JP6800776B2 - Repeater - Google Patents

Description

The present invention relates to a repeater used in a monitoring system such as a fire alarm system or a security system, and more particularly to a technique effective for use in a repeater having a transmission line short-circuit function and a relay control function.

Conventionally, a fire alarm system has been installed inside the building to notify the occurrence of a fire. The fire alarm system receives signals from terminal devices such as fire transmitters equipped with fire detectors and push button switches, fire alarm bells, indicator lights, smoke exhaust devices, and fire shutters, as well as signals from detectors and transmitters. A receiver that outputs a signal for operating a bell, an indicator light, etc., and a terminal device and a receiver that receives a signal from a detector and transmits a signal to a fire receiver, a bell, a smoke exhaust device, etc. It is composed of repeaters that convert signals between them. Here, the bell, the indicator light, and the repeater are generally configured to operate with the electric power supplied from the receiver via the transmission line.

In addition, the fire alarm system detects a short circuit when the transmission line is short-circuited and electrically disconnects the transmission line on the downstream side so that all the detectors can be avoided from malfunctioning. Some have an SCI (Short Circuit Isolator).
On the other hand, in recent years, a crime prevention system that combines an authentication device using an ID card and an electric lock to enhance the security of an office or an apartment house has become widespread. There is also a system in which a fire alarm system and a crime prevention system are integrated and an electric lock is connected to a repeater of the fire alarm system.

In equipment that employs a system equipped with a fire monitoring function and a security function using an electric lock as described above, there is a risk that the receiver will stop operating due to a power outage or the like in the event of a fire and the system will go down. At that time, if the system goes down while the electric lock is locked, it may hinder the smooth evacuation behavior of the human inside. Therefore, such a system is required to have a fail-safe function to release the locked state of the electric lock immediately before the system goes down. Therefore, in a system in which an electric lock is connected to a repeater, it is necessary to provide the repeater with a fail-safe function as described above.

Some receivers are equipped with an auxiliary power supply (battery) so that they can operate even during a power outage, but if the power outage lasts for a long time, the power supply voltage will gradually drop and the terminal will be connected via a transmission line. The voltage supplied to the equipment and repeater also drops, leading to a system down.
Conventionally, in a system equipped with a detector for fire or gas and a security device, the security device has a plurality of preset security levels based on the detected temperature, smoke concentration, and carbon monoxide concentration. An invention has been proposed in which any of the above is determined and the electric lock is unlocked when the determined security level is high (for example, Patent Document 1). Further, as an invention relating to a fire alarm system provided with a repeater or SCI, for example, there is one described in Patent Document 2.

JP-A-2002-8165 JP-A-2007-323197

By the way, in order to lock and release the locked state of an electric lock in a system having a security function, an actuator such as a solenoid or a motor and an electromagnetic relay for passing a current through the actuator are generally used. Then, the electromagnetic relay for operating the electric lock needs to maintain its state even if the power supply or the monitoring system goes down.

On the other hand, the present inventors have an SCI function that detects a short circuit when the transmission line is short-circuited and electrically disconnects the transmission line on the downstream side (short-circuited side) to prevent the entire transmission line from failing. We investigated a repeater with a fail-safe function that unlocks the electric lock when the transmission voltage drops. As a result, if the fail-safe function is activated when the transmission voltage drops, the relay operates only when the receiver stops operating, and the transmission line is unlocked even though the electric lock is desired to be unlocked. It has become clear that there is a problem that the relay operates and the locked state of the electric lock is released even when the electric lock is short-circuited.

The present invention has been made by paying attention to the above-mentioned problems, and an object of the present invention is that even if a relay is used for operating an electric lock, the relay does not operate when the transmission line is short-circuited. An object of the present invention is to provide a relay that can activate a relay to release the locked state of an electric lock when the receiver stops operating.

In order to solve the above problems, the present invention
A terminal device to which one or more terminal devices are connected, operates by receiving power supplied from the receiver via a transmission line connected to the receiver, and is connected to the terminal device. A repeater having a function of transmitting a signal received from the receiver via the transmission line.
A voltage monitoring circuit that monitors the voltage of the transmission line and
A transmission voltage drop determination circuit that distinguishes between a short circuit of the transmission line and a decrease in voltage supplied from the receiver based on the output of the voltage monitoring circuit and generates a control signal.
A latch type relay for operating a predetermined terminal device in the first state and the second state is provided.
When the transmission voltage drop determination circuit determines that the transmission line is short-circuited, it generates a control signal that causes the latch-type relay to be in the state before voltage drop detection, and the voltage drop supplied from the receiver causes the voltage drop. When it is determined that there is, the latch type relay is configured to generate a control signal for operating the latch type relay in a state different from the state before the voltage drop detection.

