JP2775063B2 - Fire monitoring method and system using multiplex transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fire monitoring method using multiplex transmission control and a fire monitoring system using this method.

[Related Art] In recent years, when a fire has occurred due to a rise in the height of buildings, etc., a fire monitoring system for immediately detecting the occurrence of the fire and outputting an alarm and promptly guiding evacuation has been developed. Installation is mandatory, and various systems have been developed.

FIG. 10 shows an example of a reference configuration of such a fire monitoring system, in which a plurality of repeaters 200 and a fire receiver 100 in which a plurality of sensors SA having different addresses are connected to a sensor line l3. Between the multiplex signal line l1 and the sensor power line l2
And is connected.

In such a system, the control means 1 of the fire receiver 100
From 02, the multiplex signal with the address of the repeater 200 is transmitted to the multiplex signal line l1 through the multiplex transmission control unit 101, and the repeater 200
On the side, when the multiplexed signal with the address set by the address setting unit 201 is transmitted to the multiplexing transmission control unit 202, another multiplexing transmission control unit 203 is operated by the control means 204 to connect to the sensor line l3. Each sensor by transmitting multiple signals
After polling the SA and receiving the fire information from each sensor SA, the control means 204 performs necessary signal processing, and then again through the multiplex transmission control unit 202, through the multiplex signal line l1, Reply to the 100 side to monitor the sensor alert.

Then, in the system having such a configuration, when the alarm is issued from the sensor SA, the repeater 200 repeatedly checks the alarm from the sensor SA for a predetermined time, and then checks the fire receiver 100.
By outputting an alarm signal to the fire receiver 100, the burden of signal processing on the control means 102 on the fire receiver 100 side is reduced. However, in such a system configuration, the Since the need for the repeater 200 increases the cost, improvement has been desired.

[Problems to be Solved by the Invention] The present invention has been developed in view of the above circumstances, and a fire monitoring method using a highly reliable multiplex transmission method that simplifies the function of a repeater and this method. It is intended to provide a fire monitoring system for implementing the above.

According to a first aspect of the present invention, a monitoring signal based on a multiplex signal transmitted from a fire receiver is converted into a level corresponding to a sensor line by a repeater, and is sent to the sensor line as it is, and a reply signal from the sensor is transmitted. Is returned to the original multiplex signal level by the repeater and returned to the fire receiver side, the function of each repeater is reduced to signal level conversion and relay transmission,
By concentrating signal processing functions on fire receivers,
It is an object of the present invention to provide a fire monitoring method that can easily design a system and reduce costs.

A second invention simultaneously proposed is a fire monitoring system using the fire monitoring method of the first invention.
It is an object of the present invention to provide a fire monitoring system in which the system design is easy and the cost can be reduced.

[Means for Solving the Problems] The method of the present invention proposed in claim 1 proposed to achieve the above object is to provide a multiplex signal line by a polling method from the fire receiver side to the repeater side. A transmission switching signal of a specific multiplex transmission level specifying the repeater address is transmitted via the relay, and the relay receiving the switching signal transmits
Subsequent to this switching signal, the monitor signal designated by the detector address transmitted at a specific multiplex transmission level from the fire receiver via the multiplex signal line is converted into a level corresponding to the detector line. The relay signal is sent out to the detector line as it is, and the return signal returned from the detector receiving the monitoring signal to the detector line is converted again into the characteristic multiplex transmission level by the repeater side and returned to the fire receiver side. Finally, on the fire receiver side, by decoding the return signal returned through the multiplex signal line in this manner, the fire of the detector connected to the sensor line of each repeater is performed. Information can be detected for each sensor.

In order to achieve a similar object, the present invention proposed in claim 2 is a fire monitoring method according to claim 1, wherein the multiplexed signal is transmitted from the fire receiver side to the repeater side by a polling method. Transmitting a monitoring signal of a specific multiplex transmission level specifying a repeater address via a line,
On the side of the repeater receiving this monitoring signal, after judging the alert of the sensor based on the fluctuation of the voltage level occurring in the sensor line derived from each of them, the repeater converts it again to the return signal of the specific multiplex transmission level. The fire receiver side, and finally, the fire receiver side decodes the return signal returned via the multiplex signal line in this manner,
The present invention is characterized in that it is possible to detect the alarms of the sensors connected to the sensor lines of the respective repeaters and having no address set, even in units of the sensor lines.

