fire detector in such a P-type fire alarm system, a tester is connected to the receiver side, and the tester is connected to a specific fire detector via a transmission line. , sends an operation test signal for operating the switching circuit, causes the specific sensor to send the above-mentioned short circuit signal to the transmission line, and on the testing device side, the short circuit signal is transmitted from the specific sensor. There is a method that determines the quality of test results by determining whether or not the test results have been tested.

In this method, each sensor under test performs the same operation as when a real fire occurs and sends out a short circuit signal to the transmission line, so even if the receiver receives the short circuit signal, In response to this, fire actions including a fire display will be performed.This is fine if it is desired to perform a fire display test on the receiver, but if not, the test will take a long time. In other words, in order to perform the next operation test on another sensor, first restore the receiver manually, check the drop in the sensor voltage across the transmission line during operation, and after the restoration operation, test the sensor again. This means that it is necessary to wait for a period of time, for example 7 to 8 seconds, until the device stabilizes.

Therefore, when testing the operation of a large number of sensors, the recovery operation is not only troublesome but also takes a long time.For example, if the test time is 210 seconds, 500 sensors are tested. The time is 10 (
(seconds) x 500 (pieces) = 5,000 (seconds), which means that the test will take a very long time.

[Means for Solving the Problems] Therefore, an object of the present invention is to improve the efficiency of the operation test when remotely conducting an operation test of a fire detector connected to a P-type receiver, and to improve the efficiency of the test. The object of the present invention is to improve reliability, and in particular, to provide a sensor that can test the operation of all the elements within the sensor in a relatively short period of time.

Therefore, according to the present invention, in a sensor including an output circuit that enters a closed state when an abnormality is detected to short-circuit the transmission line and send out an abnormal signal via the transmission line, A resistor inserted in series in the output circuit in response to a test command signal sent out by the
the resistor for preventing the transmission line from being short-circuited when the output circuit is closed; and the test resistor for returning a test result signal in response to the test command signal via the transmission line A sensor is provided, comprising: determination means for determining whether or not the output circuit is in a closed state based on an operation test conducted in response to a command signal.

[Function] A resistor is inserted in series in the output circuit in response to the test command signal sent via the transmission line, so during testing, the output is determined by the operation test performed in response to the test command signal. Even if the circuit is closed, the transmission line will not be short-circuited, thus preventing abnormal signals from being sent out via the transmission line.

The determining means determines whether or not the output circuit is in a closed state through an operation test conducted in response to the test command signal, and the result is sent back as a test result signal via the transmission line.

In this way, what is sent back via the transmission line is the test result signal rather than the short circuit signal as an abnormal signal, so the receiver is not activated and there is no need for recovery operations, thus reducing test time. .

Further, during the test, the output circuit is also tested by determining the closed state of the output circuit by the determination means, so that highly accurate tests can be performed on all elements within the sensor.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a block circuit diagram showing an internal circuit of a diffused light type smoke detector according to an embodiment of the present invention, taking the case of a smoke detector as an example. Of course, the present invention is not limited to smoke detectors, but can be applied to various detectors such as heat detectors and gas detectors.

In FIG. 1, the terminal T1 of the microprocessor MPU
and T2 are shown connected to a monitoring drive circuit DR that drives a monitoring light emitting element LED, and a testing drive circuit DR2 that drives a testing light emitting element LED. The microprocessor MPU outputs a light emission control signal for monitoring operation or test operation to each of these drive circuits. The output of an amplifier AMP for amplifying the output of the light receiving element PD is connected to the microprocessor MPU at a terminal T, and a fire determination circuit FDC for determining a fire based on the output from the amplifier AMP is connected at a terminal T4. It is connected. A synchronizing signal is output from terminal T of the microprocessor MPU to the fire judgment circuit FDC.

Note that the drive circuits DR, DRl, and the light emitting element L E
D + , LED2, light receiving element PD, amplifier AMP, and fire judgment circuit FDC constitute sensor section SE.

Further, a signal transmitting/receiving circuit SRC is connected between the transmission line C-L and the terminal T5 of the microprocessor MPU so as to transmit and receive signals to and from a receiver (not shown) via the transmission line C-L.
is connected. Power is also supplied from the receiver via the transmission line CL, and therefore a constant voltage circuit CvC is also shown connected to the transmission line CL.

Resistors R, , R, , R1, light emitting element LED for operation display, ,
An output circuit OTC consisting of an operating switching circuit SW7 and a test switching element SW2 that is closed during monitoring and opened during testing is connected to the transmission line so that it outputs a short circuit signal to the receiver when the sensor is operating. Connected between CL and L. The terminal T6 of the microprocessor MPU is connected to the switch element SW2 of the output circuit OTC, and outputs an open command to the switch element SW2 during testing, and the terminal T is connected to the output circuit OTC when the sensor is operated.
The output circuit OTC is connected to receive an operating signal, that is, a signal representing the closed state.

The operation of the sensor shown in FIG. 1 will be explained using the timing chart shown in FIG. 2.

