JP6637287B2 - Disaster prevention monitoring system - Google Patents

Description

  The present invention relates to a disaster prevention monitoring system that detects an alarm such as a fire and issues an alarm, and in particular, relates to a disaster prevention monitoring system that performs data transmission by ring-connecting a receiving panel and a plurality of distribution panels.

  2. Description of the Related Art Conventionally, in a local area network for highly reliable communication used in a disaster prevention monitoring system, a ring network in which a plurality of nodes are connected in a ring shape is used for data transmission. In this network, a plurality of nodes are connected by a transmission path such as an optical cable or a metal cable such as a coaxial cable or a twisted pair cable. In addition, terminal devices such as a reception board and a distribution board are connected to each of the plurality of nodes.

Here, data transmission by the transmission path is controlled by a port switching unit, a network control unit, and a board control unit functioning as a network communication interface in the node, and performs data transmission by a token passing method.

  In the data transmission by the token passing method, a transmission signal from a node on a certain board is output to both the left and right transmission paths, and is input from both the left and right to the node on the farthest board in terms of time, and communication ends.

  Further, when a failure such as a disconnection occurs in a transmission path between nodes, a bus-type network configuration is formed to prevent the entire system from going down.

JP 09-186710 A

  However, in such a conventional disaster prevention monitoring system using a ring-type network, if the distance between the panels is long, the signals input from the left and right transmission lines to the farthest board will have a time delay, and the farthest board will be delayed. There is a problem that a signal cannot be completely converged on the panel, an infinite loop in which a signal fragment turns infinitely on a ring of a transmission line occurs, and a communication failure frequently occurs.

  In order to prevent such a communication failure due to the infinite loop, a bus-type network configuration may be used. However, in the bus-type network configuration, when a disconnection failure occurs, the network is divided into two, and the network is divided. There is a problem that data cannot be transmitted between networks and the whole system goes down. To prevent this, it is necessary to duplicate the bus connection with the main line and the sub line, and the network configuration becomes complicated and the cost increases. There is.

  In order to solve this problem, the applicant of the present invention has a ring connection between a receiver and a plurality of distribution boards via a transmission line, and sets one side port of the receiver to an electrically uncommunicable state. Logically form a bus-type communication path, if a failure occurs in the transmission path, determine which board has failed, and assign one port on the failed side of the board located in front of the failure location A disaster prevention monitoring system has been proposed in which a state in which communication is not possible is changed to an electrically communicable state, and a port on one side of the receiver is changed to a state in which communication is possible in an electrically communicable state to recover a disconnection failure.

  In this disaster prevention monitoring system, the transmission path is physically in a ring state by being connected between all the panels, but one port of the receiving panel is in an electrically uncommunicable state (blocking state). Thus, as a logical communication path, a so-called pseudo ring having a bus configuration in which the ring is cut off on one side of the receiving board is configured. For this reason, a signal is transmitted from a certain board to the transmission paths on both the left and right sides. In this case, the communication is terminated after being blocked on one side of the receiver, and an infinite loop in which a signal fragment turns does not occur, thereby preventing a communication failure due to the infinite loop.

  If a communication failure such as a disconnection occurs on the transmission line, one of the ports on the failure side of the board adjacent to the failure location is set to the communication disabled state, the failure location is separated, and one of the ports on the receiving board that was in the communication disabled state is disconnected. By changing to the communicable state (forwarding state) and reconfiguring a pseudo ring with a bus configuration where the ring has been broken at the point of failure, the communicable state between all boards is maintained. By creating a state in which the ring is broken somewhere, it is possible to reliably eliminate the possibility that the signal is in an infinite loop.

  However, in a disaster prevention monitoring system configured with such a pseudo ring, if a disconnection failure or the like occurs, the receiving panel must know the order of the physical ring connection between the receiving panel and a plurality of distribution panels. However, during the operation of the system, the order of the physical ring connection of the panel to the transmission line may be changed due to expansion of the panel or repair of the panel, etc. In some cases, the order of the physical ring connections of the boards that have been connected may be different.

  When an error such as a disconnection failure occurs in a state in which the receiving board does not know the physical ring connection order of the boards in this manner, which board is determined based on the logical ring connection order in which the node IDs are ascending. Even if an attempt is made to determine whether or not a disconnection failure has occurred, there is a problem in that it is not possible to determine the failure location in the physical ring connection, and it is not possible to disconnect the failure location and reconfigure the pseudo ring.

  For example, it is assumed that five distribution boards are physically connected in a ring to the receiving board, and the node IDs of the distribution boards are # 1 to # 5. At this time, the order of the logical ring connection is (# 1- # 2- # 3- # 4- # 5) with respect to the receiver, but the physical ring connection is, for example, (the receivable port of the receiver-#). 3- # 5- # 2- # 4- # 1-communication disabled port of the receiver).

  If a disconnection fault occurs in the transmission path between the distribution boards # 2 and # 4, communication between the distribution boards # 4 and # 1, which are located on the communication-disabled port side of the receiver, cannot be performed.

  Based on the inability to communicate between the # 4 and # 1 distribution boards, even if an attempt is made to determine the location of the failure from the logical ring connection order, only the individual failures of the # 4 and # 1 distribution boards are considered. Since it cannot be recognized, the location of the failure in the physical ring connection is unknown, and the failure location cannot be separated to reconfigure the pseudo ring.

  The present invention relates to a network in which the order of the logical ring connection and the order of the physical ring connection are different from each other, and grasps the order of the physical link connection based on the ID of the token that circulates the transmission path. Even in this case, an object of the present invention is to provide a disaster prevention monitoring system that prevents a communication failure due to an infinite loop of a signal and that can reliably recover a communication state in response to the communication failure.

(Disaster prevention monitoring system)
The present invention relates to a disaster prevention monitoring system that performs data transmission by ring-connecting a parent node and a plurality of child nodes via a transmission path,
By setting one of the ports of the parent node to be in an electrically uncommunicable state, a logical bus-type communication path is formed,
A token ID detection unit for detecting a token ID which is an identifier of the received token is provided for each of the ports provided for the parent node and each child node,
The parent node and the child node each transmit a signal including a different token ID,
The token ID detection unit physically detects the token ID included in the signal transmitted from the parent node and the child node on the preceding stage, and stores token ID detection information indicating which token ID is detected,
The child node sends the detected token ID detection information to the parent node,
Parent node, based on the token ID detection information transmitted from the child node, and characterized in that a connection order detector for detecting a sequence of ring connection.

When a communication failure occurs in the transmission path, the failure location is detected based on the token ID detection information in the parent node and / or the child node after the failure and the order of the physical ring connection. A control unit is provided for changing one port of the node to a state in which communication is possible electrically and recovering a communication failure.

