JP2008219277A - Communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device for stopping power supply of a feeder for safety, without using a special feeder, when faults occur in and outside the device. <P>SOLUTION: A communication device 2 receives power supply from a router 3 as a general feeder by POE, through a communication power line 4. The router 3 stops power supply to the communication device 2, if disconnection of the communication power line 4 is detected. A control portion 23 decreases an input current value of a power receiving circuit 25 and increases an input impedance of the power receiving circuit 25, so that the router 3 recognizes that the communication power line 4 is disconnected, when alarm information warning of risks or faults is received from a detector 11, when communication with the detector 11 or the router 3 is stopped, or when a comparator 28 detects that excess current flows at a power supply circuit 26. As a result, the router 3 stops power supply to the communication device 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication device that receives and communicates power supplied from outside via a communication power line.

Conventionally, there has been proposed a communication device that receives power supply by POE (Power Over Ethernet (registered trademark)) (see Patent Document 1).
Such a communication apparatus is supplied with power via an Ethernet (registered trademark) cable from a power supply apparatus having a communication relay function such as a router or a gateway. The communication device that has received power communicates with a detection device such as a gas meter, a gas sensor, or a fire alarm, for example, and has received meter reading information indicating a gas meter reading result, alarm information that reports the occurrence of a gas leak, fire, or the like from the detection device. In this case, meter reading information, alarm information, and the like are transmitted to a server such as a gas company or a security company via the power supply device.

In the POE technology, the output voltage of the power supply device is defined as 44V to 57V, and the input voltage to the communication device is defined as 36V to 57V. The capacitor of the power receiving circuit included in the communication device has energy proportional to the square of the input voltage. Stored. That is, assuming that the capacitance C of the capacitor and the voltage value V applied to the capacitor, an energy amount Q shown in the following equation (1) is stored in the capacitor.
Q = (1/2) CV ² (1)

  Generally, a power supply device detects whether or not an Ethernet cable is connected between itself and a communication device, and when it detects that it is connected, it performs power supply to the communication device and is connected. When it is detected that there is no connection (for example, the Ethernet cable is disconnected), the power supply is stopped.

  In the power supply device and the communication device disclosed in Patent Literature 1, the power supply device on the power supply side transmits a response request signal to the communication device on the power reception side, and the communication device that receives the response request signal transmits to the communication device. A response signal is transmitted, and power is supplied to the communication device after the power supply device confirms reception of the response signal. For this reason, when the communication apparatus is not connected to the power supply apparatus or when an apparatus that should not be supplied with power is connected, the power supply apparatus is prevented from being erroneously supplied with power.

By the way, the communication device steps down the power received by the power receiving circuit with the power supply circuit and then supplies power to the internal circuit. For example, if the power supply circuit is shorted due to a component failure and an overcurrent occurs, the overcurrent of the power supply circuit The detection unit detects an overcurrent, the safety circuit is activated, and power supply from the power supply circuit to the internal circuit of the communication device is stopped.
JP 2006-94013 A

However, even if the power supply from the power supply circuit to the internal circuit is stopped, the power supply of the power supply apparatus does not stop, so that the capacitor of the power reception circuit remains charged. In this state, if the power receiving circuit is short-circuited due to dust adhesion, dew condensation, or the like, a spark may be generated by the energy stored in the capacitor. In general, the connector pitch of the connector terminal connected to the power receiving circuit is about 1 mm. If the power supply to the internal circuit is stopped and the power supply device continues to receive power, the connector terminal is not covered. Sparks can occur.
When a spark occurs as described above, it is very dangerous if a gas leak occurs.

In addition, for example, in the event of a fire, a short circuit may occur if power is still supplied to the Ethernet cable and the communication device.
However, the conventional general power supply apparatus is not configured to stop power supply to the communication apparatus even if an abnormality such as gas leakage or fire occurs outside the communication apparatus.
Furthermore, if power is continuously supplied from the power supply device when an overcurrent occurs, the communication device may cause abnormal heat generation.

  By the way, the power supply apparatus performs classification to check power consumption required by the communication apparatus. For this purpose, the power supply device outputs a voltage in the range of 15.5 V to 20.5 V to the communication device, detects a current value output to the communication device corresponding to the output voltage value, and based on the detection result The four classes are classified, and power corresponding to the classified classes is output to the communication device. The four classes are class 0 (0.44 W to 12.95 W), class 1 (0.44 W to 3.84 W), class 2 (3.84 W to 6.49 W), and class 3 (6.49 W to 12). .95W). The power consumption of a general communication device is about 1 W, and is classified into class 1. For this reason, when the electric power output from the power supply apparatus exceeds 3.84 W due to the occurrence of an overcurrent in the communication apparatus, the power supply apparatus detects an abnormality and stops power supply to the communication apparatus.

  However, until the power output from the power supply apparatus exceeds 3.84 W, power supply from the power supply apparatus to the communication apparatus is continued even if an overcurrent is generated inside the communication apparatus. In addition, when the power supply device or the communication device does not support the classification, even if an overcurrent is generated inside the communication device, the power output from the power supply device is the maximum supply capacity (12.95 W) of the power supply device. The power supply from the power supply device to the communication device is continued until it exceeds. For this reason, not only a configuration in which the power supply device detects an overcurrent of the communication device to stop power supply but also a mechanism in which the communication device detects its own overcurrent and actively stops power supply of the power supply device is required. ing.

  On the other hand, as disclosed in Patent Document 1, in the method of stopping power feeding when the power feeding device cannot receive a response signal from the communication device, the power feeding device actively communicates with the communication device in order to confirm whether the power feeding is continued. The power feeding device needs to have a function of performing communication, but such a function is not provided in a general power feeding device.

  The present invention has been made in view of such circumstances, and its main purpose is to reduce the input current value of the power receiving circuit and / or increase the input impedance of the power receiving circuit when it is determined that the power receiving is to be stopped. By adopting the configuration, it is an object of the present invention to provide a communication device that can stop the power feeding of the power feeding device for safety when an abnormality occurs without using a special power feeding device.