The invention proposed in claim 3 relates to a fire monitoring system for implementing the above-mentioned method of the present invention, wherein a fire receiver is connected to each repeater in the system via a multiplex signal line. In order to monitor the repeaters and the sensors connected to the sensor lines of each of the repeaters, a transmission switching signal of a specific multiplex transmission level designating the repeater address and a specific switch setting of the sensor address are provided. A multiplex transmission control unit for transmitting a multiplex transmission level monitoring signal to the multiplex signal line by a polling method and receiving a return signal of a specific multiplex transmission level returned from the repeater and the sensor; According to the set control program, while operating the multiplex transmission control unit,
When the multiplex transmission control unit decodes the multiplex signal including the return signal received and performs necessary processing, the control means and, when the control means determines that the sensor has issued a fire, a fire detection sent out from the control means. Fire alarm means for receiving a signal and generating an alarm signal, and a sensor connected to each of the repeaters in the system via a sensor power supply line to supply power at a level required for the alarm operation of the sensor A power supply, and one of the repeaters has an address setting unit for setting an address required for transmission of a multiplex signal, and a relay connected to the multiplex signal line and transmitted to and from the fire receiver. A multiplex transmission control unit for receiving a transmission switching signal of a multiplex transmission level and a monitor signal designated with a sensor address, and sending out a return signal of a specific multiplex transmission level; Feeling A detector line for supplying power to the detector line, and a detector which is activated when the multiplex signal control unit receives a transmission switching signal, and which is transmitted from the fire receiver side following the switching signal. The monitor signal whose address is specified is converted into a level corresponding to the sensor line and transmitted to the sensor line, and a return signal from the sensor connected to the sensor line is received, and the multiplex signal control unit is received. The multiplex transmission control unit is operated in accordance with a level conversion control unit to be transmitted to the multiplex transmission control unit and a multiplex signal including a monitor signal received by the multiplex transmission control unit is decoded to perform necessary processing. A control unit for operating the level conversion control unit, a control unit including the multiplex transmission control unit and the control unit, and a signal conversion between the level conversion control unit. To enable the receiving,
In addition, an insulating transmission circuit for separating the power supply between them is provided.

Further, the monitoring system of the present invention proposed in claim 4 further embodies a level conversion control unit provided on the repeater side, wherein the level conversion control unit is configured so that the multiplex transmission control unit detects a fire reception. A switching circuit for shutting off a sensor power supplied to the sensor line by a sensor power cutoff signal sent from the control means when a transmission switching signal of a specific multiplex transmission level sent from the device is received. A switching circuit that operates with a predetermined time delay after the power supply of the sensor is cut off by the switching circuit, and the designation of the sensor address transmitted from the multiplex transmission control unit via the insulated transmission circuit is specified. The monitoring signal is converted to a level corresponding to the sensor line,
A level conversion circuit that sends the signal to the sensor line as it is, and a current that flows through the sensor line after the monitoring signal specified by the sensor address is transmitted by the level conversion circuit to the sensor line where the sensor power is cut off. And a current / voltage conversion circuit for converting the level change into a voltage signal and sending the voltage signal to the multiplex transmission control unit via the insulated transmission circuit.

Further, the fire monitoring system proposed in claim 5 relates to a fire monitoring system for implementing the method of the present invention proposed in claim 2, wherein the repeater transmits a specific signal from the fire receiver by a polling method. It is characterized in that it further comprises a level discriminating circuit for discriminating a voltage level occurring in the sensor line when receiving a multiplex transmission level monitoring signal.

[Operation] According to the method of the present invention, the fire receiver and the repeater usually send and receive a monitor signal and a return signal of a specific multiplex transmission level by a polling method to disconnect the sensor line. An abnormality such as a short circuit or a short circuit is monitored, and the alarm monitoring of the sensor connected to the sensor line is performed by transmitting a transmission switching signal from the fire receiver side to the repeater side. Upon receiving the transmission switching signal, the repeater activates the level conversion control unit to transmit a sensor monitoring signal subsequently transmitted at a specific multiplex transmission level from the fire receiver according to the sensor line. Level and sends it out to the sensor line.The return signal returned from the sensor line is converted to a specific multiplex transmission level by the level conversion control unit and sent back to the fire receiver. A reply signal returned in response to the monitoring signal is decoded, and the alert of the sensor is detected for each sensor.

According to the second aspect of the present invention, for a sensor to which an address is set, the alert of the sensor is detected in the above-described procedure. It can also detect alarms from sensors connected to the device line.

In this case, the repeater receiving the monitoring signal from the fire receiver determines the alert of the detector based on the fluctuation of the voltage level occurring in the detector line, and this determination signal is converted to a specific multiplex transmission level. Then, the signal is transmitted to the fire receiver side, and the fire receiver which decodes this signal detects the alarm of the sensor.
According to the present invention, the alert of the sensor can be detected on a sensor line basis, that is, only the sensor line that issued the alert can be detected, but when a general sensor is connected to the sensor line mixed with the sensor whose address is set. Can also monitor alerts.

In the fire monitoring system according to claims 3 and 4, the fire monitoring method of the present invention proposed in claim 1 can be implemented.

According to the fire monitoring system of the present invention described in claim 5, the fire monitoring method of the present invention proposed in claim 2 can be implemented.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, the fire monitoring system of the present invention will be described. In the figure, reference numeral 1 denotes a fire receiver, 2 denotes a repeater, and these are connected by a multiplex signal line l1 and a sensor power supply circuit l2. ing. In addition, a sensor line l3 which is supplied with power from the sensor power line l2 and is derived from each repeater 2 is provided.
Is connected to a sensor SA having an address and transmitting and receiving fire information by a multiplex signal.