According to the above configuration, even if a latch type relay is used to operate a terminal device such as an electric lock, the relay does not operate when the transmission line is short-circuited, the receiver stops operating, and the receiver supplies the signal. When the voltage is reduced, the relay is activated and the fail-safe function is activated to change the terminal device to the safe state.

Here, preferably, the transmission voltage drop determination circuit is the latch type when the voltage of the transmission line does not recover even after a predetermined time has elapsed after the voltage monitoring circuit detects the voltage drop of the transmission line. It is configured to generate a control signal that operates the relay in a state different from the state before the voltage drop detection.
According to this configuration, in a system provided with an SCI (short circuit isolator) function on the transmission line, the voltage of the transmission line is restored by SCI even if the transmission line is short-circuited, so that a voltage drop in the transmission line is detected. After that, if the voltage of the transmission line has not recovered after a predetermined time has elapsed, the receiver has stopped operating, so a control signal is generated to operate the latch-type relay in a state different from the state before the voltage drop detection. By doing so, the fail-safe function works and the terminal device can be changed to the safe state.

Further, preferably, a short-circuit protection circuit which is connected in series with the transmission line and cuts off the transmission line when the voltage of the transmission line drops based on the output of the voltage monitoring circuit is provided.
The short-circuit protection circuit cuts off the transmission line and cuts off the transmission line when the voltage monitoring circuit determines that the transmission line is short-circuited or the voltage supplied from the receiver is lowered. Try to maintain the state.
According to this configuration, since the repeater has an SCI (short circuit isolator) function, the circuit for detecting the voltage drop of the transmission line can be shared between the SCI function circuit and the fail-safe function circuit. By simply adding a simple circuit to the repeater, the number of SCIs provided on the transmission line can be reduced.

Further, preferably, the predetermined terminal device is an electric lock.
According to such a configuration, when the receiver is stopped, the latch type relay is activated, the fail-safe function is activated, and the locked state of the electric lock can be released.

According to the present invention, even if a relay is used for operating the electric lock, the relay does not operate when the transmission line is short-circuited, and the relay operates when the receiver stops operating to lock the electric lock. There is an effect that a relay that can release the state can be realized.

It is a system block diagram which shows the configuration example of the fire alarm system which is effective by applying the repeater which concerns on this invention. It is a block diagram which shows the schematic structure of SCI (short circuit isolator). It is a block diagram which shows the schematic structure of one Example of the repeater which concerns on this invention. The operation of the repeater of the embodiment is shown, where (A) is a timing chart when a short circuit occurs in the transmission line, and (B) is a timing chart when the transmission voltage drops. The operation of the repeater in another embodiment is shown, where (A) is a timing chart when a short circuit occurs in the transmission line, and (B) is a timing chart when the transmission voltage drops.

Hereinafter, an embodiment of a repeater according to the present invention and a fire alarm system using the repeater will be described with reference to the drawings.
FIG. 1 shows a configuration example of an effective fire alarm system to which the repeater according to the present invention is applied.
The fire alarm system shown in FIG. 1 is connected to a fire receiver 10 that receives a signal from a detector or a transmitter and outputs a signal for operating a bell, an indicator lamp, or the like, and the fire receiver 10. A loop-shaped transmission line 20 and a plurality of fire detectors 31, a fire transmitter 32, SCI 40, and a repeater 50 provided in the middle of the transmission line 20 are provided, and the repeater 50 includes a bell 61 and a smoke exhaust device 62. Terminal devices such as a fire shutter 63 and an electric lock 64 are connected.

The transmission line 20 is composed of two wires (a signal line and a common line). An operating voltage is supplied from the fire receiver 10 to the fire detector 31, SCI 40, and repeater 50 via the transmission line 20. In the system shown in FIG. 1, the transmission lines 20 are arranged so as to form a loop when viewed from the fire receiver 10, but a terminator is provided at the end opposite to the fire receiver 10 in one direction. Some systems are arranged as transmission lines.