  Another object of the present invention is to stop receiving power when alarm information reporting danger or abnormality is received, so that when an abnormality occurs outside the device, the power supply of the power supply device is stopped for safety. An object of the present invention is to provide a communication device that can be made to operate.

  Another object of the present invention is to stop power feeding when an abnormality occurs inside or outside the device, for safety, by stopping power reception when communication with the outside is interrupted. It is to provide a communication device that can be used.

  Another object of the present invention is to make it possible to stop the power feeding of the power feeding device for safety when an abnormality occurs inside the device by adopting a configuration that stops power reception when an overcurrent is detected. To provide an apparatus.

  Another object of the present invention is to provide a communication device that can transmit the occurrence of an abnormality to another device by notifying information related to the stop of power reception before stopping power reception. .

  Still another object of the present invention is to provide a configuration in which a low-voltage battery is used as a power source after the power reception is stopped to continuously notify information related to the power reception stop, thereby improving the safety and preventing the occurrence of an abnormality. Another object of the present invention is to provide a communication device that can continuously transmit data to the device.

  The communication device according to the present invention communicates via a power receiving circuit that receives power from outside via a communication power line, first communication means for communicating via the communication power line, and a communication line other than the communication power line. In the communication device comprising the second communication means, the stop determination means for determining whether or not to stop the power reception, and when the stop determination means determines that the power reception is stopped, the power supply side of the power reception circuit A reduction means for decreasing the input current value and / or an increase means for increasing the input impedance from the power feeding side of the power receiving circuit are provided.

  The communication device according to the present invention is characterized in that the stop determination means determines that the power reception is stopped when alarm information reporting a danger or abnormality is received via the second communication means. To do.

  The communication apparatus according to the present invention is characterized in that the stop determination means determines that the power reception is stopped when communication via the first communication means or the second communication means is interrupted.

  The communication apparatus according to the present invention includes detection means for detecting that an overcurrent has flowed therein, and the stop determination means determines that power reception is stopped when the detection means detects an overcurrent. It is characterized by being.

  In the communication device according to the present invention, when the stop determination unit determines to stop the power reception, the power reception is stopped before the decrease of the input current value by the decrease unit and / or the increase of the input impedance by the increase unit is performed. It is characterized by comprising pre-execution notification means for transmitting notification information for notifying information related to the information via the first communication means.

  The communication device according to the present invention includes a battery charged with a voltage obtained by stepping down a voltage received by the power receiving circuit, and after execution of a decrease in input current value by the decrease unit and / or an increase in input impedance by the increase unit. And post-execution notification means for repeatedly transmitting, via the first communication means, notification information for notifying information related to the stoppage of power reception using the power charged in the battery.

In the present invention, when the stop determination unit determines whether or not to stop power reception and determines to stop power reception, at least one of the decrease unit and the increase unit operates.
The reducing means reduces the input current value from the power feeding side of the power receiving circuit to be less than a predetermined current value. Further, the increasing means increases the input impedance from the power supply side of the power receiving circuit beyond a predetermined impedance. In order to decrease the input current value and increase the input impedance, for example, the power receiving circuit is disconnected from the power feeding side.

Here, when the communication power line is disconnected on the communication device side and / or the power supply device side that supplies power to the communication device, the input current value becomes less than the predetermined current value, and the input impedance becomes equal to or higher than the predetermined impedance.
A general power supply device detects whether an input current value for a power receiving circuit is equal to or higher than a predetermined current value and / or whether an input impedance for the power receiving circuit is equal to or lower than a predetermined impedance. When it is detected that the value is less than the predetermined current value and / or the input impedance exceeds the predetermined impedance, the power supply to the communication device is stopped.
For this reason, when one or both of the decrease means and the increase means operate, the power supply of the power supply apparatus is stopped, and the power reception of the power reception circuit is stopped.

  The communication device operates with the power received by the power receiving circuit from the outside via the communication power line, communicates via the first communication means and the communication power line, and via the communication line other than the second communication means and the communication power line. connect.

  In the present invention, when alarm information reporting danger or abnormality is received via the second communication means, the stop determination means determines that power reception is stopped, and at least one of the decrease means and the increase means Operate. That is, when alarm information is received from the outside, the power feeding of the power feeding device is stopped, and the power receiving circuit is stopped.

  In the present invention, for example, when a signal that is constantly or periodically transmitted from the outside is not received, or when a response signal corresponding to a response request signal transmitted to the outside is not received, etc. In addition, when communication via the first communication means is interrupted or when communication via the second communication means is interrupted, it is determined that the stop determination means stops power reception, and at least one of the decrease means and the increase means operates. To do. That is, when communication with the outside is interrupted, the power feeding of the power feeding device is stopped, and the power receiving circuit is stopped.

  In the present invention, the detection means detects that an overcurrent has flowed inside the communication device, and when the overcurrent is detected, the stop determination means determines that the power reception is stopped, and the reduction means and At least one of the increasing means is activated. That is, when an overcurrent flows inside the communication device, the power feeding of the power feeding device stops, and the power receiving circuit stops receiving power.

  In the present invention, when the stop determination unit determines to stop the power reception, before the operation of the decrease unit and / or the increase unit, the pre-execution notification unit notifies the information about the stop of the power reception, Transmit via the first communication means. Before the reduction means and / or the increase means are operated, the power receiving circuit can communicate via the first communication means and the communication power line using the power received from the outside via the communication power line. Before the communication is disabled due to the stop, the notification information is transmitted to the outside.

In the present invention, when the stop determination means determines that the power reception is stopped, the post-execution notification means uses the power charged in the battery after the operation of the decrease means and / or the increase means. Broadcast information for broadcasting information about the stop is repeatedly transmitted via the first communication means. After the reduction means and / or the increase means are activated, it is impossible for the power receiving circuit to use the power received from the outside via the communication power line, but the first communication means and the communication power line can be obtained by using the battery power. Thus, communication information can be transmitted to the outside without being disabled even when power reception is stopped.
In addition, since the battery is charged with a voltage obtained by stepping down the voltage received by the power receiving circuit, the battery has a sufficiently safe low voltage value.