The fire receiver 1 is connected to a multiplex signal line l1 to perform multiplex signal transmission and reception, a multiplex transmission control unit 11, a control means for performing multiplex signal processing according to a program stored in a memory 15 and outputting a control signal. 12, control means 12
Fire alarm means 13 for receiving a fire detection signal from the controller and issuing a fire alarm, a sensor power supply 14 connected to the sensor power supply line l2 for supplying power to the sensor SA, and a control signal from the control means 12 to an external correct / error terminal. An I / O port 16 for transmitting to a device (not shown) is provided. The other repeater 2 includes an address setting unit 21 for setting an address required for transmitting a multiplex signal, and a multiplex signal line l1.
A multiplex transmission control unit 22 that is connected to the fire receiver 1 and transmits and receives multiplex signals to and from the fire receiver 1; a level conversion control unit 23 that performs level conversion of multiplex signals between the fire receiver 1 and the sensor SA; The control means 24 performs necessary signal processing according to the control program and outputs a control signal. The control section 24 including the multiplex transmission control section 22 and the control means 24 and the level conversion control section 23 And an insulated transmission circuit 25 for insulated signal transmission.

In the fire monitoring system having such a configuration, the control unit 12 of the fire receiver 1 sends a multiplexed signal with the address of the repeater 2 to the multiplexed signal 11 through the multiplex transmission control unit 11 in accordance with a program to perform polling. On the device 2 side, if the address given to the transmission switching signal by the multiplex signal transmitted via the multiplex signal line l1 matches the address set by the address setting section 21, the control means 24 causes the insulated transmission circuit 25 to operate. Drive the level conversion control unit 23 through, after that, the multiplexed signal with the sensor address input to the multiplex transmission control unit 22 is transmitted to the level conversion control unit 23 via the insulated transmission circuit 25, The signal is converted into a level multiplexed signal suitable for the sensor SA and output to the sensor line 13. Then, the return signal from the sensor SA is returned to the level conversion circuit 23 via the sensor line l3 and converted into the level of the multiplex signal suitable for the fire receiver 1, and then the multiplex transmission control is performed through the insulated transmission circuit 25. The return signal of the sensor SA is transmitted from the multiplex transmission control unit 22 to the fire receiver 1 via the multiplex signal line l1. Therefore, when one repeater 2 is polled, a signal is directly transmitted / received between each detector SA connected to the detector line 13 and the fire receiver 1 via the level conversion circuit 23, and control is performed. No signal processing in the means 24 is performed. When the transmission and reception of the multiplexed signal with all the sensors SA connected to the sensor line l3 are completed, the fire receiver 1 sends out a transmission switching signal to terminate the transmission of the multiplexed signal with the repeater 2. Then, the process proceeds to communication with the next repeater 2.

Therefore, in the system of the present invention, since the polling is sequentially performed from the fire receiver 1 to each of the repeaters 2, the detectors having the same address set between the sensor lines 13 of the respective repeaters 2 are set. Even when there is, the fire receiver 1 can manage by assigning the address of the repeater 2 so that it can be identified, and the cost can be reduced by reducing the functions of the repeater 2. Become.

FIG. 2 is a block diagram showing the configuration of the repeater. In the figure, terminals NA and NB are connected to a multiplex signal line l1, and a multiplex signal from the fire receiver 1 is transmitted to a multiplex transmission control unit 22. And the multiplex signal from the multiplex transmission control unit 22 is returned to the fire receiver 1. The terminals F and FG are connected to the detector power line l2, and the sensing signals derived from the terminals LN and CN are output. In addition to supplying DC power to the device line 13, the DC power is also supplied to the level conversion control unit 23.

This level conversion control unit 23, when the multiplex transmission control unit 22 receives a transmission switching signal of a specific multiplex transmission level transmitted from the fire receiver, by a sensor power cutoff signal transmitted by the control unit 24, A switching circuit 23a for shutting off the sensor power supplied to the sensor line l3, and a switching circuit that operates with a predetermined time delay after the sensor power is shut off by the switching circuit 23a.
231a, and converts the specified monitoring signal of the sensor address transmitted via the insulated transmission circuit 25 following the transmission switching signal from the multiplex transmission control unit 22 to a level corresponding to the sensor line l3. The level conversion circuit 231b sends the signal to the sensor line l3 as it is, and the level conversion circuit 231b sends the monitoring signal specified by the sensor address to the sensor line whose sensor power is cut off. A current / voltage conversion circuit 23c that converts the fluctuation of the current level flowing through l3 into a voltage signal and sends it to the multiplex transmission control unit 22 via the insulated transmission circuit 25 is provided.

FIG. 3 shows the relationship between the transmission switching signal and the monitor signal designated by the sensor address sent to the sensor line 13 by the level conversion control unit 23.

FIG. 4 is a block diagram of a repeater having a function of adding a level discriminating circuit 27 and issuing a notification of a general sensor to which an address is not set, which will be described later, and detecting a disconnection of the sensor line. FIG. 5 is a block diagram of a repeater having a function of detecting a short circuit of a sensor line and detecting short circuit protection by adding a short circuit detecting / holding circuit 28 to the level determining circuit 27. .