(Disaster prevention monitoring system)
The present invention relates to a disaster prevention monitoring system that performs data transmission by ring-connecting a parent node and a plurality of child nodes via a transmission path,
By setting one of the ports of the parent node to an electrically uncommunicable state, a logical bus-type communication path is formed,
A token ID, which is an identifier of the received token, is detected in each of the ports provided in the parent node and each of the child nodes. If the same token ID is detected within a predetermined time, the token ID is stored as a valid token. Provided a token ID detection unit that determines that the token is a true valid token when the token is detected a plurality of times in succession,
In the parent node,
A connection order detection unit that detects an order of a physical ring connection of the plurality of child nodes to a parent node based on the token ID detection information including the true valid token detected by the token ID detection unit;
When a communication failure occurs in the transmission path, the failure location is detected based on the physical ring connection order and the token ID detection information detected by the token ID detection unit , the failure location is isolated, and one port of the parent node is disconnected. A control unit for changing the state to an electrically communicable state and recovering the communication failure,
Is provided .

(Detection point of node ID)
Each of the parent node and the child node has a first port and a second port having a transmission unit and a reception unit,
The first port and the second port are:
A receiving-side gate switch that is provided on the output side of the receiving unit and that switches between a receivable state and a non-receivable state when turned on and off by a control signal from the control unit,
A transmission-side gate switch that is provided on a control line that turns on and off the transmission operation of the transmission unit and that switches between a transmission-enabled state and a transmission-disabled state by being turned on and off by a control signal from the control unit,
With
A detection point by the token ID detection unit is provided between the output of the reception unit and the input of the reception-side gate switch, and the token ID can be detected in any state where each port is switched to the communication enabled state or the communication disabled state. .

(Initial setting of pseudo ring and movement of pseudo ring in case of communication failure)
As an initial setting,
The control unit of the parent node turns on the first port to set a communication enabled state and turns off the second port to set a communication disabled state,
The control unit of the child node turns on the first and second ports to set them in a communicable state,
If a communication failure occurs on the transmission line,
The control unit of the parent node transmits a port-off control signal to instruct the child node located in front of the failure point to turn off the second port on the failure side, and receives an acknowledgment signal for the port-off control signal, Turn on the second port and switch to the communication enabled state,
When receiving the port off control signal from the parent node, the control unit of the child node turns off the second port to switch to the communication disabled state, and transmits an acknowledgment signal to the parent node.

(Reconstruction of pseudo-ring due to communication failure recovery)
If the communication failure on the transmission line is resolved,
The control unit of the parent node turns off the second port to set a communication disabled state, transmits a port-on control signal that instructs the child node that has transmitted the port-off control signal to turn on the port,
The control unit of the child node that has set the second port to the communication disabled state by the port off control signal from the parent node can turn on the second port and communicate when receiving the port on control signal from the parent node. Switch to state.

(Receiver and distribution board)
A parent node is provided in a receiving board, a plurality of child nodes are provided in a plurality of distribution boards, and data transmission is performed between the receiving board and the plurality of distribution boards.

(Main port and secondary port of receiver, upstream and downstream ports of distribution board)
The first port of the parent node provided on the receiver is set as a main port (M port) on the side that constantly communicates, and the second port is set as a secondary port (S port) on the side that does not always communicate,
The first port of the child node provided in the distributor and upstream port located on the main port side of the parent node, and downlink port located the second port to the secondary port side of the parent node.

(Basic effects)
The present invention is a disaster prevention monitoring system that performs data transmission by ring-connecting a parent node and a plurality of child nodes via a transmission path, by setting one port of the parent node to an electrically uncommunicable state, Logically forms a bus-type communication path, and each of the ports provided in the parent node and each of the child nodes is provided with a token ID detection unit for detecting a token ID which is an identifier of a token received at each port. The node has a connection order detection unit that detects the order of physical ring connection of the plurality of child nodes to the parent node based on the token ID detection information detected by the token ID detection unit, and a communication failure has occurred in the transmission path. In this case, a failure is detected based on the physical ring connection order, the failure is isolated, and one port of the parent node is changed to an electrically communicable state to cause a communication failure. Because of the provision of a control unit that restores the system, the order of the physical ring connection differs from the order of the logical ring connection of the distribution board to the parent node due to the addition or repair of nodes during system operation. In this case, the parent node detects the destination ID of the token circulating in the transmission path as a token ID and sends it to the parent node. Based on the token ID detection information sent from each child node, the parent node It knows the physical ring connection order of each child node with respect to the parent node.If a communication failure such as a disconnection failure occurs, it knows the physical connection order of the child nodes. It is possible to detect whether a failure has occurred between the child nodes, change one port of the parent node that was in a communication disabled state to a communicable state (forwarding state), With the configuration, communication between all nodes is maintained, and by creating a state where the ring is broken somewhere in the transmission line, the risk of infinite loop of the signal can be reliably eliminated. And

(Effect by detecting valid token ID)
Further, the token ID detecting unit stores the same token ID as a valid token ID when detecting the same token ID within a predetermined time, and determines a true valid token ID when detecting the valid token ID plural times in succession. The node connection order detection unit detects the physical ring connection order of the multiple child nodes to the parent node based on the true valid token, so that the tokens of the existing nodes are transmitted during normal operation. However, when the network is reconfigured, a token having a token ID of # 1 to # 255 is transmitted to the transmission line, and the token ID of a non-existent node may be erroneously detected. By detecting a valid token ID and determining a true token ID based on the detection of a valid token ID in order to prevent The to prevent.

(Effect by judging the failure location)
Further, when a communication failure occurs in the transmission path, the control unit of the parent node detects a failure location based on the token ID detection information detected by the token ID detection unit, and thus causes a communication failure such as disconnection. All the token IDs cannot be detected at the ports of the nodes located on both sides of the transmission path, and therefore, a failure point can be simply and reliably set between adjacent ports of two nodes that have not detected all the token IDs. Detectable.

(Effects due to node ID detection points)
In addition, each of the parent node and the child node has a first port and a second port including a transmission unit and a reception unit, and the first port and the second port are provided on the output side of the reception unit, and the control unit A receiving gate switch that switches between a receivable state and a non-receivable state when turned on and off by a control signal from the controller, and a control line that turns on and off the transmission operation of the transmitting unit, and transmits when turned on and off by a control signal from the control unit A transmission-side gate switch for switching between an enable state and a transmission-disabled state; a detection point provided by the token ID detection unit is provided between an output of the reception unit and an input of the reception-side gate switch; Since the token ID can be detected in any state where the state is switched, even if one side port of the parent node is in a communication disabled state, the one side port in the communication disabled state is not used. Detecting any signal capable token ID, detection of the order of physical ring connection, it can be utilized to detect the failure point.