  In the case of the communication device according to the present invention, when it is determined that the power reception is to be stopped, the power supply device can be made to recognize that the communication power line has been detached, and thus the power supply of the power supply device can be stopped. As a result, unnecessary power reception by the communication device can be stopped and occurrence of short circuit, sparks, abnormal heat generation, and the like can be suppressed.

  In the case of the communication device according to the present invention, power supply of the power supply device can be stopped when alarm information reporting danger or abnormality is received. For this reason, even when an abnormality occurs outside the communication device such as a fire or a gas leak, power reception of the communication device can be stopped, and safety can be improved.

  According to the communication device of the present invention, when the communication with the outside is interrupted, the power supply of the power supply device can be stopped. For this reason, even when an abnormality occurs inside or outside the communication device, such as a failure of the power supply device, a failure of the detection device, a failure of the first communication means or the second communication means, the power reception of the communication device can be stopped, and safety can be improved. Can be improved.

  According to the communication device of the present invention, power supply of the power supply device can be stopped when an overcurrent flows inside the communication device. For this reason, even when an abnormality occurs inside the communication device, such as a failure of a component included in the communication device or a short circuit, power reception of the communication device can be stopped, and safety can be improved.

  In the case of the communication apparatus according to the present invention, before communication becomes impossible due to power reception stop, for example, notification information to be notified to the administrator of the communication apparatus can be transmitted to the central apparatus communicating with the communication apparatus. For this reason, the administrator can quickly cope with the occurrence of an abnormality, and the safety can be further improved.

  In the case of the communication device according to the present invention, the power of the battery is used, for example, informing information to be notified to the administrator of the communication device to the central device that communicates with the communication device without being disabled after power reception is stopped. Can be sent. For this reason, the administrator can quickly cope with the occurrence of an abnormality, and the safety can be further improved.

Also, since the notification information is repeatedly transmitted, for example, even if a temporary failure occurs in the power supply device having the communication relay function, the notification information is transmitted to the central device when the communication relay function of the power supply device is recovered. Therefore, the notification information can be reliably transmitted to the target to be notified.
Further, since the battery operates at a low voltage, it is possible to suppress the occurrence of sparks, abnormal heat generation, and the like caused by the battery power.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

Embodiment 1.
FIG. 1 is a block diagram showing a schematic configuration of a communication system including a communication apparatus according to Embodiment 1 of the present invention.
In the figure, reference numeral 2 denotes a communication device. The communication device 2 is connected to a detection device 11 such as a gas meter, a gas sensor, or a fire alarm through a communication line 10 and communicates with each other. The communication device 2 and the detection device 11 may be connected wirelessly.

The communication device 2 has an IP address and is connected to a router 3 which is a communication relay device and a power supply device via a communication power line 4 using an Ethernet cable.
Further, the router 3 is connected to the central apparatus 12 via a network 13 such as a LAN, WAN, or the Internet.

The communication device 2 is a terminal device for the central device 12 and operates by receiving power supply from the router 3 by the POE via the communication power line 4.
In such a communication system, meter reading information indicating the result of gas meter reading, alarm information for notifying that a fire has occurred, reporting that a gas leak has occurred, and that gas has been shut off in response to the occurrence of a gas leak Alarm information to be transmitted is transmitted from the detection device 11 to the communication device 2.

Further, the communication device 2 and the central device 12 communicate with each other according to a predetermined protocol such as TCP / IP, and are relayed to the router 3 to receive meter reading information, notification information including alarm information as described later, and the like. It is transmitted from the communication device 2 to the central device 12.
The central device 12 notifies the received meter reading information, notification information, etc. to the administrator of the central device 12, for example, and the notified administrator notifies the gas user of the fee according to the meter reading information. Deal with gas leaks and fires.

FIG. 2 is a block diagram illustrating a schematic configuration of the communication apparatus according to Embodiment 1 of the present invention, and FIG. 2 includes a block diagram illustrating a schematic configuration of the router 3. FIG. 3 is a circuit diagram illustrating a schematic configuration of a power receiving circuit included in the communication device.
First, the configuration of the communication device 2 will be described.
The communication device 2 includes a connector (first communication means) 20 using an RJ45 connector, an Ethernet transceiver unit 21 connected to the connector 20, and a MAC (Media Access Control) unit 22 connected to the Ethernet transceiver unit 21. The communication power line 4 is connected to the connector 20.

  The Ethernet transceiver unit 21 converts the signal, information, and the like processed by the MAC unit 22 into an Ethernet signal, and performs transmission to the router 3 via the communication power line 4 connected to the connector 20. The Ethernet transceiver unit 21 converts an Ethernet signal received via the communication power line 4 into a signal, information, or the like that can be processed by the MAC unit 22.

  Further, the communication device 2 includes a control unit 23 using a microprocessor as a control center of the communication device 2 itself, and further an interface (second communication means) for the communication device 2 to communicate with the detection device 11. 24, and the communication line 10 is connected to the interface 24.

  The control unit 23 is connected to each of the MAC unit 22 and the interface 24, and outputs a signal, information, or the like input from the MAC unit 22 (or interface 24) side to the interface 24 (or MAC unit 22) side. Then, predetermined protocol conversion is performed. For this reason, the communication between the detection device 11 and the central device 12 having different protocols is possible via the communication device 2.

  Here, a link pulse for establishing a mutual link is always transmitted from the Ethernet transceiver unit 21 to the router 3. Similarly, when the link pulse is always transmitted from the router 3 to the Ethernet transceiver unit 21 and the Ethernet transceiver unit 21 receives the link pulse, the control unit 23 determines that the link to the router 3 is established. If the link pulse is not received, it is determined that the link to the router 3 is not established.