FIG. 2 shows a schematic configuration of the SCI 40. In FIG. 2, L1 is one wiring (signal line) constituting the transmission line 20, and L2 is the other wiring (common line) constituting the transmission line 20. The SCI 40 monitors a pair of switch elements 41a and 41b provided in series with the wiring L2, diodes 42a and 42b provided in parallel with the switch elements 41a and 41b, and a switch element 41a by monitoring the voltage of the wiring L1. , 41b includes a control circuit 43 that generates a signal for controlling the on / off state, a constant voltage circuit 44 that receives a voltage from the wiring L1 of the transmission line 20 and generates an operating voltage of the control circuit 43, and the like. The control circuit 43 can indirectly monitor the voltage of the wiring L1 by monitoring the voltage from the constant voltage circuit 44.

With the above configuration, for example, when a short-circuit accident occurs on the transmission line 20 at a location indicated by reference numeral A in FIG. 1, the voltage of the wiring L1 of the transmission line 20 drops, so that the control circuit 43 is short-circuited. Is detected, and the switch elements 41a and 41b are turned off. Then, since the short-circuited portion is disconnected from the fire receiver 10, the voltage of the wiring L1 of the transmission line 20 on the opposite side of the short-circuited portion A rises, and a current flows through the diode 42a, so that the short-circuited portion A sandwiches the SCI 40. The transmission line on the opposite side returns to a communicable state, and the detector and repeater on the transmission line on the opposite side become operational and can continue to operate. The process from the occurrence of a short circuit to the return to a communicable state can be completed in a few ms (milliseconds).

As shown in FIG. 2, when the transmission lines 20 are arranged so as to form a loop, voltage is also supplied from the fire receiver 10 from the opposite side of the transmission lines 20, so that a short-circuited portion sandwiches the SCI 40. The sensor on the transmission line on the opposite side of A also becomes operational.
In the SCI 40 of FIG. 2, FETs (field effect transistors) can be used as the switch elements 41a and 41b, and in that case, the parasitic diode existing on the substrate of the FET is used as the diodes 42a and 42b in FIG. Can be used as.

Next, the configuration and function of the repeater 50 will be described with reference to FIG.
As shown in FIG. 3, the repeater 50 of this embodiment has a built-in CPU (central processing unit) and memory such as ROM and RAM, and operates according to a program stored in the ROM from an MCU (microcomputer unit) or the like. The constant voltage circuit 52 as a power supply device that receives the voltage from the wiring L1 of the transmission line 20 and generates the operating voltage of the internal circuit including the control circuit 51, and the voltage of the wiring L1 of the transmission line 20. A transmission voltage monitoring circuit 53 for monitoring is provided. The transmission voltage monitoring circuit 53 can be composed of, for example, a comparator or an AD conversion circuit, and the output of the transmission voltage monitoring circuit 53 is input to the control circuit 51 to determine whether or not the transmission voltage is equal to or lower than a predetermined voltage. Will be done.

Further, the relay 50 of the present embodiment is a terminal device such as a bell 61, a smoke exhaust device 62, a fire prevention shutter 63, etc., in which a signal received from the fire receiver 10 via the transmission line 20 is connected to the relay 50. A communication interface circuit 54 as a signal transmission circuit to be transmitted to, a short-circuit protection circuit 55 composed of a pair of switch elements 55a and 55b similar to SCI and diodes 56a and 56b, and a fail-safe signal for the electric lock 64 are output. A relay drive circuit (a pair of electromagnetic solenoids) 57a and contacts 57b are provided. The relay output circuit 57 is composed of a relay drive circuit (a pair of electromagnetic solenoids) 57a and a contact 57b. In this embodiment, a latching relay is used as the relay output circuit 57.

When the control circuit 51 detects a short circuit in the transmission line 20, the switch elements 55a and 55b are controlled to the off state in the same manner as the SCI. On the other hand, the relay output circuit 57 is configured to be controlled based on the determination result of the transmission voltage by the control circuit 51. The short-circuit protection function of the transmission line 20 can be omitted. As will be described later, the repeater 50 of this embodiment has a function of distinguishing between a short circuit of the transmission line 20 and a decrease in the transmission voltage. Therefore, when a short circuit of the transmission line 20 is detected, the short circuit protection circuit 55 By activating SCI, the function of SCI can be added without separately providing a circuit for controlling the short-circuit protection circuit 55, whereby the number of SCIs provided independently can be reduced.

Further, the repeater 50 of this embodiment is provided with a setting device 58 that can switch whether to enable or disable the fail-safe function by the control circuit 51 and the relay output circuit 57 from the outside.
Due to the fail-safe function of the repeater 50 of this embodiment, the latching relay operates when the battery of the fire receiver 10 drops and the operation stops, and the voltage supplied via the transmission line drops. The locked state of the electric lock can be released. Moreover, in the relay 50 of this embodiment, when the transmission line 20 is short-circuited and the transmission voltage temporarily drops, the latching relay does not operate and the locked state of the electric lock is not released. It has become.