  In addition, by providing a receiving side and a transmitting side gate switch capable of switching the first port and the second port between a communicable state and a non-communicable state by on / off control by a control unit, a communication protocol such as a token passing method is provided. Independently, the port of each node can be electrically turned on and off, and by turning off one of the ports on either side of the node, the ring is logically disconnected somewhere in the communication path Pseudo ring can be easily created.

  In the following description, a network configuration in which a transmission path is physically in a ring state, but a logical communication path is a bus configuration in which one portion of the ring is cut off is called a pseudo ring. There are cases.

(Effect of initial setting of pseudo ring and movement of pseudo ring in case of communication failure)
In addition, as an initial setting, the control unit of the parent node turns on the first port to set a communicable state, and turns off the second port to set a communicable state. When the communication failure occurs in the transmission path by turning on the second port and setting the communication enabled state, the control unit of the parent node turns off the second port on the failure side to the child node located in front of the failure point. When the acknowledgment control signal corresponding to the port-off control signal is received, the second port is turned on to switch to the communicable state, and the control unit of the child node switches the port from the parent node to the port. When the off-control signal is received, the second port is turned off to switch to the communication disabled state, and the acknowledgment control signal is transmitted to the parent node. In this case, by performing control under the control of the parent node, the communication state becomes unstable compared to the case where the child node detects a communication failure on the transmission line and turns off the port. Since the convergence direction in this case is on the communicable side, a high fail-safe is realized, and the pseudo ring can be reconfigured by reliably isolating the faulty part.

(Effects of pseudo ring reconfiguration following restoration of communication failure)
Further, when the communication failure of the transmission line is resolved, the control unit of the parent node turns off the second port to set a communication disabled state, and instructs the child node that has transmitted the port off control signal to turn on the port. The control unit of the child node that has transmitted the ON control signal and has set the second port to the communication disabled state by the port OFF control signal from the parent node, receives the port ON control signal from the parent node. Since the port is turned on to switch to the communicable state, the reconfiguration of the pseudo ring to the initial settings when the communication failure on the transmission line is resolved is the same as when a communication failure on the transmission line occurs By performing the control under the control of the node, it is possible to reliably perform the reconfiguration of the same pseudo ring as the initial setting.

Explanatory drawing showing the outline of the disaster prevention monitoring system according to the present invention Block diagram showing the configuration of the network communication function provided on the receiver Explanatory diagram showing a network configuration using a pseudo ring during normal communication Explanatory diagram showing token ID detection information detected during normal communication in FIG. 3 arranged in ascending order of node IDs Explanatory diagram showing token ID detection information detected during normal communication in FIG. 3 arranged in the order of physical ring connection Explanatory diagram showing the operation procedure of pseudo ring reconfiguration when a disconnection failure occurs in the transmission line FIG. 6 is an explanatory diagram showing token ID detection information detected when a disconnection failure has occurred in the transmission line in FIG. Flow chart showing the control operation of the receiver

[Overview of disaster prevention monitoring system]
(Network ring connection)
FIG. 1 is an explanatory diagram schematically showing a disaster prevention monitoring system according to the present invention. As shown in FIG. 1, the disaster prevention monitoring system according to the present embodiment includes a receiving panel 10 functioning as a parent node and a plurality of distribution panels 12-1 to 12-5 functioning as child nodes. It has a network configuration in which the receiving board 10 and the distribution boards 12-1 to 12-5 are physically connected in a ring shape, and performs data transmission by a token passing method.

  Here, in the present embodiment, node ID = # 1 to # 5 are set in the distribution boards 12-1 to 12-5, and node ID = # 64 is set in the reception board 10. Nodes with node IDs # 6 to # 12-4 and # 65 to # 255 do not exist.

  The order of the ring connection of the distribution boards 12-1 to 12-5 with respect to the reception board 10 is not the ascending order of the node IDs # 1 to # 5. Due to the replacement of the cable or the like, a physical ring connection is formed in a random order of the distribution boards 12-3, 12-5, 12-2, 12-4, and 12-1 counterclockwise with respect to the reception board 10.

  The receiving panel 10 includes a main port 16 (hereinafter, referred to as an “M port 16”) that constantly communicates, and a secondary port 18 (hereinafter, an “S port 18”) that does not always communicate. The boards 12-1 to 12-5 include upstream ports 20-1 to 20-5 and downstream ports 22-1 to 22-5.

  The M port 16 and S port 18 of the receiver 10 and the upstream ports 20-1 to 20-5 and the downstream ports 22-1 to 22-5 of the distribution boards 12-1 to 12-5 are electrically turned on. , Off control is possible, and the port is turned on to enable communication, and the port is turned off to disable communication (blocking state).

  In the following description, when it is not necessary to distinguish the distribution boards 12-1 to 12-5, the up ports 20-1 to 20-5, and the down ports 22-1 to 22-5, the distribution board 12, the up port It may be referred to as port 20 and downstream port 22.

(Pseudo ring)
When the disaster prevention monitoring system shown in FIG. 1 is started up, the receiving panel 10 turns off its own S port 18 to disable communication. Thus, the transmission line 14 is physically a ring connection by connecting the receiving board 10 and the distribution boards 12-1 to 12-5, but the S port 18 on one side of the receiving board 10 is electrically connected. By setting the communication disabled state (blocking state), a so-called pseudo ring having a bus configuration in which the ring is disconnected on the S port 18 side of the receiver 10 is configured as a logical communication path.

  Therefore, even if a signal is transmitted from the receiver 10 or any of the distribution boards 12-1 to 12-5 to the transmission lines 14 on both the left and right sides, the signal is blocked by the S port 18 of the receiver 10 and terminated. An infinite loop in which the fragment turns does not occur, and the occurrence of a communication failure due to the infinite loop can be reliably prevented.

  In the data transmission by the token passing method, a network is constructed at the time of system startup, and tokens having node IDs # 1 to # 255 as destination IDs circulate on the transmission path 14. In the following description, the destination ID of the token is called a token ID. The details of the network construction will be clarified later.

  Due to the network construction, the token ID of the destination node to which the next token is to be passed is set in the receiving board 10 and the distribution boards 12-1 to 12-5 according to the logical ring connection order in the ascending order of the node IDs.

  That is, as the token ID for passing the token to the next board, the node ID = # 1 of the next distribution board 12-1 is set in the reception board 10, and the next distribution board 12- is set in the distribution board 12-1. 2 is set to node ID = # 2, the distribution board 12-2 is set to the node ID = # 3 of the next distribution board 12-3, and the distribution board 12-3 is set to the next distribution board 12-4. The node ID = # 4 is set, the node ID = # 5 of the next distribution panel 12-5 is set in the distribution panel 12-4, and the node ID = # 64 of the receiving panel 10 is set in the distribution panel 12-5. Set.

