JPS60191390A - Self-fire alarm system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field 1 The present invention relates to a self-fire alarm system.

[Background Art] Conventionally, in this type of self-fire alarm system that uses both a general type sensor and an intelligence type sensor, monitoring time periods are set for the general type detector and intelligence type sensor, respectively, and the signal A self-fire alarm system in which the voltage of the line is differentiated for each time period, that is, the voltage is lowered during the monitoring time period of the intelligence type sensor, and the current consumption during data transmission of the intelligence type sensor is suppressed. However, it is desired to easily realize shorting and opening of the signal line and monitoring of the operation of a general type sensor connected to the signal line while reducing current consumption. By the way, in a system using a signal line with a terminating resistor connected at the end, if the load on the signal line becomes large due to the connection of an intelligence type sensor with a repeater for constant monitoring, the only way is to reduce the value of the terminating resistor. It was difficult to detect the opening. In other words, this method has the disadvantage that the current consumption on the signal line due to the terminating resistor increases all the time. Also, by applying pulsed high voltage to the signal line,
A method has also been proposed in which the value of the pulse current flowing through the signal line is detected by using a Zener diode connected to the terminal end, but this method has the drawbacks that the configuration for applying high voltage is complicated and the cost is high.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a self-fire alarm system that can monitor each signal line using a clock-like configuration and consume less current. The system is to provide.

[Disclosure 1 of the Invention The present invention will be described below with reference to Examples. Figure 1 shows a basic schematic diagram of the self-fire alarm system, with receiver 1
An intelligence type sensor 2 and a general type sensor 3 such as a general type smoke detector or a heat sensor are mixedly connected to the signal line 1 derived from the signal line 1 . The receiver 1 superimposes a transmission signal Vs consisting of a pulse code signal including an address signal individually assigned to each intelligence type sensor 2 on the line voltage (or current) of the signal line 1 and cyclically sends it out sequentially. Then, it judges the information sent as a return signal R8 from each called intelligence type sensor 2, and monitors the line voltage and line current level of the signal line 1. The controller performs various control operations such as receiving level signals in response to sensing operations from the sensor. Figures 2 (,) to (e) show the 7-ohm signal format, and Figure 2 (a) shows the normal voltage of the signal line 1 (for example, 2
4V) and the transmission signal ■s to the intelligence type sensor 2
The voltage (peak is 12V) when transmitting is shown, and the receiver 1 shows the transmission time period A of the transmission signal Vs and return signal R3, the monitoring time period C of the general type sensor 3, and the signal line 1. The line voltage in the transmission time period A is set to a lower voltage than the line voltages in other time periods B and C by time division into the line monitoring time period B. Figures (b) to (
d) is a time chart showing a state in which the transmission signal Vs is sequentially switched and transmitted to each signal line 1;
) is the transmission time period A of the transmission signal ■S of the first signal line 1
The figure (c) shows the transmission signal V of the second signal line 1.
(d) shows the transmission time period A of the largest signal line 1 in this system, and in each transmission time period A of each signal line 1, each signal line 1
A transmission signal Vs for sequential access is transmitted from the receiver 1 to correspond to all the intelligence type sensors 2 connected to the receiver 1, and a return signal R8 is transmitted from the intelligence type sensor 2. Then, when all the transmissions are completed, the transmission time period A of the next signal line 1 is switched and set, and all the connected intelligence type sensors 2 are sequentially accessed in the same way. When the access on all lines 1 is completed, the access returns to the first signal line 1. In this way, the transmission signal IS is time-division multiplexed and cyclically received! 1, and a return signal R8 is sent back from the sensor 2. Each intelligence type sensor 2 can have its own address set, and when the address signal included in the transmission signal Vs sent from the receiver 1 matches its own set address, it can take in the control data in the transmission signal Vs. During the return period provided at the rear of the transmission signal Vs, various information is sent to the return signal R consisting of a pulse code signal.
8 and is superimposed and sent back to the receiver 1. When the general type detector 3 detects a predetermined smoke concentration or temperature, it turns on and shorts the signal port i through an appropriate resistor to change the level of line current or line voltage, etc., and sends a level signal to the receiving ff1il. It is designed to transmit a detection signal. Incidentally, FIG. 2(e) shows the relationship between the transmission signal Vs and the return signal R3.