Next, the control operation of the repeater 50 when the voltage of the transmission line is lowered by the control circuit 51 will be described with reference to the timing chart of FIG. In FIG. 4, (A) is when a short-circuit accident occurs in the transmission line, and (B) is when the transmission voltage from the fire receiver 10 drops.
In the repeater 50 of this embodiment, as shown in FIGS. 4A and 4B, the transmission voltage drops below the predetermined detection level VthL, and the output of the voltage monitoring circuit (comparator) 53 is from high level to low level. If the output of the transmission voltage monitoring circuit (comparator) 53 remains at a low level even after a predetermined time Td1 elapses after the control circuit 51 detects (timing t1) that the signal has changed to, the control of the short-circuit protection circuit 55 The signal is turned off to turn off the switch elements 55a and 55b of the short-circuit protection circuit 55, and the transmission line on the downstream side is disconnected (timing t2).

More specifically, when the output of the voltage monitoring circuit (comparator) 53 changes from a high level to a low level (t1), a voltage check request is generated by the control circuit 51 to check the output of the transmission voltage monitoring circuit 53. , The voltage check request is generated again after T1 (for example, 0.5 ms), and when it is confirmed that the output of the transmission voltage monitoring circuit 53 is low level twice in succession, the short circuit protection circuit 55 of the short circuit protection circuit 55 is confirmed after T2 (for example, about 1 ms). The control signal is turned down and the transmission line on the downstream side is disconnected (timing t2).

When a short circuit occurs, after the transmission line is disconnected by short circuit protection, the transmission voltage recovers if the vicinity of the own station is not short-circuited. Then, when the transmission voltage monitoring circuit 53 detects that the return detection level VthH has been exceeded, the output changes from a low level to a high level (t3), and in response to this, a voltage check request is generated by the control circuit 51. When the output of the transmission voltage monitoring circuit 53 was checked, a voltage check request was generated again after T1, and it was confirmed that the output of the transmission voltage monitoring circuit 53 was at a high level twice in a row, a short circuit occurred in the transmission line. Judged. Therefore, the relay control pulse UP is not generated, and the relay output remains at the low level (electric lock: closed side).

On the other hand, when the predetermined time Td2 elapses after the control signal of the short-circuit protection circuit 55 is turned off, the switch elements 55a and 55b of the short-circuit protection circuit 55 are turned off, and the transmission line on the downstream side is disconnected (timing t2). At (timing t4), as shown in FIG. 4B, when it is detected that the output of the transmission voltage monitoring circuit (parallelizer) 53 is at a low level twice in a row, the transmission voltage is lowered. Then, the control signal UP for the relay output circuit 57 is started. As a result, the relay output changes to a high level, the latching relay operates, and the electric lock is unlocked. The predetermined time Td2 may be set to a time slightly longer than the operation required time (30 ms) of the short-circuit protection circuit 55.

(Second Example)
Next, a method of controlling the output circuit when the terminal device connected to the repeater 50 is an alarm device such as a bell will be described. In the case of such a device, the control logic is opposite to that of the above embodiment, and if a short circuit occurs in the transmission line during the sound ringing, the sound ringing is continued, while the fire receiver goes down during the sound ringing. When the transmission voltage drops due to the above, control to stop the ringing is required. Further, in the case of an alarm device such as a bell, it is controlled by turning on / off a voltage output such as 24V, instead of controlling by the contact output by the relay of the above embodiment. A latching relay is used to turn this voltage output (24V) on and off.

FIG. 5 shows an example of a timing chart of the control operation of the repeater 50 when the transmission voltage drops in the repeater 50 to which the above equipment is connected. In FIG. 5, (A) is when a short-circuit accident occurs in the transmission line, and (B) is when the transmission voltage from the fire receiver 10 drops.
In this embodiment, as shown in FIGS. 5A and 5B, the transmission voltage drops below the predetermined detection level VthL, and the output of the voltage monitoring circuit (comparator) 53 changes from a high level to a low level. If the output of the transmission voltage monitoring circuit (comparator) 53 remains at a low level even after a predetermined time Td1 elapses after the control circuit 51 detects (timing t1), the control signal of the short-circuit protection circuit 55 is shut down. The switch elements 55a and 55b of the short-circuit protection circuit 55 are turned off, and the transmission line on the downstream side is disconnected (timing t2).