Furthermore, the communication device 2 includes a power receiving circuit 25 connected to the connector 20, a power circuit 26 connected to the power receiving circuit 25, and a battery 27 connected to the power circuit 26.
The power receiving circuit 25 receives power supplied via an empty line or a data line of the communication power line 4. The power receiving circuit 25 includes switches SW1 and SW2 each using an FET (see FIG. 3). The control unit 23 outputs a stop signal for turning off the switches SW1 and SW2 to the power receiving circuit 25 when power reception is stopped.

The power supply circuit 26 converts the power received by the power receiving circuit 25 into a voltage value necessary for the communication device 2 and supplies power to each part of the device including the battery 27. The power supply circuit 26 normally supplies the power supplied from the router 3 to each part of the device. When the power supply from the router 3 stops, the power supply circuit 26 supplies the power supplied from the battery 27 to each part of the device.
Further, the power supply circuit 26 includes a comparison unit 28. The comparison unit 28 detects an overcurrent using a resistor and a comparator that detects that the voltage drop caused by the resistor is equal to or greater than a predetermined value. A detection signal indicating that an overcurrent has been detected is output to the control unit 23. That is, the comparison unit 28 functions as a detection unit.
The detection signal output from the comparison unit 28 is also input to the power receiving circuit 25.

Each of the switches SW1 and SW2 is configured to be turned off when a stop signal is input from the control unit 23 or a detection signal is input from the comparison unit 28.
By the way, when operating by the battery 27, in order to prevent the battery 27 from being consumed, the control unit 23 controls each part of the apparatus so as to operate in the low power consumption mode. Etc., or only when a predetermined time has elapsed from a predetermined time point, the communication with the central device 12 is performed. The elapsed time may be measured using a timer (not shown) or by counting the number of clocks.

Next, a more detailed configuration of the power receiving circuit 25 will be described.
As shown in FIG. 3, the power receiving circuit 25 includes an input capacitor Cin for the input terminals IN + and IN− connected to the connector 20, and for the output terminals OUT + and OUT− connected to the power supply circuit 26. And an output capacitor Cout, and an authentication resistor Rdet for indicating that the communication device 2 is a POE-compatible device is provided between the input capacitor Cin and the output capacitor Cout. In parallel.
Here, the resistance value of the resistor Rdet is 25 kΩ, the capacitance of the input capacitor Cin is smaller than the capacitance of the output capacitor Cout, and each capacitance is set to a predetermined value based on the regulations of the POE technology. ing.

  The switch SW1 is arranged in series with the resistor Rdet, and the switch SW2 is arranged between the switch SW1, the resistor Rdet, and the output capacitor Cout. For this reason, the router 3 and the input capacitor Cin are connected via the communication power line 4 regardless of whether the switches SW1 and SW2 are turned on or off, and the router 3 is connected via the communication power line 4 when the switch SW1 is turned on. And the resistor Rdet are connected, and the input capacitor Cin and the output capacitor Cout are connected by turning on the switch SW2.

  The switch SW1 is normally turned on, and the switch SW2 is turned off before power is supplied from the router 3. The switch SW2 that is turned off is turned on by a switch control circuit (not shown) provided in the power receiving circuit 25 when the voltage value between the input terminals IN + and IN− becomes equal to or higher than a predetermined voltage value.

  When the control unit 23 sequentially or simultaneously executes a first abnormality detection process shown in FIG. 6 and a second abnormality detection process shown in FIG. 7 described later, By executing the stop process, a stop signal is output to the power receiving circuit 25 to turn off both the switches SW1 and SW2.

Finally, the configuration of the router 3 will be described.
As shown in FIG. 2, the router 3 includes a connector 30 using an RJ45 connector, an Ethernet transceiver unit 31 connected to the connector 30, and a MAC unit 32 connected to the Ethernet transceiver unit 31. Each of the connector 30, the Ethernet transceiver unit 31, and the MAC unit 32 corresponds to the connector 20, the Ethernet transceiver unit 21, and the MAC unit 22 of the communication device.

  The router 3 further includes a power feeding circuit 33 connected to the connector 30. The power feeding circuit 33 is a 25 kΩ resistor (this embodiment) provided in a power receiving circuit of an electrical device connected via the communication power line 4. In the embodiment, when the resistor Rdet) of the communication device 2 is detected, power supply is performed via an empty line or a data line of the communication power line 4. Details of the detection procedure of the resistor Rdet will be described later.

  In such a router 3, whether or not the input current value (DC current value) to the power receiving circuit 25 is greater than or equal to a predetermined current value (specifically, 10 mA) based on the voltage value and current value output from the power feeding circuit 33. And whether or not the input impedance (AC impedance) to the power receiving circuit 25 is equal to or lower than a predetermined impedance (specifically 26.25 kΩ).

  When the input current value is equal to or higher than the predetermined current value and the input impedance is equal to or lower than the predetermined impedance, the router 3 recognizes that the communication power line 4 is connected and the power supply circuit 33 supplies power. . On the other hand, when the input current value is less than the predetermined current value or the input impedance exceeds the predetermined impedance, the router 3 recognizes that the communication power line 4 has been disconnected, and prevents the router 3 from being overheated or short-circuited. Therefore, the power feeding circuit 33 is configured to stop power feeding.

FIG. 4 is a characteristic diagram illustrating a change over time of a voltage value input to the power receiving circuit included in the communication device according to Embodiment 1 of the present invention, where the horizontal axis indicates the elapsed time and the vertical axis indicates the voltage value. This voltage value is a voltage value applied between the input terminals IN + and IN− of the power receiving circuit 25 of the communication device 2 and corresponds to the voltage value output by the power feeding circuit 33 of the router 3.
FIG. 5 is a characteristic diagram showing the time change of the voltage value output from the power receiving circuit included in the communication apparatus, where the horizontal axis indicates the elapsed time and the vertical axis indicates the voltage value. This voltage value is a voltage value applied between the output terminals OUT + and OUT− of the power receiving circuit 25 of the communication device 2.