In normal operation, the receiver 1 sequentially switches the signal line 1 connected to each intelligence type sensor 2, switches the line voltage of each line 1, and superimposes and transmits the transmission signal Vs to sequentially call each intelligence type sensor. It takes in the sensed information from 2 and makes a judgment, and in the monitoring time period B of signal line 1, the signal line! by detecting the voltage or current level of the signal line ILy′) short circuit;
It detects the opening and also monitors the operation of the general sensor 3 during the monitoring time period C of the general sensor 3.

Next, examples of the present invention will be described. FIG. 3 shows a block diagram of a system according to an embodiment based on the above-mentioned basic schematic configuration, in which a terminator 4 is connected to the end of each signal line 1 provided with means for switching the termination impedance. On the other hand, the reception iso 1 is provided with changeover switches SW1 for sequentially switching each line 1 for the number of lines, and
A signal transmission/reception control circuit unit 5 connected to the line by switching the changeover switch SW1, and a comparator circuit unit 6 for monitoring the sensing operation of the general sensor 3 and short circuits and opens of the signal line 1. , further processes the return signal R8 extracted from the signal transmission/reception control circuit section 5 and the transmission signal Vs sent to the signal line 1 via the signal transmission/reception control circuit section 5, and the monitoring signal from the comparator circuit section 6. It is composed of a signal processing circuit section 7 that performs processing, and a power supply section (not shown) that applies voltage to each signal line 1, and the signal transmission/reception control circuit section 5 has a signal line! The transmission signal \ls is superimposed on the signal line 1, and the return signal R superimposed on the signal line 1 is
3, and a return signal current detection circuit 9 that demodulates the return signal R8 from the extracted current of the signal line 1. As shown in FIG. 4, the terminator 4 connects a series circuit of a Zener diode ZD1 and resistors R, , R2 between the terminal ends of the signal line 1, and connects these resistors R, , R2.
2 is connected to the base of the transistor Tro via a capacitor C8, and the transistor Tro is further connected to both ends of the signal line 1 via a termination impedance switching resistor R3. It is constructed by connecting a series circuit of Tro and a resistor R3 in parallel to a terminating resistor R6.

The comparator circuit section 6 is connected to the signal line 1 as shown in FIG.
voltage is divided by resistors R, , R6, and this divided voltage is applied to the non-inverting input terminal of the comparator 10, and furthermore, a series circuit of resistor R6 and transistor T7 is connected between the non-inverting input terminal and the ground line. Furthermore, the base of this transistor Tr is connected to the connection point between the non-common line of the signal port t%11 and the resistor R8 via a series circuit of a resistor R7 and a Zener diode ZD2, and the resistor R8 is Connect the other end to the ground line. The signal processing circuit section 7 of the receiver 1 is composed of a logic circuit using, for example, a CPU, and has the function of setting each time period A, B, and C, and inputting the monitoring signal of the comparator circuit section 6, and A monitoring discrimination function that determines whether it is a fire signal or a line abnormality according to the monitoring time period B and 8-C in which the signal is input, and the signal line 1 is sequentially switched according to the transmission of the transmission signal Vs. Line switching function and transmission signal Vs
A transmission signal creation function that forms a signal in a predetermined signal format, for example, a start signal, an address signal, a control signal, and a return standby signal in this order, and sends it to the signal transmission/reception control circuit section 5, and captures the return signal R8. It has a function to judge the information sensed by the intelligence type sensor 2, and in the event of a fire or track abnormality, it can display or issue an alarm, and it can also display the address, line number, etc. on the display (not shown). It is equipped with a control function that allows the display to be displayed using Therefore, the receiver 1 has a changeover switch SW1.
. . . are sequentially switched to cyclic. By this switching, the voltage applied to the signal line 1 connected to the signal transmission/reception control circuit section 5 becomes the voltage across the series circuit of resistors R4 and R5 connected between the starting ends of the signal line 1. In other words, the 24V voltage supplied from the power supply is connected to the Zener diode ZD.
The line voltage is divided by a series circuit of resistors R, , and R5, and the line voltage is a Zener diode ZD. The voltage is reduced by subtracting the voltage across the terminal, for example, 12V, which is half of 24V. On the other hand, during the time period when this voltage is reduced, that is, during the transmission time period A, the transmission signal Vs sent from the signal processing circuit section 7 to the coupling circuit 8 is superimposed on the signal line 1. Then, the intelligence type sensor 2 at a predetermined address connected to the signal line 1 called in the transmission time period A receives the signal line 1 via an appropriate impedance during the period corresponding to the return standby signal after the control signal. The sensed information is transmitted as a return signal R3 in a short-circuited current mode. The return signal R8 is demodulated via the coupling circuit 8 and the return signal current detection circuit 9 and then sent to the signal processing circuit section 7.
It is determined whether a fire is occurring or normal.