Next, FIG. 6 shows a detailed circuit example of the level conversion control section 23, the level determination circuit 27, and the short-circuit detection / hold circuit 28 of the repeater 2 described above.

In the figure, terminals F and FG are connected to the detector power line l2,
The DC voltage (about 28 volts), which is the power supply of the sensor, is supplied to each part and the terminals LN and CN are connected to the sensor line l.
3 for transmitting fire information to the sensors SA and S (see FIG. 1).

In order to simplify the explanation, the point at which the sensor power supply connected between the terminals F and FG passes through the backflow prevention diode D1 is referred to as a power supply VCC (about 28 volts). V
Output regulated to a voltage level lower than CC
(About 12 volts), and the power supply VCC is
Output regulated to a voltage level lower than VCC
(About 17 volts). Further, a terminal FG connected to the sensor power supply line l2 and a terminal CN connected to the sensor line l3 are connected by a ground line GNP.

First, an operation in a multiplex signal transmission period in which a multiplex signal is transmitted and received between the fire receiver 1 and the sensor SA via the repeater 2 will be described with reference to a time chart of FIG.

From the fire receiver 1 to the repeater 2 via the multiplex signal line l1,
When a transmission switching signal with an address is input (see FIG. 3 (a)), the multiplex signal is decoded by the control means 24 via the multiplex transmission control section 22, and the photocoupler 25 of the insulated transmission circuit 25 is decoded.
Drive a. By driving the photocoupler 25a, the power supply VDD
Current flows through the resistor R1, the transistor Q1, and the photocoupler 25a to the base of the transistor Q3, so that the transistor Q3 is turned on and the transistor Q4 is turned off, whereby the base current of the transistors Q5 and Q6 is cut off, and the transistor Q5 is turned off. Power supply VC supplied to terminal LN
C and the power supply VEE also supplied to the terminal LN through the transistor Q6 are cut off. As a result, the terminal LN receives the resistor R1, the transistors Q1, Q2 and the diode D from the power supply VDD.
Power supply VDD is supplied through 2 to start a multiplex signal transmission period with the sensor SA, and each sensor connected to the sensor line l3
SA indicates that the voltage level of the sensor line 13 has dropped (the power supply VCC
From the power supply to the power supply VDD) to drive the CPUs mounted on each of them to enter a multiplex signal reception state (see FIG. 3 (c)).

The time T1 (approximately
25 ms) (this time T1 is the CP of each sensor SA)
U is provided for the rise time), control means 24
2 (see FIG. 2), a gate signal is output to the switching circuit 231a of the level conversion control section 23 (see FIG. 3 (b)), whereby the photocouplers 25b,
(In the circuit example, the function of the switching circuit 231a is provided by making the photocoupler 25b active by the gate signal of the control means 24). The multiplexed signal (multiplexed signal having an amplitude of +24 volts and −24 volts) received by the receiver 22b is transmitted to the level converter 23b through the photocoupler 25b of the insulated transmission circuit 25, and the transistor Q1 of the level converter 23b is turned on. It is driven according to the multiplex signal.

This multiplexed signal is a photocoupler 25 at +24 volts.
b is turned off and turned on at −24 volts, so that the transistor Q1 is turned off when the multiplexed signal is at +24 volts, and the power VDD supplied through the resistor R1 is changed to the Zener diode Z.
After being dropped to about 5 volts at D1, a voltage of about 5 volts is supplied to terminal LN (sensor line 13) through transistor Q2 and diode D2. Conversely, when the multiplex signal is at -24 volts, transistor Q1 is turned on. Power supply VDD is a resistor R
1, Terminal LN through transistors Q1, Q2 and diode D2
Supply a voltage of about 12 volts. Therefore, a multiplex signal having amplitudes of +24 and -24 volts is converted into a multiplex signal having an amplitude of between 5 volts and 12 volts between terminals LN and CN, and transmitted to each sensor SA.

On the other hand, the sensor SA having received the level-converted multiplex signal outputs a return signal with respect to the multiplex signal,
This return signal changes the current level by changing the impedance of the sensor line l3, and the change in the current level is converted into a current-voltage conversion circuit (hereinafter, referred to as an I / V conversion circuit) 23c of the level conversion control unit 23. The detection is performed by the following.

First, when one sensor SA sends a reply signal, the current flowing through the sensor line 13 fluctuates according to the reply signal, and the power supply
The current level supplied from VDD through the resistor R1, the transistors Q1, Q2, and the diode D2 fluctuates, and a voltage is generated across the resistor R1 in accordance with the current level fluctuation. After the voltage is amplified by the I / V conversion circuit 23c composed of the amplifier AMP1, the power supply VDD is applied to the comparator CMP1 having the reference voltage divided by the resistors R2 and R3, thereby increasing the current of the sensor line l3. "H" from comparator CMP1
On the contrary, when the current decreases, the comparator CMP1 outputs the “L” level voltage.

Here, the time T1 from the start of the transmission period of the multiplex signal
(About 25 milliseconds), the control means 24
(See Fig. 2)
25b is set to a transmission enabled state, and at this time, the photocoupler 25c is simultaneously switched to the ON state, so that the output voltage of the comparator CMP1 drives the photocoupler 25d and sends the signal to the multiplex signal transmission circuit 22A of the multiplex transmission control unit 22. The multiplexed signal from the sensor SA is level-converted and output.