When a short circuit occurs during sound ringing, the transmission line is disconnected by short circuit protection, and then the transmission voltage recovers if the vicinity of the own station is not short-circuited. Then, when the transmission voltage monitoring circuit 53 detects that the return detection level VthH has been exceeded, the output changes from a low level to a high level (t3), and in response to this, a voltage check request is generated by the control circuit 51. When the output of the transmission voltage monitoring circuit 53 was checked, a voltage check request was generated again after T1, and it was confirmed that the output of the transmission voltage monitoring circuit 53 was at a high level twice in a row, a short circuit occurred in the transmission line. Judged. Therefore, the relay control pulse UP is not generated, the output circuit control signal remains at a high level, and the latching relay remains closed (alarm: acoustic ringing).

On the other hand, when the transmission voltage drops during the acoustic ringing, the control signal of the short-circuit protection circuit 55 is turned off, the switch elements 55a and 55b of the short-circuit protection circuit 55 are turned off, and the transmission line on the downstream side is disconnected ( After the timing t2), when the predetermined time Td2 has elapsed (timing t4), as shown in FIG. 5 (B), it is detected that the output of the transmission voltage monitoring circuit (comparator) 53 is at a low level twice in a row. If this is the case, it is determined that the transmission voltage has dropped, and the control signal LP for the relay output circuit 57 is started up. As a result, the output circuit control signal changes to a low level, the latching relay is switched to the open side, and the alarm stops sounding.

Although the present invention has been described above based on the embodiment, the present invention is not limited to that of the above embodiment. For example, in the fire alarm system of the above embodiment, only the fire detector is connected to the transmission line as a detection, but the gas detection that detects toxic gas in addition to the fire detector (including smoke detection) is shown. The vessel may be connected.
Further, in the above embodiment, an electric lock has been described as an example of a terminal device subject to fail-safe control, but the target terminal device is not limited to the electric lock, and may be other equipment or devices such as a fire door. Is also good.

Further, in the above embodiment, the case where the present invention is applied to a fire alarm system provided with a fire receiver has been described, but the present invention is not limited to the fire alarm system and is a monitoring target such as a disaster prevention monitoring system and a security system. A system including a plurality of terminal devices arranged in an area and a receiver for receiving a signal from the terminal devices can be widely used.

10 Receiver 20 Transmission line 31 Fire detector 32 Transmitter 40 SCI (Short circuit isolator)
50 Repeater 51 Control circuit 53 Transmission voltage monitoring circuit (comparator)
55 Short-circuit protection circuit 64 Terminal equipment (electric lock)

Claims (4)

A terminal device to which one or more terminal devices are connected, operates by receiving power supplied from the receiver via a transmission line connected to the receiver, and is connected to the terminal device. A repeater having a function of transmitting a signal received from the receiver via the transmission line.
A voltage monitoring circuit that monitors the voltage of the transmission line and
A transmission voltage drop determination circuit that distinguishes between a short circuit of the transmission line and a decrease in voltage supplied from the receiver based on the output of the voltage monitoring circuit and generates a control signal.
A latch type relay for operating a predetermined terminal device in the first state and the second state is provided.
When the transmission voltage drop determination circuit determines that the transmission line is short-circuited, the transmission voltage drop determination circuit generates a control signal that causes the latch-type relay to be in the state before voltage drop detection, and the voltage drop supplied from the receiver causes the voltage drop. A repeater characterized in that it is configured to generate a control signal that operates the latch-type relay in a state different from the state before voltage drop detection when it is determined to be present. The transmission voltage drop determination circuit sets the latch type relay before the voltage drop detection when the voltage of the transmission line does not recover even after a predetermined time has elapsed after the voltage monitoring circuit detects the voltage drop of the transmission line. The repeater according to claim 1, wherein the repeater is configured to generate a control signal that operates in a state different from that of the above. A short-circuit protection circuit that is connected in series with the transmission line and cuts off the transmission line when the voltage of the transmission line drops based on the output of the voltage monitoring circuit is provided.
The short-circuit protection circuit cuts off the transmission line and cuts off the transmission line regardless of whether the voltage monitoring circuit determines that the transmission line is short-circuited or that the voltage supplied from the receiver is low. The repeater according to claim 1 or 2, characterized in that the state is maintained. The repeater according to any one of claims 1 to 3, wherein the predetermined terminal device is an electric lock.

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