The dog transmits a signal Vs from the signal line I to the next signal line 1.
When the transmission time period A of the signal line 1 is suddenly switched by the changeover switch SW, the Zener diode ZD
A resistor R9 is connected in series with the series circuit of resistors R1 and R5 instead of the resistor R9, and as a result, the line voltage rises to about 24V. When the voltage rises and falls by about 24 cm, the Zener diode Z D + of the terminator 4 becomes conductive, and a base current flows to the base of the transistor Tro through the capacitor C6. Therefore, the transistor Tr,)
is turned on, and the resistor R3 is connected in parallel to the terminating resistor R8 to lower the terminating impedance. This period during which the terminal impedance is low is the period until the capacitor C8 is charged and the base current no longer flows; that is, this period is the line monitoring time @B. Figure 6 (a), (1)
) shows the relationship between the transmission time period A and the monitoring time period B of the signal line 1. Now, when the termination impedance decreases in this way, the line current increases during that period. This increase in line current causes the voltages across resistors R1 and R5 to generate a predetermined voltage. If the load resistance connected to the signal line 1 is set at a predetermined value or higher, the voltage becomes a voltage higher than the predetermined voltage. Therefore, if the reference voltage applied to the inverting input terminal of the comparator 10 of the comparator circuit section 6 is set to be lower than that, the comparator 11-comparator 10 will generate an H'' monitoring signal if the line is normal. 1 is short-circuited at an arbitrary position, the line current increases further and the voltage across the resistor R8 rises.When this voltage exceeds the Zener voltage of the Zener diode ZD2 and the Zener diode ZD2 becomes conductive, the transistor Tr1 turns on and lowers the comparison input of the comparator 10 below the reference voltage. Therefore, the comparator 10 turns on and its monitoring output becomes L''. Furthermore, when the signal line 1 is opened (broken) at any point, the terminal impedance is separated from the line, leaving only the load impedance. When only this load impedance exists, the line current decreases and the comparison input of the comparator 10 becomes lower than normal. If the maximum of this voltage drop is limited in advance and calculated from a certain load impedance and the reference voltage of the comparator 10 is set higher than this voltage, the comparator 10 will be turned on in the same way as in the case of the above-mentioned line short circuit.
The output thereof is assumed to be "L". Therefore, in the signal processing circuit section 7, if the monitoring signal of the comparator circuit section 6 is "H" in the monitoring time period B shown in FIG. 7(b), the line is normal; If it is L as shown in (a) of FIG. 7(c), it is determined that an abnormality has occurred, and an alarm or display is issued.

FIG. 7(a) shows a time chart of line voltage.

Next, when the transistor Tro of the terminator 4 is turned off and the monitoring time period C of the general type sensor 3 begins, only the terminating resistor R8 is connected as a terminating impedance. In this case, the terminating impedance increases, so the line current decreases, but by setting the value of the terminating resistor R8 so that the comparison input voltage of the comparator circuit section 6 does not fall below the reference voltage, the general type sensor 3 operates. Unless otherwise, the output of the comparator 10 of the comparator circuit section 6 becomes H''.

In other words, if the monitoring signal is "H", this indicates that the general sensor 3 is in a normal operating state, and if the monitoring signal is "H", the signal processing circuit section 7 determines that there is no fire outbreak. Now, in the general type detector 3, a series circuit of a resistor R1o, a Zener diode ZD3, and a sensor contact S is connected to the signal line 1. When the sensor contact S turns on at the same time as fire detection, a low resistance value resistor RIO is connected to the signal line 1. For example, if the Zener voltage is 1
The signal line 1 is short-circuited through the Zener diode ZD of 0.0 cm and any series circuit. Therefore, the voltage between the starting ends of the signal line 1 decreases, and the comparison input voltage of the comparator 10 of the comparator circuit section 6 becomes below the reference voltage. Therefore, the output 1j of the comparator 10 becomes "I-", and the signal processing circuit section 7 outputs the monitoring signal "L" as shown in (b) of Figure 7 (c) in the monitoring time period C of the general type sensor 3. ”, it is determined that a fire has occurred, and actions such as an alarm or display are performed. Here, in order to reduce current consumption, the voltage of the signal line 1 may be lowered to the same level as the transmission time period A as soon as the sensing operation is determined. Needless to say, when Cyrisk is used in place of the sensor contact S, the values of the Zener diode ZD3 and the resistor R5° are set so that the holding current can be maintained even if the line voltage decreases. FIG. 8 shows the other side of the general type sensor 3, and this forge type sensor 3 uses the voltage drop that occurs in the resistor Rl 1 when the sensor contact S is closed to generate a confirmation light LED consisting of a light emitting diode. It is designed to light up.