When the transmission and reception of the fire information by the multiplex signal of the fire receiver 1 and each sensor SA via the repeater 2 is completed in this way, a transmission switching signal is transmitted from the fire receiver 1 to the repeater 2, The control means 24 of the repeater 2 determines the end of transmission / reception of the multiplex signal, and switches the photocouplers 25a, 25b, 25c to the off state. Thereby, contrary to the case where the multiplex signal transmission period is started, the transistor Q3 is turned on and the transistor Q4 is turned on by turning off the photocoupler 25a.
The transistors Q5 and Q6 are turned on at the same time, and the power supply VCC
And the power supply VEE is supplied to the terminal LN, and the detector line is connected to the power supply V
It becomes the voltage level of CC, and the multiplex signal transmission period ends and returns to the standby state.

Next, the operation of the alarm monitoring period in which the alarm signal of the general sensor S having no address is transmitted to the fire receiver 1 via the repeater 2 will be described with reference to FIG.

When an alarm monitoring signal with an address is input from the fire receiver 1 to the repeater 2 via the multiplex signal 11, the multiplex signal is decoded by the control means 24 via the multiplex transmission control unit 22, and the control means Reference numeral 24 reads the output voltage level of the level determination circuit 27 to determine the alarm status.

Here, when a general sensor S does not issue an alarm,
The connected terminal LN of the sensor line l3 is at the voltage level of the power supply VCC. However, when the sensor S issues an alarm, the sensor line l3 is short-circuited through the internal resistance of the sensor S.
Although the power supply VCC is lowered by the resistor R8 connected to the emitter of Q5, since the internal impedance of the power supply VEE is low,
The voltage level of the terminal LN drops to approximately VEE.

On the other hand, the level discrimination circuit 27 has a reference voltage ER (about 19 volts) obtained by dividing the power supply VCC by the resistors R4 and R5.
When the alarm is not issued and the voltage level of the detector line l3 is VCC, an "H" level alarm monitoring signal is output, but when the detector S issues an alarm, the voltage level of the detector line l3 is reduced. Since it decreases and becomes lower than the reference voltage ER of the level determination circuit 27,
An "L" level alarm discrimination signal is output. Therefore, the control means 24 determines the alert of the general sensor S from the level of the alert determination signal, transmits the alert determination signal to the fire receiver 1, and the fire receiver 1 determines the alert determination signal. Outputs a fire alarm according to. This alarm monitoring period ends with the alarm discrimination signal returned from the repeater 2.

Next, an operation for conducting a continuity test for detecting a disconnection and a short circuit of the sensor line 13 will be described with reference to the circuit example of FIG. 6. Since it is necessary to connect the terminator 4 having the circuit configuration shown in the figure,
The operation will be described with reference to the time chart of FIG.

The terminator 4 uses the reference voltage (about 4 volts) as a threshold and opens the output terminal OUT when a higher voltage level is input to the input terminal IN, and conversely outputs when the input voltage is lower than the threshold. The voltage detection circuit IC10 performs an operation of short-circuiting the terminal OUT to the ground level.

When the repeater 2 is in the standby state, the voltage level of the sensor line 13 connected to the terminals LT and CT is VCC (about 28 volts), and this voltage is depolarized by the bridge diode BD and the resistors R10 and R11 , And is applied to the input terminal IN of the voltage detection circuit IC10. Since this voltage level exceeds the threshold value (about 4 volts), the output terminal OUT is opened,
Capacitor C is fully charged through resistors R10, R12, R13 and transistor Q10.

In this state, when the repeater 2 enters a continuity test period to be described later, the voltage level VCC (about 28 volts) of the sensor line 13 is reduced to VDD (about 12 volts) for a time T (about 30 milliseconds). (See FIG. 8 (a)), resistors R10 and R11 of the terminator 4
, The output terminal OUT of the voltage detection circuit IC10 is short-circuited to the ground level, and the electric charge charged in the capacitor C is short-circuited through the output terminal OUT, the diode D and the resistor R13. (Approximately 3 milliseconds). And, after the time T, the detector line l3 becomes the voltage level.
When the voltage returns to VCC, the voltage level of the input terminal IN of the voltage detection circuit IC10 exceeds the threshold, so the output terminal OUT is opened and the capacitor C is connected to the resistors R10, R12, R13 and the transistor Q.
Charged through 10. Since the charging time 2T is longer than the discharging time (about 60 milliseconds), during this time 2T, the transistors Q10 and Q11 are turned on, the sensor line l3 is terminated by the resistor R14, and the termination current (about 30mA) is reduced. Flow (see FIG. 8 (b))
The voltage level of the detector line 13 does not rise to VCC, and V2 (about 1
7 volts) and transistor Q after time 2T
10, when Q11 turns off, the voltage rises again to the same VCC voltage level as in the standby state (see the eighth (a)).