First, to explain the operation during normal monitoring, the switch element SW2 in the output circuit OTC is closed by a command from the terminal T6 of the microprocessor MPU (SW2 on in FIG. 2), and is a light emitting element LED which outputs a light emitting control signal S1 to a terminal T and a monitoring drive circuit DR at predetermined time intervals INT, for example every 4 seconds, to cause the light emitting element LED to emit light. , and the light receiving element PD, when there is smoke between them, the light emitting element L E D
The arrangement is such that the light from + is reflected depending on the smoke density existing between the two and reaches the light receiving element PD. Therefore, if there is smoke between the two, the time will change as shown in Figure 2. When the monitoring light emitting element LED emits light at t1, the light receiving element PD receives reflected light according to the smoke density and outputs a light reception signal to the amplifier AMP.

The light receiving signal received by the light receiving element PD and amplified by the amplifier AMP is given to the terminal T of the microprocessor MPU, and is also given to the fire judgment circuit FCC, where a fire judgment is made and the smoke density is determined to be abnormal. If the terminal Tcc of the fire judgment circuit FDC is
At time t2 (Fig. 2), a signal S indicating a fire abnormality
2 is output.

The fire abnormality signal output from the terminal Tcc of the fire judgment circuit FDC is given to the switching circuit SW1 to make the switching circuit SW1 conductive, thereby causing the transmission line C-L connected from the receiver (not shown) to operate. A short circuit occurs through the display light emitting element LEDs, the resistors R2 and R1, and the switch element SW2, which is closed under normal monitoring conditions, and in this way, a fire abnormality occurs on the receiver side. A short circuit signal is sent to indicate that the

In this case, since the connection point of the resistors R2 and R1 in the output circuit OTC is connected to the terminal T of the microprocessor MPU, the microprocessor MPU can know that the output circuit OTC has operated at time t2. In FIG. 2, since the switch element SW2 is closed, the potential at the terminal Tγ is V when there is no fire abnormality.

, and the potential at terminal T when a fire abnormality occurs is shown to be V.

In this way, the microprocessor MPU receives the operating signal of the output circuit OTC at the terminal T, and the output of the amplifier AMP is also given to the terminal T of the microprocessor MPU, so that the microprocessor MPU When an operation signal is received at terminal T, the analog smoke density signal given from amplifier AMP to terminal T is added to terminal T, as necessary by adding a self-address.
It is also possible to send the information to the receiver side via the signal transmitting/receiving circuit SRC and across the transmission line CL.

When performing a test, a test command signal is first sent from a tester or the like on the receiver side (not shown), and is received at the terminal T of the microprocessor MPU via the signal transmitting/receiving circuit SRC.

When the microprocessor MPU receives the signal and determines that it is a test command signal, it first outputs an open command from the terminal T6 to the switch element SW2 at time t (Fig. 2), thereby causing the switch to open. Element SW2
is opened.Next, the microprocessor MPU outputs a drive command S to the test drive circuit DR from the terminal T2 at time t, causing the test light emitting element LED to emit light.

The test light emitting element LED is the test light emitting element LED2.
is arranged at a position such that the light receiving element PD receives a sufficient amount of light to generate a fire abnormality signal when the
Therefore, when the test light emitting element LED emits light according to the drive command S3, the light reception signal received by the light receiving element PD is
The signal is amplified by the amplifier AMP and applied to the terminal T of the microprocessor MPU and the fire judgment circuit FDC, and the terminal Tcc of the fire judgment circuit FDC outputs the fire abnormality signal s2 as a test result signal at time ts. , the fire abnormality signal, ie, the test result signal S2, is applied to the switching circuit SW1 of the output circuit OTC to make the switching circuit SW1 conductive.

During the test, the switch element SW2 is open, so a resistor R1 is further inserted in series with the output circuit OTC compared to during normal monitoring, and the resistor R is connected to the transmission line C-L.
Since the resistance is high enough to prevent shorting, no shorting signal is sent to the receiver.

However, since the switching circuit sw is made conductive, the potential at the connection point between the resistors R2 and R5 of the output circuit OTC is 12 at the time t, as shown in FIG.
The potential decreases with age, and the drop in potential is caused by the microprocessor MPU.
The operating output or closed state output of the output circuit OTC is applied to the terminal Tt of the output circuit OTC, thereby allowing the microprocessor MPU to know that the test result is normal. The microprocessor MPU sends a signal indicating that the test result is normal to the transmission line C-L via the signal transmitting/receiving circuit SRC as a test result signal with its own address attached.
This allows the tester to know that the sensor is operating normally.

If the operating output is not received at the terminal T6 within a predetermined period of time after the drive command is issued from the terminal T2, the microprocessor MPU sends the drive circuit DR, amplifier AM
It is assumed that some abnormality such as a failure has occurred in P, the fire judgment circuit FDC, the switching circuit SW1, etc., and a self-address is added to the test result signal indicating the test result abnormality, and the signal transmitting/receiving circuit SRC is sent from the terminal T. Transmission line C-
Send on top.