In order to detect the resistor Rdet, the power feeding circuit 33 changes the voltage in the range of 2.8V to 10V in two steps and outputs the voltage to the communication device 2, and outputs the voltage to the communication device 2 corresponding to the voltage value of each step. The output current value is detected, and the presence or absence of the resistor Rdet is determined based on the detected current value. As a result, as shown in FIG. 4, a voltage that changes largely in two stages is applied between the input terminals IN + and IN− from the timing T ₁ to the timing T ₂ .
Specifically, the resistance value R = (V ₂ −V ₁ ) calculated based on the current value I ₁ when the voltage value V ₁ is applied and the current value I ₂ when the voltage value V ₂ is applied. When / (I ₂ −I ₁ ) is within a predetermined range, it is determined that the resistor Rdet is present.

When the presence of the resistor Rdet is detected, the power feeding circuit 33 outputs a voltage of 36V to 57V.
At this time, the power supplied from the power feeding circuit 33 via the input terminals IN + and IN− is charged to the input capacitor Cin. As a result, the voltage value between the input terminals IN + and IN− gradually increases after the timing T ₃ and becomes a substantially constant value after the input capacitor Cin is fully charged.

Then, the input terminal IN +, the voltage value between IN- is (in this embodiment 36V) predetermined voltage value is the switch SW2 is turned on at the timing T ₄ goes over to the output capacitor Cout side from the input capacitor Cin side Power is supplied and the output capacitor Cout is charged. As a result, as shown in FIG. 5, the voltage value between the output terminals OUT + and OUT− gradually increases after the timing T ₄ and becomes substantially constant after the output capacitor Cout is fully charged. Power is supplied from the power receiving circuit 25 to the power supply circuit 26 via the output terminals OUT + and OUT−.

When the control unit 23 outputs a stop signal to the power receiving circuit 25 at timing T ₅ , or when the comparison unit 28 of the power supply circuit 26 outputs a detection signal to the power receiving circuit 25, both the switches SW 1 and SW 2 are turned off.
When the switch SW1 is turned off, the connection between the router 3 and the resistor Rdet is cut off. In other words, the power feeding circuit 33 and the resistor Rdet are disconnected.

  Further, when the switch SW2 is turned off, the connection between the input capacitor Cin (and the router 3) and the output capacitor Cout is cut off. In other words, the power feeding circuit 33 and the power supply circuit 26 are disconnected. For this reason, even if the power supply from the power supply circuit 33 is continued, the supplied power is not supplied to each part of the communication device 2 by the power supply circuit 26.

When the switches SW1 and SW2 are turned off, no current flows except for the input capacitor Cin. That is, the input current value from the power supply side of the power receiving circuit 25 is reduced to less than a predetermined current value. As a result, since the input current value of the power receiving circuit 25 detected by the router 3 becomes less than the predetermined current value, the power feeding of the power feeding circuit 33 is stopped.
That is, the switches SW1 and SW2 function as a decrease unit by being turned off in response to an input of a stop signal or a detection signal.

  If one of the switches SW1 and SW2 remains on, the current continues to flow through the power receiving circuit 25, so that the input current value does not become less than the predetermined current value, and the input capacitor Cin and / or the output capacitor Cout is input. Since the impedance is set to be equal to or lower than the predetermined value, the router 3 cannot recognize that the communication power line 4 has been dropped, and power feeding is continued.

After feeding of the feeder circuit 33 is stopped, the input capacitor Cin begins to self-discharge the input capacitor Cin until the amount of charge is substantially "0", as shown in FIG. 4, the timing T ₅ or later, the input terminal IN + , IN− gradually decreases and finally becomes approximately 0V. Here, since the capacitance of the input capacitor Cin is smaller than the capacitance of the output capacitor Cout, the accumulated charge amount is small and the risk is low.
Even when the power supply of the power supply circuit 33 is stopped, the power supply from the output capacitor Cout to the power supply circuit 26 is performed until the amount of charge of the output capacitor Cout becomes substantially “0”. Therefore, as shown in FIG. T ₅ and later, the output terminal OUT +, the voltage value between OUT- is gradually lowered, eventually becomes substantially 0V.

  Here, the reason why the switches SW1 and SW2 are turned off not only by the stop signal but also by the detection signal is that a failure occurs in the communication device 2 due to an overcurrent generated in the power supply circuit 26, and the control is performed. This is because even when the unit 23 cannot output the stop signal, the switches SW1 and SW2 can be turned off. For this reason, the safety of the communication device 2 is further improved.

Between the timing T ₂ and timing T ₃ shown in FIG. 4, classification of assigning the power supply capacity of the power supply circuit 33 according to the power consumption of the communication device 2 may be performed.

  In this way, by stopping both the power feeding from the power feeding circuit 33 to the power receiving circuit 25 and the power feeding from the power receiving circuit 25 to the power supply circuit 26, the router 3, the communication power line 4, and the communication device 2 have a high voltage. As a result, for example, when a failure occurs in each part in the router 3 or the communication device 2 or when a short circuit of the communication power line 4 occurs, safety is improved.

FIG. 6 is a flowchart showing a procedure of first abnormality detection processing executed by the control unit of the communication apparatus according to Embodiment 1 of the present invention.
First, the control unit 23 substitutes “0” for the variable A indicating the type of abnormality (S11).
Next, the control unit 23 determines whether or not information has been received from the detection device 11 (S12), and if received (YES in S12), determines whether or not the received information is alarm information ( S13) If it is alarm information (YES in S13), "1" meaning occurrence of fire, gas leakage, etc. is substituted for variable A (S14), and a subroutine for performing power reception stop processing (see FIG. 8) Is called and executed (S15).

By executing the power reception stop process in S15, the power supply to the router 3 is stopped, and the occurrence of an abnormality is notified. As a result, the energy accumulated in the input capacitor Cin and / or the output capacitor Cout due to continuation of the power supply generates a spark to reduce the risk of igniting the leaked gas, and the risk of a power short circuit due to a fire. Is reduced.
After the process of S15 is completed, the control unit 23 ends the first abnormality detection process.