That is, the terminator 4 detects a rise in the voltage level of the sensor line l3 and performs a function of flowing a termination current for a predetermined time. In the present embodiment, the termination current and the general sensor are used. The alarm current at the time of alarm is set equal.

The disconnection detection in the case where such a terminator 4 is connected to the repeater 2 and a continuity test of the sensor line 13 is performed will be described.
Referring to the circuit example of FIG. 6 and the time chart of FIG. 9, when a continuity test switching signal is input from the fire receiver 1, first, the repeater 2 determines the switching signal by the control means 24 in the repeater 2. And the photocoupler 25a of the insulated transmission circuit 25
(Approximately 30 milliseconds).
reference). As a result, similarly to the transmission period described above, the transistor Q3 is turned on, the transistor Q4 is turned off, and the transistors Q5 and Q6 are turned off, so that the power supply VCC and the power supply VEE supplied to the terminal LN are cut off, Power supply VDD (approximately) is connected to LN through resistor R1, transistors Q1, Q2 and diode D2.
12 volts) and after the time T has elapsed, the control means
Since the ON state of the photocoupler 25a is released by the switch 24, the transistors Q5 and Q6 operate to supply the power VCC to the terminal LN again. However, since the terminating current (about 30 mA) flows through the terminator 4 connected to the sensor line l3, the voltage at the terminal LN becomes V2 (about 17 volts) due to the voltage drop of the resistor R8 connected to the emitter of the transistor Q5. Stays.

Then, when the time 2T (approximately 60 milliseconds) elapses, the termination current by the terminator 4 is cut off, and the voltage level of the terminal LN returns to the level of the power supply VCC again. On the other hand, the level discriminating circuit 27 of the repeater 2 has a reference voltage obtained by dividing the power supply VCC by the resistors R4 and R5.
ER (approximately 19 volts), monitors the voltage level of the terminal LN, and transmits a continuity monitoring signal to the control means 24 through the photocoupler 25e. The output level of the level determination circuit 27 is monitored after the lapse of T / 2 (first monitoring) and after the lapse of time 2T (second monitoring).

Therefore, when the sensor line 13 is normally connected to the terminator 4, the output level of the level discrimination circuit 27 after the elapse of the time T / 2 and after the elapse of the time 2T is both "L" level, and the control is performed. The means 24 determines that the detector line 13 is in a normal state based on these conduction monitoring signals, and returns a normal signal of the conduction test to the fire receiver 1 side.

However, when a disconnection occurs in the middle of the sensor line l3, the terminal current by the terminator 4 does not flow.
After returning to the VCC level, the level discriminating circuit 27 outputs an "L" level detection signal during the first monitoring, but outputs an "H" level detecting signal during the second monitoring. Then, the level of the conduction monitoring signal at the time of the first monitoring and the second monitoring is read to determine the disconnection, thereby outputting a disconnection occurrence signal to the fire receiver 1 side.

Next, the short circuit detection in the case where the terminator 4 is similarly connected to the sensor line 13 of the repeater 2 and the continuity test of the sensor line 13 is performed will be described with reference to the circuit example of FIG. 6 and the time chart of FIG. However, when a short circuit occurs in the sensor line l3, a short-circuit protection operation for immediately preventing an excessive current supplied from the power supply VCC and the power supply VEE is necessary. It will be explained first.

Normally, when the repeater 2 is not transmitting / receiving a multiplex signal to / from the fire receiver 1, a power supply VCC (about 28 volts) is applied between the terminals LN and CN connected to the detector line l3. Therefore, if a short circuit occurs in the sensor line l3 for any reason, the current level will increase sharply and the terminal L
There is a risk that the voltage between N and CN decreases, the power consumption of each part of the circuit increases, and parts are destroyed or the sensor line 13 is burned.

In order to avoid such inconvenience, the voltage level of the terminal LN is continuously set for a predetermined time determined by the capacitor C1 and the resistor R6 of the short-circuit detection and holding circuit 28 for a predetermined level (in this embodiment, Zener When the voltage drops below the level determined by the diode ZD2 (about 5 volts), the transistor Q7 is turned on and the transistor Q8 is turned on. As a result, the transistor Q4 is turned off, the bases of the transistors Q5 and Q6 are opened to cut off the supply of the power supply VCC and the power supply VEE to the terminal LN, and at the same time, the diode D5 connected to the collector of the transistor Q8 and the resistor R9. , The voltage level of the terminal LN is forcibly reduced to a predetermined level (a level low enough not to cause damage to the circuit components of the repeater 2 or to burn out the sensor line 13 due to the occurrence of a short circuit), and the transistor Q7. Is self-holding to perform a short-circuit protection operation. When this short-circuit protection is activated, transistor Q7
Turns on the transistor Q9 to lower the reference voltage ER of the level determination circuit 27 to approximately zero volts.
The level determination circuit 27 continuously outputs an "H" level conduction monitoring signal.