FIG. 9 shows a concrete example circuit of the comparator circuit section 6 of the receiver 1, the coupling circuit 8 of the signal transmission/reception control circuit section 5, and the return signal current detection circuit 9. The output of the comparator 10 of the provided comparator circuit section 6 is sent to the signal processing circuit section 7 via the corresponding photocoupler 11. In addition, line switching is performed by driving the photocoupler 12 with a scan signal from the signal processing circuit section 9, and driving the transistor T of the switching section 13.
r2. Tr3 is turned off and the transistor Tr is turned on to connect the signal line 1 to the double-speed receiving control circuit section 5 through the transistor Tr.

A photocoupler 12 is provided for each line and is sequentially driven by scan signals. Further, when the photocoupler 12 is off, the transistors Tr21 and Tr3 are turned on, and the non-common side line of the signal line 1 is grounded via the resistor R9 via the transistor Tr2. Thus, a circuit X consisting of a comparator circuit section 6 and a switching section 13 is provided for each line. A coupling circuit 8 of the signal transmission/reception control circuit section 5 includes a transistor Tr5 and a current detection resistor between the point where the outputs of the switching sections 13, which are provided corresponding to each signal line 1, are commonly connected and the ground. R12 and a Zener diode ZD0 with a Zener voltage of 12V are connected in series, and the data of the transmission signal Vs is sent from the signal processing circuit section 7 via the photocoupler 14 (then the transistor Tr
Transistor Tr5 is turned on and off in response to the data of the transmission signal Vs via s, and when it is on, the line voltage is set to 12V by the Zener diode ZD, and when it is off, the Zener voltage connected in parallel to transistor Tr5 is set to 5V. Zener diode ZD, and the Zener diode Z
The transmission signal Vs is superimposed on the line voltage by Do. On the other hand, the transmission signal R8 is a return standby signal for the transmission signal Vs, which is sent as the line current level when it is "H", and this current mode signal is converted to the voltage across the current detection resistor R12. It is then detected.

16- The voltage detected by the transmission signal current detection circuit is amplified by the amplifier 15, and the comparator 16 distinguishes it between noise and signal, and also shapes the waveform and outputs the return signal R.
8 is demodulated. This return signal R8 is then sent to the signal processing circuit section 9 via the photocoupler 17. In the figure, 18 is an amplifier for generating a reference voltage for the comparator 16.

The circuit configuration of the intelligence type sensor 2 is as shown in FIG. 10, for example, as a smoke sensor. In other words, the base 19a and the head 19b constitute a body part, and the head 19b includes an output circuit part 2 that outputs an analog signal according to the light reception level of the light receiving elements 21a and 21b.
3a and 23b, and light emission control sections 25a and 25b that control light emission of light emitting elements 24a and 24b. In the smoke detection section 2o, a light emitting element 24a and a light receiving element 21a are arranged facing each other, a light emitting element 24b and a light receiving element 21b are arranged facing each other, and the light from the light emitting element 24a is directly received by the light receiving element 21a, and the light from the light emitting element 24b is directly received by the light receiving element 21a. is directly received by the light receiving element 21b,
Further, the light receiving element 21b receives the scattered light emitted from the light emitting element 24a, and the light receiving element 21a receives the scattered light emitted from the light emitting element 24b.
The light-emitting element 24a] and the light-receiving element 211 constitute a first sensing system, and the light-emitting element 241] and the light-receiving element 21a constitute a second sensing system.In a normal alert state, both sensing systems do not operate. They are supposed to be done alternately. On the other hand, the base 19a removably mounts the head 191], supplies power to the circuits in the head 19b, and outputs circuit sections 23a, 231 . output and the light emission control section 25
a.

251), and there is an output circuit section 23 inside.
A signal conversion circuit section 26a that A/D converts the analog signals from a and 23b and outputs digital light reception level data.
, 26b, and the signal conversion circuit section 26a.