  Therefore, in the normal communication state after the completion of the network construction, tokens having token IDs # 1 to # 5 and # 64 circulate in the order of the receiving board 10 and the distribution boards 12-1 to 12-5. Here, the tokens of the tokens circulating on the transmission line 14 have only the destination ID and no source ID, so that the destination is known but the source is unknown.

  The receiving board 10 and the distribution boards 12-1 to 12-5 acquire the right to use when receiving a token having a token ID destined for their own node ID, and set in the network configuration when there is no data to be transmitted. A token having a token ID destined for the next node is transmitted to the transmission lines 14 on both the left and right sides.

  If the board that has obtained the right to use has data to send, an inquiry is made to the destination board as to whether or not it can be received. If a reception permission response is obtained, the source ID, destination ID and data Send a packet containing

[Configuration of network communication function of receiver]
FIG. 2 is a block diagram showing the configuration of the network communication function provided in the receiver. In FIG. 2, a line for sending data is indicated by a bold line.

As shown in FIG. 2, the network communication functions of the receiving board 10 include an M port 16, an S port 18, a network control unit 26, a board control unit 28, an operation unit 30, a display unit 32, and token ID detection units 60 and 62. Is provided, and the board control unit 28 has a function of the connection order detection unit 64.

(M port)
The M port 16 includes a receiving unit 34 that operates as a receiver and a transmitting unit 36 that functions as a driver. The input of the receiving unit 34 and the output of the transmitting unit 36 are connected to the transmission line 14 on the distribution board 12-3 side. I have. The output of the receiving section 34 is connected to the network control section 26 via an AND gate 46 functioning as a receiving gate switch of the port switching section 42.

  The AND gate 46 is turned on and off by a control signal E1 from the panel control unit 28, and when the control signal E1 is at the H level, the state becomes an allowable state (switch-on state) to enable reception, and the control signal E1 is at the L level. In this case, the state becomes the prohibited state (switch-off state) and the reception is disabled.

  The transmission unit 36 operates when the enable signal E5 from the network control unit 26 is turned on, and enters a transmission enabled state. When the enable signal E5 is turned off, the transmission unit 36 stops operating and enters the transmission disabled state. The enable signal E5 from the network control unit 26 is supplied to the transmission unit 36 via an AND gate 48 that functions as a transmission gate switch provided in the port switching unit 42.

  The AND gate 48 is turned on and off by a control signal E2 from the panel control unit 28, and when the control signal E2 is at the H level, it becomes an allowable state (switch-on state) to enable transmission, and the control signal E2 is at the L level. In this case, the transmission is prohibited and the transmission is disabled.

(S port)
The S port 18 includes a receiving unit 38 operating as a receiver and a transmitting unit 40 functioning as a driver. The S port 18 connects the input of the receiving unit 38 and the output of the transmitting unit 40 to the transmission line 14 on the distribution board 12-1 side. I have. The output of the receiving section 38 is connected to the network control section 26 via an AND gate 50 functioning as a receiving gate switch of the port switching section 44.

  The AND gate 50 is turned on and off by a control signal E3 from the board control unit 28. When the control signal E3 is at H level, it becomes an allowable state (switch-on state) to enable reception, and the control signal E3 is at L level. In this case, the state becomes the prohibited state (switch-off state) and the reception is disabled.

  The transmission unit 40 operates when the enable signal E6 from the network control unit 26 is turned on, and enters a transmission enabled state. When the enable signal E6 is turned off, the transmission unit 40 stops operating and enters the transmission disabled state. The enable signal E6 from the network control unit 26 is supplied to the transmission unit 40 via an AND gate 52 that functions as a transmission gate switch provided in the port switching unit 44.

  The AND gate 52 is turned on and off by a control signal E4 from the panel control unit 28. When the control signal E4 is at the H level, the transmission is enabled by setting the control signal E4 to the allowable state (switch-on state). In this case, the transmission is prohibited and the transmission is disabled.

(Network control unit)
The network control unit 26 performs network control based on the token passing method.

  After a network is constructed by starting up the system, in a normal communication state in which a token having a token ID destined to node IDs # 1 to # 5 and # 64 is circulating in the transmission path 14, for example, the M port 16 When a token having a token ID other than its own node ID is received from the receiving unit 34, an enable signal E6 is output to the transmitting unit 40 of the S port 18 to enable transmission, and the token is transmitted from the transmitting unit 40 of the S port 18. When the transmission is completed, the enable signal E6 is turned off.

  When a token having a token ID that matches the node ID of the own node is received from the receiving unit 34 of the M port 16, the token is output to the network control unit 26. The network control unit 26 obtains the usage right by receiving the token addressed to itself, but if there is no data to be transmitted, the network control unit 26 outputs the enable signals E5 and E6 after a predetermined chip-around time. The transmission unit 36 of the M port 16 and the transmission unit 40 of the S port 18 are set in a transmittable state, and a token having the token ID = # 1 destined for the next distribution board 12-1 is output to the transmission paths 14 on both the left and right sides. .

  On the other hand, if there is data to be transmitted to the network control unit 26, the reception permission is inquired to the destination board, and if a reception permission response is obtained, the enable signals E5 and E6 are output and the transmission of the M port 16 is performed. The unit 36 and the transmitting unit 40 of the S port 18 are set in a transmittable state, and transmit a packet including a destination ID, a source ID, and data to the transmission paths 14 on both the left and right sides.

(Panel control unit)
The board control unit 28 is a computer circuit including a CPU, a ROM, a RAM, various input / output ports, and the like. The board control unit 28 controls the transmission of various data related to disaster prevention monitoring between the distribution boards 12-1 to 12-5 by executing a program. Specifically, a packet including a destination ID, a source ID, and data is generated, and the packet is transmitted to the destination ID distribution board 12 via the transmission path 14 by the token passing method. Further, the board control unit 28 takes in the received data sent from the distribution board 12 and performs necessary display and control.

  Further, the panel control unit 28 has a control function of configuring a pseudo ring when the system is started up, and a control function of detecting a communication failure in the transmission line 14 and reconfiguring the pseudo ring.

  An operation unit 30 provided for the panel control unit 28 performs various setting operations required for the receiving panel 10. Further, the display unit 32 provided for the panel control unit 28 is, for example, a liquid crystal display with a touch panel, and displays various states such as port off.

(Token ID detector and connection order detector)
The token ID detection unit 60 is provided on the M port 16 side. The signal line connecting the reception unit 34 of the M port 16 and the AND gate 46 of the port switching unit 42 is branched and input-connected. The token ID of the token is detected and output to the board control unit 28.

  The token ID detection unit 62 is provided on the S port 18 side. The signal line connecting the reception unit 38 of the S port 18 and the AND gate 50 of the port switching unit 44 is branched and input and connected. The token ID of the received token is detected and output to the board control unit 28.