The constant settings of each element in the output circuit OTC so that a short circuit signal can be sent on the transmission line C-L only in the event of a fire and not during a test will be explained with reference to FIG. In addition to the output circuit OTC similar to that shown in Fig. 1, Fig. 3 also shows a relay RL (impedance r, moving current ■) in the receiver connected via the transmission line C-L. It is shown. The relay RL is connected to the output circuit O
It is operated by a short circuit signal from the TC, and the contact signal when the relay RL is operated allows the receiver side to know the occurrence of a fire abnormality.

In Fig. 3, the power supply voltage supplied between the transmission line C and L is E, the impedance of the relay RL is r, the sensing current is I, and the voltage drop at the operation display light emitting element LED3 is Vp. Suppose there is. Also, points P and 9 are input to terminal T of the microprocessor MPU in FIG.
The potential between them is expressed as V.

(1) Now find the voltage V between point P and 0.

■During normal fire monitoring, if the PQ potential v=v in the case of non-fire, then v6=+
E If the potential between P and Q at the time of fire outbreak V = V +, then V
= [R3/(R2+R3+ r)]X(E-Vp)+V
During the p■ test, if the PQ potential v=v2 when the test result is normal, then V2 = [R3/ (R1+ R2+ Rs+
r) koX(E-VP)+Vp If the potential between PQ in the case of an abnormal test result such as a failure V = v3, then Vko = E. These potentials v0 to V3 are shown in Fig. "Operation output" column.

(2) Next, the transistor or switching circuit S
Find the current flowing through relay RL of the receiver when Wl is conductive.

■If the current is 11 when a fire occurs during normal fire monitoring, it L:, (EVp)/(Rt + R30r)■If the current is 12 when the test result is normal during a test, it''- (E VP )/ (R++ Rz+ R
ff+r).Thus, in order to operate the relay RL only in the event of a fire and not to operate it during a test, resistors R,,R must be set so that the impressed current I of the relay RL satisfies it > I > i2. , , R1 etc. must be set.

Several advantages can be mentioned in the operation of the present invention described above.

First, according to the present invention, during an operation test, information can be sent and received with a tester connected to the receiver side, and
By connecting a resistor R in series to the output circuit OTC, the switching circuit operates but does not send a short circuit signal, that is, a fire signal, to the receiver, so there is no need to perform receiver recovery operations. This eliminates the waiting time associated with testing, allowing for efficient testing in a short period of time.

2 seconds, the time to test 500 sensors is 2 (seconds) x 500 (pieces) = 1,000 (seconds). Therefore, compared to the conventional example described above, the time required to test 500 sensors is 115 seconds. The test can now be performed.

Additionally, it may be desirable to also test the fire display operation on the receiver side. In such a case, for example, a test command signal that causes the switch element SW2 to remain closed is sent to the sensor to be tested, so that the sensor keeps the switch element SW2 closed even during the test.
2 remains closed, and a short circuit signal as a fire abnormality signal is sent onto the transmission line C-L. Since the short circuit signal activates the receiver, display operation tests are also possible. In this case, the correspondence between the activated detector and the fire display window of the receiver can be established by storing the line number in the testing device.

In addition, as a method to prevent the operational output of the output circuit OTC, that is, the short circuit signal, from being sent onto the transmission line C-L during the test, the output from the fire judgment circuit FDC is transferred to the switching circuit SW1.
It is conceivable to switch at the time of testing so that the signal is not applied directly to the terminal T of the microprocessor MPU, but rather to the terminal T of the microprocessor MPU. However, with this method, it is not possible to test the output circuit oTC itself including the switching circuit SW.In this respect, according to the above embodiment, the output circuit OTC is also activated by the fire abnormality signal generated during the test. Since the test drive circuit DR2, the amplifier AMP, the fire judgment circuit FDC, etc., the output circuit OTC can also be tested.

[Effects of the Invention] As described above, according to the present invention, the output circuit of the sensor is closed during the operation test, but the short-circuit signal is not sent to the transmission line, so all the elements in the sensor are compared. This has the effect of allowing tests to be performed with high accuracy in a short period of time.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing a sensor according to an embodiment of the present invention, FIG. 2 is a timing chart for explaining the operation of FIG. 1, and FIG. 3 is a diagram showing the values of elements in the output circuit. In Figure 0, which is a circuit diagram for explaining the setting method, OTC is an output circuit, R1 is a resistor, SW1 is a switching circuit, SE is a sensor section, and CL is a transmission line. Patent applicant: Nomi Disaster Prevention Industry Co., Ltd. - 1^P Funeral map

Claims (1)

[Scope of Claims] A sensor including an output circuit that becomes closed when an abnormality is detected and short-circuits the transmission line to send an abnormal signal through the transmission line, comprising: a resistor inserted in series in the output circuit in response to an incoming test command signal,
the resistor for preventing the transmission line from being short-circuited when the output circuit is closed; and the test resistor for returning a test result signal in response to the test command signal via the transmission line A sensor comprising: determination means for determining whether or not the output circuit is in a closed state based on an operation test performed in response to a command signal.