As described above, when the short circuit occurs in the sensor line l3 and the short circuit protection operation is being performed, and when the continuity test switching signal is input from the fire receiver 1 to the repeater 2, the case of the disconnection detection is different. Similarly, the control means 24 turns off the transistors Q5 and Q6.However, the transistors Q5 and Q6 are already turned off by short-circuit protection, the voltage of the terminal LN has dropped to a predetermined level, and the level discrimination circuit 27
Output an "H" level (see FIG. 9 (d)). Therefore, the time T / 2 after the input of the conduction switching signal
At the time of the first monitoring after the lapse of time, the output level of the level determination circuit 27 becomes "H" level. Since the state is continued, the level determination circuit 27 continues to output the "H" level detection signal even during the second monitoring after the lapse of time 2T. The occurrence of a short circuit is determined by the control means determining the "H" level conduction monitoring signal at the time of the first monitoring and the second monitoring, and a short circuit occurrence signal is output to the fire receiver 1 side.

On the other hand, on receiving the short-circuit occurrence signal, the fire receiver 1 transmits a short-circuit release signal to the repeater 2, and the control means.
The relay (not shown) is driven for a predetermined time by 24, the self-holding of the transistor Q7 is released by the relay contacts ry1a and ry1b, and the sensor line 13 is opened.
Then, when the short circuit protection is activated again when the relay is released and the sensor line 13 is connected, a short circuit occurrence signal is again sent to the fire receiver 1 by the same operation as described above, and this operation is performed. A predetermined number of times (3 in this embodiment)
After the repetition, the fire receiver 1 determines that the sensor line 13 is short-circuited and issues a notification.
Therefore, even if a short circuit occurs in the sensor line l3, the short circuit protection is activated immediately to prevent the destruction of parts and the burnout of the detector line l3, and after the occurrence of the short circuit is repeatedly confirmed on the fire receiver 1 side. Since the short-circuit notification is performed, the reliability of the system can be improved.

In the above description, the multiplex signal transmission period, the alarm monitoring period, and the continuity test period are individually provided, and the switching operation is performed by a signal from the fire receiver 1. The present invention is not limited to the configuration, and various countermeasures such as, for example, performing the continuity monitoring operation after performing the alert monitoring operation are possible.

According to the present invention as set forth in claim 1, a repeater having a function of performing only level conversion of a multiplex signal output from a fire receiver and a sensor is provided. By enhancing the signal processing function, it is possible to provide a monitoring system with reduced cost capable of detecting an alarm from a detector to which an address is set.

According to the second aspect of the present invention, a function of transmitting an alarm signal of a general sensor is further added, and a fire monitoring system with an increased function can be realized without complicating the configuration of the repeater. .

According to the fire monitoring system of the present invention as set forth in claims 3 and 4, the function of each repeater is reduced to signal level conversion and relay transmission, and the signal processing function is concentrated on the fire receiver, so that the system design is improved. And a fire monitoring system that can reduce costs.

According to the fire monitoring system of the present invention, it is possible to easily design a system capable of detecting not only a sensor to which an address is set but also a sensor to which an address is not set, and to reduce the cost. A fire monitoring system is realized.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a fire monitoring system according to the present invention (a fire monitoring system according to claim 3), and FIG. 2 is a relay having a function of detecting an alarm of a detector to which an address is added. Block diagram showing the configuration of the internal circuit of the device (Claim 3)
FIG. 3 is a time chart showing the relationship between the transmission switching signal sent from the fire receiver side and the multiplexed signal sent to the sensor line of the repeater (claim 1). FIG. 4 is a block diagram showing a configuration of an internal circuit of a repeater having a function of detecting an alarm of a detector to which an address is not added. FIG. 5 is a block diagram showing a configuration of an internal circuit of a repeater having a function of detecting disconnection and short circuit of a sensor line, and FIG. 6 is a configuration of an internal circuit of the repeater. FIG. 7, FIG. 7 is a circuit configuration diagram of the terminator, FIG. 8 is a time chart for explaining the operation thereof, FIG. 9 is a time chart showing a control procedure of a continuity test of the sensor line performed on the repeater side, FIG. 10 is a system configuration diagram of a conventional fire monitoring system. Explanation of References [Description of References] l1 ... Multiple signal lines l2 ... Detector power supply line l3 ... Detector line SA ... Detector with address S ... Detector without address 1 ... Fire reception Unit 2 repeater 11 multiplex transmission control unit 12 control unit 13 fire alarm unit 14 detector power supply 21 address setting unit 22 multiplex transmission control unit 23 level conversion control unit 23a Switching circuit 23b Level conversion circuit 23c Current / voltage conversion circuit 24 Control means 25 Insulated transmission circuit

Claims (5)