  The board control unit 28 has a function of a connection order detection unit 64 corresponding to the token ID detection units 60 and 62. The connection order detection unit 62 determines the distribution board 12 for the reception board 10 based on the token ID detection information detected and transmitted by the distribution boards 12-1 to 12-5 and the token ID detection information detected by the reception board 10 itself. The order of the physical ring connection of -1 to 15-5 is detected and stored.

  When a communication failure occurs in the transmission line 14, the board control unit 28 determines the location of the failure based on the physical ring connection order of the distribution boards 12-1 to 12-5 detected by the connection order detection unit 64. Upon detection, the fault location is separated, and the S port 18 of the receiving board 10 is changed to a state in which it can be electrically communicated to perform control to recover the communication fault.

  On the other hand, node ID detection units 60 and 62 are provided in the upstream port 20 and the downstream port 22 of the distribution boards 12-1 to 12-5, similarly to the M port 16 and the S port 16 of the reception board 10 in FIG. The node ID of the token received at each port is detected and output to the board control unit 28.

  The board control unit 28 of the distribution board 12 has a function of transmitting the detected token ID to the receiving board 10, and transmits the detected token ID information to the receiving board 10 at predetermined time intervals.

  Further, the board control unit 28 of the distribution board 12 has a function of detecting the valid token ID and transmitting it to the reception board 10. That is, the board control unit 28 of the distribution board 12 stores the same token ID as a valid token when detecting the same token ID within a predetermined time period in which the same token ID is obtained in the network configuration, and continuously stores the valid token plural times, for example, four times. If it is detected as a valid token, it is determined to be a true valid token, and the true valid token is transmitted to the receiver 10 as token detection information. The detection of the valid token is the same for the receiving board 10.

  This is because when a network is configured, a token having a token ID of # 1 to # 255 may be transmitted to the transmission line, and the token ID of a non-existent node may be erroneously detected. Erroneous token ID is prevented by detecting the true token ID based on the detection of the valid token ID.

  The connection order detection unit 64 of the receiver 10 controls the order of the physical ring connection of the distribution boards 12-1 to 12-5 to the receiver 10 based on the true valid token.

  Further, when a communication failure occurs in the transmission path, the board control unit 28 of the receiving board 10 performs control for detecting a failure location based on the token ID detection information obtained at that time.

[Configuration of network communication function of distribution board]
Configuration of the ring network communication function of the distributor 12 shown in FIG. 1, but becomes a network communication function is basically the same as that of the receiving plate 10 shown in FIG. 2, S port 18 of the receiving plate 10 is distributor 12 upstream The only difference is that the M port 16 of the receiver 10 corresponds to the port 20 and becomes the downstream port 22 of the distribution board 12. The outline of the detection of the token ID by the distribution board 12 and the transmission to the reception board 10 is as described above.

[Network control]
(Network management by timer)
First, the token passing method of the present embodiment is managed by the following three types of timers.
Network response timer T1 (= 78 μS)
Idle state detection timer T2 (= 86 μS)
Network status monitoring timer (T3 = 840 ms)

  When a timeout occurs with these timers, a transition is made from the abnormal state in the network to the next state. Normally, these timers will not time out if the network is operating properly. The meaning of each timer is as follows.

  The network response monitoring timer T1 is a timer for confirming that when a token is transmitted to the next node, the node receiving the token performs an operation such as transmitting the token next.

  When the network is operating properly, the idle state detection timer T2 always shows a token, which can be confirmed by each node. This operation occurs at regular time intervals, meaning that some node has been given the right to use the network. An idle state in a network is a state in which no node has the right to use, and it is necessary to immediately have some node have the right to use and transmit a token. It is the idle detection timer that controls this use right so that some node always has it.

  The network status monitoring timer T3 indicates that when a node participating in the network transmits a token to the next node (when a right to use is passed), sometime, the token is transmitted to its own node and the right to use is turned around. I will wait for it to come. If a token is received within this waiting time (the maximum waiting time of the network + the cable delay time), the timer is restarted.

  If the token cannot be received within the allotted time, it is determined that the user has not joined the network or has been disconnected, and the network needs to be reconfigured for rejoining. This is the network condition monitoring timer, which prevents network deadlock.

(Network construction)
Network construction is processing for establishing a logical ring by six nodes including the receiving board 10 and the distribution boards 12-1 to 12-15.

  Now, assuming that all of the receiving board 10 and the dispersing boards 12-1 to 12-5 are powered on at the same time and start operating, each of the six boards sends out a burst signal toward the transmission line 14. The burst signal is a kind of destruction signal that repeats a predetermined bit string, and prevents transmission from a board having the right to use the network, thereby creating a state in which there is no right to use anywhere.

  As a result, each board detects an idle state due to timeout of the idle state detection timer T2, and simultaneously starts network construction (reconfiguration). This network construction is also performed when a transmission path failure occurs, when a token is lost, when a new node joins the network, or when a participating node is deleted.

  For network construction, each board starts a (255-ID value) × 146 μS usage right acquisition timer, and the board that has timed out earliest acquires the usage right and starts sending tokens. In the present embodiment, since the node ID of the receiver 10 is the largest, # 64, the receiver 10 times out the earliest and starts sending the token.

  The receiving board 10 that has acquired the right to use sets its own node ID = # 64 in the NID register (NextID register) indicating the next node to which the token is to be sent, and transmits a token having # 64 as the token ID. Although there is no board that responds to the # 64 token transmitted by the receiving board 10, the distribution boards 12-1 to 12-5 that have received this token determine that some board has acquired the right to use, and The right acquisition timer is reset, and the network status monitoring timer T3 is started.

  In the receiving board 10 to which the token was first transmitted, there is no token from another board, so the network response timer T1 times out, and the receiving board 10 sets (# + 1) the # 64 of the NID register to # 65, and # 65. The next token having the token ID as is sent. By this repetition, a token whose token ID changes sequentially from # 64, # 65,... # 255, # 1 is transmitted from the receiver 10 at the cycle of the network response timer T1.

  Here, assuming that the receiving board 10 sets # 1 in the NID register and transmits the token, the distributing board 12-1 having the node ID = # 1 determines that it is a token for itself, and determines the right to use the network. Is recognized, the own node ID = # 1 is set in the NID register, and a token having # 1 as the token ID is transmitted before the 78 μs network response timer T1 times out.

  The token transmitted by the distribution board 12-1 is recognized by the reception board 10, and since the token is recognized within 78 μS when the network response timer T1 times out, it is determined that the use right has been passed to the board with the node ID = # 1, The receiving board 10 sets # 1 indicating the distribution board 12-1 in the NID register as the token ID indicating the next token destination.