26I] as return information to the receiver 1, and creates a return signal Vs consisting of a pulse code signal based on the information, and the address setting unit 27
It takes in the address set in and the control data of the transmission signal Vs transmitted from the reception (!Iso 1) via the signal line l, controls each light emission control unit 25a + 25b, and sends back the transmission signal Vs following the transmission signal Vs. The above return signal V during the waiting period
Arithmetic signal processing circuit unit 2 that performs signal processing such as sending out s.
8 and the signal line 1 to extract the transmission signal \lS or to superimpose the return signal R8 on the signal line 1, and a power supply section 30 which obtains power through the coupling circuit section 29. At least it has one.

Although the above-mentioned comparator circuit section 6 is used for monitoring the signal line 1 and the general type sensor 3, separate comparator circuit sections may be provided. Further, the receiver 1 may be constructed from a repeater that relays signals to other systems. Furthermore, the signal line l may be monitored as follows. In other words, as shown in Figure 11 (a), (b), and (c), all line voltages are manually lowered to a low voltage level all at once, and then a monitoring time period B for signal line 1 is created for each. , the signal port #i1 may be monitored at any time. -Also, instead of the second receiver 1, a receiver 1 having a function as a repeater for other systems may be used.

19- [Effects of the Invention] The present invention provides a transmission time period for transmitting a transmission signal and a return signal, a monitoring time period for monitoring a signal line, and a monitoring time period for monitoring a general type sensor in the above-mentioned self-fire alarm system. and a signal line voltage switching means for setting the line applied voltage of the signal line in the transmission time period of the transmission signal to be lower than the line applied voltage in other time periods. , it is possible to reduce the current consumption of the intelligence type sensor when accessing, and it also detects the rise in line voltage when switching from the transmission time period to the next signal line monitoring time period and connects it to the end of the signal line. Since it is equipped with a terminating impedance switching means that increases the line current by setting the connected terminating impedance low during the monitoring time period of the signal line, the current consumption can be reduced compared to the case where the terminating impedance is always small. As a result, it is less affected by the load-in-bee die, has the effect of reliably detecting an open signal line, and has a simpler circuit configuration than when generating pulsed high voltage. This also has the effect of reducing costs.

[Brief explanation of the drawing]

Fig. 1 is a general circuit block diagram that is the basis of the present invention, Fig. 2 is a time chart for explaining the operation of the same as above, Fig. 3 is a circuit block diagram of an embodiment of the present invention, and Fig. 4 is a block diagram of the same as above. Circuit diagram of the terminator, Figure 5 is a circuit diagram of the comparator circuit section of the same as above, Figure 6-70 is an operation explanatory diagram of the terminator as above, $
Figure 7 is an explanatory diagram of the operation of the comparator circuit section, Figure 8 is a circuit diagram of the other side of the general type sensor same as above, Figure 9 is a specific circuit diagram of the main part of the receiver used in the above, and Figure 10 is the same as above. Figure 11 is a block diagram of the main parts of the intelligence-type smoke detector in use, and there is an explanatory diagram of the operation of another embodiment of the same as above, 1 is a receiver, 2 is an intelligence-type detector, 3 is a general type sensor, and 4 is a Terminator, 6 is a comparator circuit section, 10 is a comparator circuit section, A is a transmission time period, B is a signal line monitoring time period, C is a general type sensor monitoring time period, Vs is a transmission signal, 1 is a signal line It is.

Claims (1)

[Claims] 1) A general type sensor that short-circuits a signal line through an appropriate impedance during a sensing operation, and an address is assigned individually, and a transmission signal containing the address data is superimposed on the signal line and, when received, sends a return signal to the signal line. The above-mentioned transmission signal, which consists of an intelligence type sensor that superimposes and returns sensed information, and a pulse code signal containing address data individually assigned to each intelligence type sensor, is superimposed on the line voltage or line current on the signal line. Cyclic time-division multiplex transmission is performed sequentially, and the sensed information sent as a return signal from each called intelligence type sensor is judged, and the line voltage or line current level of the signal line is monitored. In a self-fire alarm system comprising a receiver that detects the sensing operation of a sensor and monitors the signal line based on the level of line current flowing through the signal line terminator, the transmission signal and the return signal are transmitted. Means for sequentially setting a transmission time period, a monitoring time period for monitoring a signal line, and a monitoring time period for monitoring a general type sensor in a time-sharing manner, and a line applied voltage of the signal line during the transmission time period of the transmission signal. a signal line voltage switching means that sets the voltage applied to the line to be lower than the line applied voltage in other time periods; 1. A self-fire alarm system comprising: a terminal impedance switching means connected to a terminal end of the signal line for increasing the line current by setting the terminal impedance low during a signal line monitoring time period.