  When the information received in S12 is not alarm information but, for example, meter reading information (NO in S13), the control unit 23 transmits the received information to the central device 12 (S16), and returns the process to S11.

When information is not received from the detection device 11 (NO in S12), the control unit 23 determines whether or not a detection signal is input from the comparison unit 28 (S17), and when it is input (YES in S17). ), Substituting “2”, which means the occurrence of overcurrent, for the variable A (S18), the process proceeds to S15, and a subroutine for performing a power reception stop process is called and executed. At this time, power supply to the router 3 is stopped, and the occurrence of an abnormality is notified.
However, when some trouble occurs and, for example, the processing after S18 is not executed, the notification of the occurrence of the abnormality is not executed, but the power supply of the router 3 is stopped at a minimum. For this reason, it is suppressed that the communication apparatus 2 generates heat abnormally due to generation of overcurrent and continuation of power reception.

  When the detection signal is not input from the comparison unit 28 (NO in S17), the control unit 23 determines whether or not the Ethernet transceiver unit 21 has received the link pulse (S19), and if not received (S19). NO), substituting “3”, which means that the link to the router 3 is not established (that is, communication from the router 3 is interrupted) into the variable A (S20), moves the process to S15, and stops receiving power. Calls and executes a subroutine for processing. At this time, power supply to the router 3 is stopped, and the occurrence of an abnormality is notified.

  The case where the link to the router 3 is not established may be, for example, a case where the Ethernet transceiver unit 21 has failed or a case where the router 3 has failed. However, since power supply to the router 3 is stopped, abnormal heat generation due to the failure of the Ethernet transceiver unit 21 is avoided, and the risk that an abnormal voltage is applied from the failed router 3 is reduced.

  When the Ethernet transceiver unit 21 receives the link pulse (YES in S19), the link to the router 3 has been established, and no fire, gas leakage, or the like has occurred outside the communication device 2, and the communication device 2 has an internal structure. Since no overcurrent has occurred, the control unit 23 returns the process to S11.

  Regarding the first abnormality detection process as described above, the control unit 23 in S13 determines whether the received information is alarm information, that is, alarm information reporting a danger or abnormality via the second communication means. It functions as a stop determination means for determining whether or not to stop power reception based on whether or not it has been received. Further, the control unit 23 in S17 determines whether or not to stop the power reception based on whether or not the detection signal is input from the comparison unit 28, that is, based on whether or not the detection unit detects an overcurrent. It functions as a stop determination means. Further, whether the control unit 23 in S19 stops the power reception based on whether the Ethernet transceiver unit 21 has received the link pulse, that is, based on whether the communication via the first communication means is interrupted. It functions as a stop determination means for determining whether or not.

FIG. 7 is a flowchart showing a procedure of second abnormality detection processing executed by the control unit of the communication apparatus according to Embodiment 1 of the present invention.
The control unit 23 transmits a response request signal to the detection device 11 (S31), and starts counting elapsed time (S32). The detection device 11 that has received the response request signal transmits a response signal to the communication device 2.
Next, the control unit 23 determines whether or not a response signal from the detection device 11 has been received (S33). If the response signal has not yet been received (NO in S33), a predetermined standby time has elapsed. If it has not elapsed (NO in S34), the process returns to S33.

When the response signal from the detection device 11 is received (YES in S33), the time counting from S32 is terminated (S35), and the process returns to S31. Here, an appropriate interval may be set before the execution of the next processing of S31.
When the elapsed time from the processing execution time of S32 has passed the predetermined standby time (YES in S34), the time measurement is terminated (S36), and “4” which means that communication from the detection device 11 is interrupted is a variable. Substituting into A (S37), a subroutine for performing a power reception stop process is called and executed (S38).
By executing the power reception stop process in S38, the power supply of the router 3 is stopped, and the occurrence of an abnormality is notified.
After the process of S38 is completed, the control unit 23 ends the second abnormality detection process.

  The case where the communication from the detection device 11 is interrupted may be, for example, the case where the detection device 11 breaks down. However, since power supply to the router 3 stops, useless communication from the communication device 2 to the failed detection device 11 is not performed. Further, even when the occurrence of gas leakage, fire, or the like cannot be detected due to the failure of the detection device 11, the energy accumulated in the input capacitor Cin and / or the output capacitor Cout due to continuation of power supply generates a spark, The risk of igniting the leaked gas is reduced, and the risk of a power supply short circuit due to a fire is reduced.

  Regarding the second abnormality detection process as described above, the control unit 23 in S33 determines whether or not the communication via the second communication means has been interrupted based on whether or not the response signal from the detection device 11 has been received. Based on this, it functions as a stop determination means for determining whether to stop power reception.

FIG. 8 is a flowchart showing a subroutine of the power reception stop processing procedure executed by the control unit of the communication apparatus according to Embodiment 1 of the present invention.
The control unit 23 refers to the value assigned to the variable A, and generates notification information for reporting information related to the stop of power reception (S51). Specifically, in S51, when A = 1, notification information including the alarm information received in S13 and notifying that power reception from the router 3 is stopped is generated, and A = 2 Includes information indicating that an overcurrent has occurred, and notification information for notifying that power reception from the router 3 is to be stopped is generated. In addition, when A = 3 (or A = 4), information indicating that the communication from the router 3 (or the detection device 11) has been interrupted is included to notify that the power reception from the router 3 is to be stopped. Broadcast information is generated.

  Next, the control unit 23 transmits the notification information generated in S51 to the central device 12 (S52), and outputs a stop signal to the power receiving circuit 25 (S53). By executing the process of S53, each of the switches SW1 and SW2 is turned off, the power supply from the router 3 to the power receiving circuit 25 is stopped, and the power supply from the power receiving circuit 25 to the power supply circuit 26 is stopped. In addition, power supply from the battery 27 to the power supply circuit 26 is automatically started, and the communication device 2 operates with the power of the battery 27.