  Hereinafter, the same processing is repeated in the order of the distribution boards 12-1 to 12-5 and the reception board 10, and the NID registers of the distribution boards 12-1 to 12-5 have token IDs used as the next destinations = # 2, # 3, # 4, # 5, and # 64 are set, and the network construction ends.

(Transmission sequence)
The sequence of data transmission between boards performed when the network construction is completed and tokens having # 1 to # 5 and # 64 as destination IDs are circulating on the transmission path is transmitted from the receiving board 10 to the distribution board 12-3. Taking the case of transmitting data as an example, it is as follows.

  Prior to data transmission, the receiving board 10 generates a packet including a source ID, a destination ID, and data of a predetermined length on a memory. When the receiving board 10 acquires the usage right by recognizing the token addressed to itself and sends a packet to the distribution board 12-3, the receiving board 10 transmits a free buffer inquiry FEB to the distribution board 12-3 which is the destination. Thereafter, one of the following three states occurs.

  If the destination distribution board 12-3 can receive the packet, it responds with ACK indicating reception permission. Receiving the ACK indicating reception permission, the receiving board 10 executes a packet transmission sequence, and receives an ACK indicating completion of reception from the distribution board 12-3, and ends the sequence.

  When the distribution board 12-3 responds to the transmission of the free banfa inquiry FEB from the reception board 10 with a NAK indicating that the reception is not permitted, the reception board 10 passes the token to the next distribution board 12-1. Wait for the next token for yourself.

  Furthermore, when there is no response from the distribution board 12-3 to the transmission of the free banfa inquiry FEB from the reception board 10, it is determined that the network is abnormal.

[Detection of distribution board connection order based on token ID]
FIG. 3 is an explanatory diagram showing a network configuration using a pseudo ring during normal communication, and FIG. 4 is an explanatory diagram showing token ID detection information detected during normal communication in FIG.

  At the time of normal communication shown in FIG. 3, the S port 18 of the receiver 10 is in a communication disabled state due to the port being turned off, as indicated by the mark x, and the M port 16 of the receiver 10 and the distribution boards 12-1 to 12-12. As shown by the circles, the upstream ports 20-1 to 20-5 and the downstream ports 22-1 to 22-5 of the -5 are in a communicable state by turning on the ports.

  Here, the order of the physical ring connection of the distribution boards 12-1 to 12-5 with respect to the reception board 10 is not ascending order # 1 to # 5, # 64 of each node ID. The order of the ring connection is ascending order # 1 to # 5, # 64 of each node ID, and a token having a token ID according to the ascending order is circulating on the transmission line 14.

  Specifically, under management control by the network response timer T1 of 78 μS, for example, the receiver 10 transmits a token having the token ID of # 1 from the M port 16 and the S port 18 to the transmission lines 14 on both the left and right sides. Since the port 18 is in a communication disabled state, a token having a token ID of # 1 circulates from the M port 16 counterclockwise on the transmission line 14.

  This token is acquired by the distribution board 12-1 in which the node ID of # 1 is set, and the distribution board 12-1 transmits the token having the token ID of # 2 from the upstream port 20-1 and the downstream port 22-1 to the left and right. To the road 14. Hereinafter, similarly, the distribution boards 12-2 to 12-4 transmit tokens, and the last distribution board 12-5 transmits a token having a token ID of # 64 to the left and right transmission lines 14, and transmits this token. The receiver 10 obtains the signal by receiving the M port 16, and this operation is repeated thereafter.

  By circulating the tokens having the token IDs # 1 to # 5 and # 64 during the normal communication on the transmission line 14, the receiving board 10 and the distribution boards 12-1 to 12-5 cause the token IDs shown in FIG. Obtain detection information.

  The token detection information shown in FIG. 4 is arranged in the order of the M port of the receiver 10, the pair of the upstream port 20 and the downstream port 22 of the distribution boards 12-1 to 12-5, and the S port 18 of the receiver 10. Regarding token IDs 1 to # 5 and # 64, ○ indicates that they could be detected, and X indicates that they could not be detected.

  From the token detection information in FIG. 4, the order of the physical ring connection of the distribution boards 12-1 to 12-5 can be determined, for example, as follows.

  (1) From the detection information of the uplink port 20-1 of the distribution board 12-1, the token IDs of # 1, # 3, # 4, # 5, and # 64 other than the token ID of # 2 transmitted by itself are visible. And distribution boards 12-2 to 12-5 having node IDs # 64, # 2, # 3, # 4, and # 5, one less than # 1, # 3, # 4, # 5, and # 64. Since the distribution board 12-1 exists on the upstream port 20-1 side, it is understood that the distribution board 12-1 is at the farthest end of the M port 16 of the reception board 10.

  (2) From the detection information of the upstream port 20-2 of the distribution board 12-2, # 1, # 4, and # 64 can be seen, and # 64, # 3, and # 1, which are one less than the upstream port 20-2. It can be seen that there are a receiver 1 having a node ID of 5 and distribution boards 12-3 and 12-5.

  (3) From the detection information of the downstream port 22-2 of the distribution board 12-2, # 2 and # 5 can be seen, and the downstream port 22-2 side has one less node ID of # 1 and # 4. It can be seen that the distribution boards 12-1 and 12-4 exist. Here, since the distribution board 12-1 is the farthest end in the above (1), it is understood that the distribution board 12-4 is adjacent to the downstream port 22-2 side of the distribution board 12-2.

  (4) From the detection information of the upstream port 20-3 of the distribution board 12-3, # 1 can be seen, and there is a receiver 10 having a node ID of # 64 which is one less than the # 1 on the upstream port 20-3 side. This indicates that the distribution board 12-3 is adjacent to the M port 16 side of the reception board 10. Therefore, it can be seen that the remaining dispersion board 15-5 is inevitably adjacent to the downstream port 22-3 side of the dispersion board 12-3.

  As a result, it can be determined that the distribution board is connected to the M port 16 of the reception board 10 in the order of 12-3, 12-5, 12-2, 12-4, and 12-1.

  FIG. 5 shows the token ID detection information of FIG. 4 in a state where the information is rearranged in the order of the determined physical ring connection.

[Disconnection failure and configuration control of pseudo ring]
FIG. 6 is an explanatory diagram showing an operation procedure of pseudo ring reconfiguration when a communication failure such as disconnection occurs in the transmission line, and FIG. 7 is detected when a communication failure occurs in the transmission line of FIG. FIG. 7 is an explanatory diagram showing token ID detection information.

(Judgment of fault location)
In the normal communication state shown in FIG. 3, as shown in FIG. 6A, it is assumed that a disconnection failure 70 occurs in the transmission line 14 connecting the distribution board 12-2 and the distribution board 12-4. The network forming the pseudo ring by the disconnection failure 70 includes a network including the receiver 10 and the distribution boards 12-3, 12-5, and 12-2, and a network including the distribution boards 12-4 and 12-1. The network is divided and a logical ring connection network in which the distribution boards 12-2, 12-3, and 12-5 are connected to the reception board 10 in order, and the distribution boards 12-1 and 12-4. Are sequentially connected to form a logical ring connection network.