(57) [Claims] 1. A fire monitoring system comprising a repeater to which a plurality of detectors each having a different address are connected to a detector line and to which an address is assigned, connected to a fire receiver through a multiplex signal line. In the above, a transmission switching signal of a specific multiplex transmission level specifying a repeater address is transmitted from the fire receiver side to the repeater side via a multiplex signal line by a polling method, and the relay receiving the switching signal is transmitted. On the sensor side, following the switching signal, the monitor signal specified by the sensor address transmitted from the fire receiver at the specific multiplex transmission level via the multiplex signal line is changed to a level corresponding to the sensor line. Convert,
The relay signal is sent out to the detector line as it is, and the return signal returned from the detector receiving the monitoring signal to the detector line is converted again to a specific multiplex transmission level at the repeater side and returned to the fire receiver side. Finally, the fire receiver decodes the return signal sent back through the multiplex signal line in this manner, thereby issuing the alarms of the sensors connected to the sensor lines of the respective repeaters. A fire monitoring method using multiplex transmission characterized in that a fire alarm can be detected for each sensor. 2. The fire monitoring method according to claim 1, wherein a specific multiplex transmission level in which a repeater address is specified from the fire receiver side to the repeater side via a multiplex signal line by a polling method. After receiving the monitoring signal, the repeater side determines the alarm of the sensor based on the fluctuation of the voltage level occurring in the sensor line derived from each of the monitoring signals, and then performs the specific multiplex transmission again. After converting it into a level response signal and returning it to the fire receiver side, finally, the fire receiver side decodes the return signal returned via the multiplex signal line in this way, thereby A fire monitoring method using multiplex transmission, wherein alarms of a sensor connected to a sensor line of a repeater and having no address set can be detected in units of the sensor line. 3. A fire monitoring system comprising: a plurality of detectors each having a different address connected to a detector line; and an assigned repeater connected to a fire receiver through a multiplex signal line. The fire receiver monitors the repeaters in the system and the sensors connected to the sensor lines of each of these repeaters,
When a sensor is issued, an abnormal signal is issued. For this purpose, it is connected to each repeater in the system via a multiplex signal line, and these repeaters and each repeater are connected. In order to monitor the sensor connected to the sensor line, a transmission switching signal of a specific multiplex transmission level designating a repeater address and a monitoring signal of a specific multiplex transmission level set with the sensor address are transmitted as described above. A multiplex transmission control unit for transmitting to the multiplex signal line by a polling method and receiving a return signal of a specific multiplex transmission level returned from the repeater and the sensor, and the multiplex according to a preset control program. Control means for operating a transmission control section, decoding a multiplex signal including a return signal received by the multiplex transmission control section, and performing necessary processing; and A fire alarm means for receiving a fire detection signal sent from the control means and generating an alarm signal when the information is determined; and a relay power supply line connected to each of the repeaters in the system. And a sensor power supply for supplying a power of a level necessary for the alarming operation of the above, wherein the relay connects detectors set to different addresses to the sensor lines derived from each of the relays, and receives the fire. The monitor signal of the specific multiplex transmission level set with the sensor address sent from the device is converted into a level corresponding to each sensor line, sent out to the sensor line as it is, and returned from the sensor. The return signal is converted into a specific multiplex transmission level, and is returned to the fire receiver. For this reason, an address setting unit for setting an address necessary for transmission of the multiplex signal, A transmission switching signal of a specific multiplex transmission level and a monitor signal designated by a sensor address are connected to the multiplex signal line and transmitted to and from the fire receiver, and a return signal of a specific multiplex transmission level is received. A multiplex transmission control unit for transmitting a signal, a detector line for supplying a detector power supplied from the detector power source of the fire receiver to the detector line, and the multiplex signal control unit monitoring the detector. Activated when a monitor signal of a specific multiplex transmission level designated by a sensor address is received, the monitor signal is converted to a level corresponding to the sensor line, sent to the sensor line, and Receiving a return signal from the sensor connected to the device line and transmitting the signal to the multiplex signal control unit; and operating the multiplex transmission control unit according to a preset control program. In addition, the multiplex transmission control unit includes a control unit that decodes a multiplex signal including a monitoring signal received by the multiplex transmission control unit, performs necessary processing, and activates the level conversion control unit; Using a multiplex transmission, comprising an insulated transmission circuit that enables transmission and reception of signals between the level conversion control section and the control section configured by Monitoring system. 4. A sensor power supply transmitted from said control means when said multiplex transmission control unit receives a transmission switching signal of a specific multiplex transmission level transmitted from a fire receiver. By the cutoff signal,
A switching circuit that shuts off the sensor power supplied to the sensor line; and a switching circuit that operates with a predetermined time delay after the sensor power is shut off by the switching circuit, and includes a switching circuit that operates from the multiplex transmission control unit. A level conversion circuit that converts a specified monitoring signal of the sensor address transmitted through the insulated transmission circuit following the transmission switching signal to a level corresponding to the sensor line, and sends the signal to the sensor line as it is, After the monitoring signal designated by the sensor address is transmitted to the sensor line whose sensor power is cut off by the level conversion circuit, the fluctuation of the current level flowing through the sensor line is converted into a voltage signal. 4. The multiplex transmission according to claim 3, further comprising a current / voltage conversion circuit for sending the multiplex transmission control unit to the multiplex transmission control unit via the insulated transmission circuit. Fire monitoring system. 5. The fire monitoring system using multiplex transmission according to claim 1, further comprising a function of detecting an alarm from a detector having no address connected to a detector line derived from the repeater. For this purpose, the repeater further includes a level discriminating circuit for discriminating a voltage level occurring in the sensor line when receiving a monitoring signal of a specific multiplex transmission level from the fire receiver by a polling method. A fire monitoring system using multiplex transmission according to claim 3.