After the processing of S53 is completed, the control unit 23 shifts to the low power consumption mode (S54), and reduces the total amount of power consumed by each unit of the communication device 2 including the control unit 23. For this reason, the power of the battery 27 lasts for a long time.
Furthermore, the control unit 23 starts counting elapsed time (S55), determines whether or not a predetermined time has elapsed (S56), and if not (NO in S56), performs the process of S56. repeat.

When the elapsed time from the process execution time of S55 has passed the predetermined time (YES in S56), the control unit 23 ends the time measurement (S57), and transmits the notification information generated in S51 to the central device 12 (S58). Then, it is determined whether or not to terminate the notification (S59).
When it determines with not complete | finishing alerting | reporting (it is NO at S59), the control part 23 returns a process to S55. As described above, by repeating the processing of S55 to S59, the notification information is repeatedly transmitted from the communication device 2 to the central device 12 regardless of whether or not the router 3 is in a state of being able to relay the notification information from the communication device 2. Sent. For this reason, possibility that the central apparatus 12 will receive alerting | reporting information becomes high, and safety | security is improved.

Here, the condition for terminating the notification in S59 is, for example, when the process of S58 is executed a predetermined number of times or when the charge amount of the battery 27 is excessively reduced.
When it determines with complete | finishing alerting | reporting (it is YES at S59), the control part 23 complete | finishes a power reception stop process.

The control unit 23 in S52 of such a power reception stop process functions as a pre-execution notification unit, and the control unit 23 in S58 functions as a post-execution notification unit.
For example, when alarm information is received from the detection device 11 while the processes of S55 to S59 are repeated, the notification information including the received alarm information is regenerated, and the regenerated notification information is repeatedly notified. It is desirable to have a configuration. Further, the power receiving stop process may be forcibly terminated by repeating the processes of S55 to S58 without performing the process of S59, for example, by pressing a reset button (not shown).

  The communication device 2 as described above causes the router 3 to recognize that the communication power line 4 has been detached when an abnormality occurs inside or outside the communication device 2, and stops power feeding. In addition, the communication device 2 notifies the central device 12 of the occurrence of abnormality before the power reception by the POE is stopped, and further, after the power reception is stopped, the communication device 2 operates with the low-voltage battery 27 and causes the abnormality to occur in the central device 12. Inform. For this reason, short-circuiting, abnormal heat generation, ignition of gas due to occurrence of sparks, and the like are suppressed to improve safety, and further, early recovery is possible by repairing a failure, dealing with a disaster, and the like.

In addition, since the switches corresponding to the switches SW1 and SW2 are arranged in the power receiving circuit included in the conventional communication apparatus, the switches are changed so that the switches can be turned off from the control unit 23 and the comparison unit 28, respectively. As a result, the communication device 2 of the present invention is simply configured.
The communication device 2 may be configured to communicate with a plurality of detection devices 11, 11,.

Embodiment 2. FIG.
FIG. 9 is a circuit diagram showing a schematic configuration of a power receiving circuit included in the communication apparatus according to Embodiment 2 of the present invention.
The communication device of the present embodiment is substantially the same as the communication device 2 of the first embodiment, but the configuration of the power receiving circuit 251 of the present embodiment is different from the configuration of the power receiving circuit 25 of the first embodiment. Specifically, the power receiving circuit 251 includes substantially the same input capacitor Cin, output capacitor Cout, input terminals IN + and IN−, output terminals OUT + and OUT−, resistors Rdet, and the like included in the power receiving circuit 25 of the first embodiment. Although the switch SW2 is provided, the switch SW1 is not provided, but the switch SW3 is provided instead.

  The switch SW3 is disposed between the input terminals IN + and IN− and the input capacitor Cin. For this reason, when the switch SW3 is turned on, the power feeding circuit 33 and the power receiving circuit 251 are connected via the communication power line 4. Here, the switch SW3 is normally turned on similarly to the switch SW1 in the first embodiment, and the process of S53 is executed and a stop signal is input from the control unit 23 to the power receiving circuit 251, or When a detection signal is input from the comparison unit 28 to the power receiving circuit 251, the switches SW2 and SW3 are turned off.

When the switch SW3 is turned off, the power feeding circuit 33 and the power receiving circuit 251 are disconnected. At this time, no current flows through the power receiving circuit 25. That is, the input current value from the power feeding side of the power receiving circuit 25 decreases to less than a predetermined current value, and the input impedance from the power feeding side of the power receiving circuit 25 increases above the predetermined impedance. As a result, since the input current value of the power receiving circuit 25 detected by the router 3 is equal to or lower than the predetermined current value and the input impedance of the power receiving circuit 25 exceeds the predetermined impedance, the power feeding of the power feeding circuit 33 is stopped.
As described above, since both the decrease of the input current value and the increase of the input impedance are executed, the router 3 does not stop the power feeding unless both the decrease of the input current value and the increase of the input impedance are established. However, power supply is reliably stopped.

Note that if the switch SW3 is turned off, the entire power receiving circuit 251 is disconnected from the router 3 side. Therefore, the power feeding of the power feeding circuit 33 is stopped without turning off the switch SW2, but safety is improved by turning off the switch SW3. The Conversely, if the switch SW3 remains turned on even when the switch SW2 is turned off, the current continues to flow through the power receiving circuit 25, so that the input current value does not become less than the predetermined current value, and the input capacitor Cin reduces the input impedance. In order to make it equal to or less than the predetermined value, the router 3 cannot recognize that the communication power line 4 has been dropped, and power feeding continues.
That is, the switch SW3 functions as a reducing unit and an increasing unit by being turned off in response to the input of the stop signal or the detection signal.

  Other parts corresponding to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  Like the communication device 2 of the first embodiment, the communication device as described above causes the router 3 to recognize that the communication power line 4 has been disconnected when an abnormality occurs inside or outside the communication device, and stops power feeding. The central device 12 is notified of the occurrence of an abnormality. For this reason, short-circuiting, abnormal heat generation, ignition of gas due to occurrence of sparks, and the like are suppressed to improve safety, and further, early recovery is possible by repairing a failure, dealing with a disaster, and the like.