  FIG. 7 shows the node ID detection information detected after the disconnection failure 70 in FIG. 6A has occurred and the network has been reconfigured.

  The board control unit 28 of the receiving board 10 determines from the token ID detection information in FIG. 7 that the disconnection failure 70 has occurred in the transmission line 14 between the distribution board 12-4 and the distribution board 12-2. This means that all node IDs are not visible at the downstream port 22-2 of the distribution board 12-2 and the upstream port 20-4 of the distribution board 12-4, and it can be determined that the disconnection failure 70 has occurred during this time.

  The board controller 28 of the receiver 10 determines the location of the failure by recognizing the order of the physical ring connection of the distribution boards 12-1 to 12-5 to the receiver 10. A predetermined search packet is transmitted to 12-1 to 12-5. In this case, since the distribution boards 12-4 and 12-1 do not respond, the distribution packet is transmitted between the distribution boards 12-2 and 12-4. It can be determined that the disconnection failure 70 has occurred.

(Reconstruction of pseudo ring)
When the receiving board 10 determines the location of the occurrence of the disconnection failure 70 in the transmission path 14, as shown in FIG. 6B, the downstream port 22 located on the failure side with respect to the distribution board 12-2 located in front of the failure location. A port-off control packet 72 for instructing to turn off the port-2 is transmitted. The port off control packet 72 includes a distribution board 12-2 as a destination ID, a reception board 10 as a transmission source ID, and includes an off control command for the downstream port 22-2.

  The distribution board 12-2 that has received the port-off control packet 72 from the reception board 10 turns off the downstream port 22-2 and switches to the communication disabled state as shown in FIG. The data is transmitted to the receiving panel 10.

  The switching to the communication disabled state due to the turning off of the downstream port 22-2 by the distribution board 12-2 corresponds to the port off of the M port 16 of the receiving board 10 in FIG. 2 and is provided from the board control unit 28 to the port switching unit 42. By setting the control signals E1 and E2 for the AND gates 46 and 48 to L level and disabling the AND gates 46 and 48, the output of the receiving unit 34 of the M port 16 is disconnected to disable reception. The supply of the enable signal E5 to the transmission unit 36 of the port 16 is stopped, and the transmission is disabled.

  Subsequently, as shown in FIG. 6D, the receiving board 10 which has received the ACK 74 from the distribution board 12-2 changes the S port 18 which has been in a communication disabled state due to the port off to a communication enabled state due to the port on. Switch. That is, the control signals E3 and E4 for the AND gates 50 and 52 provided in the port switching unit 44 from the board control unit 28 of the receiving board 10 shown in FIG. 2 are changed from L level to H level, and the AND gates 50 and 52 are allowed. Thus, the output of the receiving unit 38 of the S port 18 is connected to the network control unit 26 to enable reception, and at the same time, the enable signal E6 can be supplied to the transmitting unit 40 of the S port 18 to enable transmission. And

  As a result, in the network configuration shown in FIG. 6 (D), the pseudo ring cut at the location where the disconnection failure 70 occurred between the distribution board 12-2 and the distribution board 12-4 was reconfigured. The communication between all nodes consisting of 10 and the distribution boards 12-1 to 12-5 is restored, and the state can be shifted to the normal communication state by the reconfigured pseudo ring.

  Also in this case, even if a signal is transmitted from the receiving board 10 or any one of the distribution boards 12-1 to 12-5 to the transmission lines 14 on both the left and right sides, the signal is transmitted between the distribution board 12-3 and the distribution board 12-4. Blocking occurs at the location where the disconnection failure 70 has occurred and the down port 22-2 in which the distribution board 12-2 has become unable to communicate, and the processing is terminated, and an infinite loop in which a signal fragment turns does not occur. The occurrence of a communication failure can be reliably prevented.

[Reconstruction of pseudo ring when disconnection failure is resolved]
During the normal communication by the reconfiguration of the pseudo ring with respect to the disconnection failure 70 shown in FIG. 6D, the disconnection failure 70 is resolved by the repair work, and the transmission line 14 is connected between the distribution board 12-2 and the distribution board 12-4. In this case, the receiver 10 performs a reconfiguration to return to the pseudo ring shown in FIG.

First, the receiving board 10 instructs its own S port 18 to be turned off, and switches the S port 18 to a communication disabled state (blocking state). Subsequently, the receiving board 10 transmits a port-on control packet to the distributing board 12-2 in which the downstream port 22-2 is turned off and communication is disabled in response to the occurrence of the disconnection failure 70.

  The distribution board 12-2 that has received the port-on control packet from the reception board 10 turns on the downstream port 22-2 which is currently in the communication disabled state due to being turned off, and switches to the communication enabled state. As a result, the same pseudo ring as the initial setting in which the S port 18 of the receiver 10 is in the communication disabled state is reconfigured.

  Here, if the downstream port 22-2 of the distribution board 12-2 is turned on first, a complete ring in which the transmission paths 14 are connected in a ring shape is formed, and the possibility of causing a communication failure due to an infinite loop is increased. In the present embodiment, the S port 18 of the receiver 10 is turned off first to disable communication, and then the downstream port 22-2 of the distribution board 12-2 is turned on to enable communication. Looping is suppressed.

[Control operation of receiver]
FIG. 8 is a flowchart showing the control operation of the receiving board. As shown in FIG. 8, when the receiving board 10 starts up by turning on the power, the network configuration is executed based on the transmission of the burst signal to the transmission line 14 in step S1, and the distribution board 12- indicating the next token destination in the register NID. The node ID of # 1 = # 1 is set as the token ID, and the process proceeds to the data transmission process of step S2.

  In the data transmission process of step S2, the token having the token ID = # 64 is recognized to acquire the right to use, the free buffer inquiry FEB is transmitted to the destination board of the data transmission, and the ACK indicating the reception permission is received. Then, the packet is transmitted.

  Also, when a free buffer inquiry FEB addressed to itself is received from the board that has acquired the right to use, if it can be received, an ACK indicating that is received, a packet is received, and data included in the received packet is received. Display and control based on

  Subsequently, based on the token detection information transmitted from the distribution boards 12-1 to 12-5 in step S3, the order of the physical ring connection of the distribution boards 12-1 to 12-5 to the receiving board 10 is detected and transmitted. Prepare for road failure.