Embodiment 3. FIG.
FIG. 10 is a circuit diagram showing a schematic configuration of a power receiving circuit included in the communication apparatus according to Embodiment 3 of the present invention.
The communication device of the present embodiment is substantially the same as the communication device 2 of the first embodiment, but the configuration of the power receiving circuit 252 of the present embodiment is different from the configuration of the power receiving circuit 25 of the first embodiment. Specifically, the power reception circuit 252 includes an input capacitor Cin, an output capacitor Cout, input terminals IN + and IN−, output terminals OUT + and OUT−, and a resistor Rdet that are substantially the same as those included in the power reception circuit 25 of the first embodiment. And switches SW1 and SW2, and further includes a switch SW4.

  The switch SW4 is arranged in series with the input capacitor Cin. For this reason, when the switch SW4 is on, the power feeding circuit 33 and the input capacitor Cin are connected via the communication power line 4. Here, each of the switches SW1 and SW4 is normally turned on, and when the process of S53 is executed and a stop signal is input from the control unit 23 to the power reception circuit 252 or the power reception circuit 252 from the comparison unit 28. When a detection signal is input to the switches SW1, SW2, SW4 are turned off.

When the switches SW1, SW2, and SW4 are turned off, the power feeding circuit 33, the input capacitor Cin, the output capacitor Cout, and the resistor Rdet (that is, the entire power receiving circuit 252) are disconnected. At this time, no current flows through the power receiving circuit 25. That is, the input current value from the power feeding side of the power receiving circuit 25 decreases to less than a predetermined current value, and the input impedance from the power feeding side of the power receiving circuit 25 increases above the predetermined impedance. As a result, since the input current value of the power receiving circuit 25 detected by the router 3 is equal to or lower than the predetermined current value and the input impedance of the power receiving circuit 25 exceeds the predetermined impedance, the power feeding of the power feeding circuit 33 is stopped.
That is, the switches SW1, SW2, and SW4 function as a decrease unit and an increase unit by being turned off in response to the input of the stop signal or the detection signal.

  As described above, since both the decrease of the input current value and the increase of the input impedance are executed, the router 3 does not stop the power feeding unless both the decrease of the input current value and the increase of the input impedance are established. However, power supply is reliably stopped.

  Other parts corresponding to those of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

  Like the communication device 2 of the first embodiment, the communication device as described above causes the router 3 to recognize that the communication power line 4 has been disconnected when an abnormality occurs inside or outside the communication device, and stops power feeding. The central device 12 is notified of the occurrence of an abnormality. For this reason, short-circuiting, abnormal heat generation, ignition of gas due to occurrence of sparks, and the like are suppressed to improve safety, and further, early recovery is possible by repairing a failure, dealing with a disaster, and the like.

It is a block diagram which shows schematic structure of a communication system provided with the communication apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the communication apparatus which concerns on Embodiment 1 of this invention. It is a circuit diagram which shows schematic structure of the receiving circuit with which the communication apparatus which concerns on Embodiment 1 of this invention is provided. It is a characteristic view which shows the time change of the voltage value input into the power receiving circuit with which the communication apparatus which concerns on Embodiment 1 of this invention is provided. It is a characteristic view which shows the time change of the voltage value output from the power receiving circuit with which the communication apparatus which concerns on Embodiment 1 of this invention is provided. It is a flowchart which shows the procedure of the 1st abnormality detection process which the control part of the communication apparatus which concerns on Embodiment 1 of this invention performs. It is a flowchart which shows the procedure of the 2nd abnormality detection process which the control part of the communication apparatus which concerns on Embodiment 1 of this invention performs. It is a flowchart which shows the subroutine of the power reception stop process procedure which the control part of the communication apparatus which concerns on Embodiment 1 of this invention performs. It is a circuit diagram which shows schematic structure of the receiving circuit with which the communication apparatus which concerns on Embodiment 2 of this invention is provided. It is a circuit diagram which shows schematic structure of the receiving circuit with which the communication apparatus which concerns on Embodiment 3 of this invention is provided.

Explanation of symbols

2 Communication device 20 Connector (first communication means)
23 control unit 24 interface (second communication means)
25, 251, 252 Power receiving circuit 27 Battery 28 Comparison unit (detection means)
4 communication power line SW1, SW2, SW3, SW4 switch (decrease means, increase means)

Claims (6)

A power receiving circuit for receiving power from outside via a communication power line;
First communication means for communicating via the communication power line;
A communication device comprising: a second communication means for communicating via a communication line other than the communication power line;
Stop determination means for determining whether to stop power reception;
Decreasing means for decreasing the input current value from the power feeding side of the power receiving circuit and / or increasing means for increasing the input impedance from the power feeding side of the power receiving circuit when the stop determination means determines to stop power reception. A communication apparatus comprising:   2. The communication according to claim 1, wherein the stop determination unit is configured to determine that the power reception is stopped when alarm information reporting danger or abnormality is received via the second communication unit. apparatus.   3. The communication apparatus according to claim 1, wherein the stop determination unit determines to stop receiving power when communication via the first communication unit or the second communication unit is interrupted. 4. . Provided with a detecting means for detecting that an overcurrent has flowed inside,
The communication apparatus according to any one of claims 1 to 3, wherein the stop determination unit determines to stop receiving power when the detection unit detects an overcurrent.   When the stop determination unit determines to stop the power reception, the notification information for notifying the information about the stop of the power reception is executed before the decrease of the input current value by the decrease unit and / or the increase of the input impedance by the increase unit. The communication apparatus according to claim 1, further comprising a pre-execution notification unit that transmits the first communication unit via the first communication unit. A battery charged by a voltage obtained by stepping down a voltage received by the power receiving circuit;
After the execution of the reduction of the input current value by the reduction means and / or the increase of the input impedance by the increase means, the notification information for informing the information about the stop of the power reception using the power charged in the battery, The communication apparatus according to any one of claims 1 to 5, further comprising post-execution notification means that repeatedly transmits via the communication means.

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