  During normal communication in which the data transmission process of step S2 and the token ID detection of step S3 are repeated, if a communication failure such as disconnection of the transmission line is determined in step S4, the process proceeds to step S5, and after the network reconfiguration due to the transmission line failure, The obtained token ID detection information is used to search for a faulty location where a transmission line fault has occurred, and the process proceeds to step S6, where a port-off control packet is transmitted to a board located in front of the faulty location as a faulty location isolation process. The communication is disabled by turning off the port 22.

  Subsequently, when the disconnection acknowledgment ACK is received from the distribution board 12 which is the destination of the port-off control packet in step S7, the process proceeds to step S8, where the own S port 18 is turned on to enable communication. As a result, in step S9, the pseudo ring whose ring is logically broken at the point of occurrence of the failure is reconfigured, a normal communication state in which data can be transmitted between all boards is established, and data transmission is performed.

  Subsequently, when it is determined in step S10 that the failure has been resolved, the S port 18 is turned off to switch to the communication disabled state in step S11, and a port-on control packet is transmitted to the distribution board 12 having the downstream port 22 turned off in step S12. Then, the communication is enabled by turning on the downstream port 22. By the processing in steps S11 and S12, the same pseudo ring as the initial setting in which the ring is logically disconnected on the S port 18 side of the receiving board 10 is reconstructed, and normal communication enabling data transmission between all boards is performed. State.

[Modification of the present invention]
Although the above-described embodiment has been described by taking the fire prevention monitoring system for monitoring a fire as an example, the present invention can be similarly applied to a fire prevention monitoring system that detects an appropriate abnormality such as a gas leak or theft other than a fire and issues an alarm. .

  Further, the present invention is not limited to the above embodiments, includes appropriate modifications without impairing the objects and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

10: receiving boards 12-1 to 12-5: distribution board 14: transmission line 16: M port 18: S ports 20-1 to 20-5: uplink ports 22-1 to 22-5: downlink port 26: network control Unit 28: board control unit 30: operation unit 32: display units 34, 38: reception units 36, 40: transmission units 42, 44: port switching units 46, 48, 50, 52, 56, 58: AND gates 60, 62 : Token ID detection unit 64: Connection order detection unit 70: Disconnection failure 72: Port off control packet

Claims (8)

In a disaster prevention monitoring system that performs data transmission by ring-connecting a parent node and a plurality of child nodes via a transmission path,
By setting one of the ports of the parent node to an electrically uncommunicable state, a logical bus-type communication path is formed,
Each of the ports provided in the parent node and each of the child nodes is provided with a token ID detection unit that detects a token ID that is an identifier of the received token,
The parent node and the child node each transmit a signal including a different token ID,
The token ID detection unit physically detects a token ID included in a signal transmitted from a parent node and a child node on a preceding stage, and stores token ID detection information indicating which token ID has been detected. ,
The child node transmits the detected token ID detection information to a parent node,
The disaster prevention monitoring system according to claim 1 , wherein the parent node includes a connection order detection unit that detects a ring connection order based on the token ID detection information transmitted from the child node.
The disaster prevention monitoring system according to claim 1,
When a communication failure occurs in the transmission path, a failure location is detected based on the token ID detection information in the parent node and / or the child node after the failure and the order of the physical ring connection, and the failure location is disconnected. A disaster prevention monitoring system, comprising: a control unit for recovering the communication failure by changing the one-side port of the parent node to an electrically communicable state at the same time.
In a disaster prevention monitoring system that performs data transmission by ring-connecting a parent node and a plurality of child nodes via a transmission path ,
By setting one of the ports of the parent node to an electrically uncommunicable state, a logical bus-type communication path is formed,
A token ID, which is an identifier of the received token, is detected in each of the ports provided in the parent node and each of the child nodes. If the same token ID is detected within a predetermined time, the token ID is stored as a valid token. Provided a token ID detection unit that determines that the token is a true valid token when the token is detected a plurality of times in succession,
In the parent node,
A connection order detection unit that detects an order of a physical ring connection of the plurality of child nodes to a parent node based on the token ID detection information including the true valid token detected by the token ID detection unit;
When a communication failure occurs in the transmission path, a failure location is detected based on the physical ring connection order and the token ID detection information detected by the token ID detection unit, and the failure location is disconnected and A control unit that changes the one-side port of the parent node to an electrically communicable state and recovers the communication failure,
Disaster prevention monitoring system characterized by having provided .
In the disaster prevention monitoring system according to claim 2 or 3 ,
Each of the parent node and the child node has a first port and a second port including a transmission unit and a reception unit,
The first port and the second port are:
A receiving-side gate switch that is provided on the output side of the receiving unit and that switches between a receivable state or a non-receivable state at ON and OFF by a control signal from the control unit,
A transmission-side gate switch that is provided on a control line that turns on and off the transmission operation of the transmission unit, and that switches a transmission-enabled state or a transmission-disabled state by an on-off control signal from the control unit,
With
A detection point by the token ID detection unit is provided between the output of the reception unit and the input of the reception side gate switch, and the token ID is set in any state in which each of the ports is switched to the communication enabled state or the communication disabled state. Disaster prevention monitoring system characterized by being detectable.
In the disaster prevention monitoring system according to claim 4,
As an initial setting,
The control unit of the parent node turns on the first port to set a communicable state, and turns off the second port to set a communicable state.
The control unit of the child node turns on the first and second ports to set a communicable state,
When a communication failure occurs in the transmission path,
The control unit of the parent node transmits a port-off control signal for instructing the second node on the failure side to be turned off to a child node located before the failure point, and receives an acknowledgment control signal for the port-off control signal. In this case, the second port is turned on to switch to a communicable state,
The control unit of the child node, when receiving the port off control signal from the parent node, turns off the second port to switch to a communication disabled state and transmits an acknowledgment control signal to the parent node. Disaster prevention monitoring system featuring.
In the disaster prevention monitoring system according to claim 5 ,
When the communication failure is resolved,
The control unit of the parent node turns off the second port, sets the communication disabled state, and transmits a port-on control signal that instructs the child node that has transmitted the port-off control signal to turn on a port,
The control unit of the child node, which sets the second port to the communication disabled state by the port off control signal from the parent node, turns on the second port when receiving the port on control signal from the parent node. A disaster prevention monitoring system characterized by switching to a communication enabled state.
The disaster prevention monitoring system according to any one of claims 1 to 6, wherein the parent node is provided on a receiving board, the plurality of child nodes are provided on a plurality of distribution boards, and the receiving board and the plurality of distribution boards are provided. Disaster prevention monitoring system characterized in that data is transmitted between
In the disaster prevention monitoring system according to claim 7,
The first port of the parent node provided in the receiver is a main port on the side that constantly communicates, and the second port is a secondary port on the side that does not always communicate,
And uplink port located a first port of the child node provided in the distributor to the main port side of the parent node, characterized in that the second port and a down port located on the secondary port side of the parent node Disaster prevention monitoring system.

Images