CN111416750A - Fault monitoring system and monitoring method of single-network-line Ethernet ring network - Google Patents
Fault monitoring system and monitoring method of single-network-line Ethernet ring network Download PDFInfo
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- CN111416750A CN111416750A CN202010406470.3A CN202010406470A CN111416750A CN 111416750 A CN111416750 A CN 111416750A CN 202010406470 A CN202010406470 A CN 202010406470A CN 111416750 A CN111416750 A CN 111416750A
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 20
- 238000011144 upstream manufacturing Methods 0.000 claims description 28
- 239000013078 crystal Substances 0.000 claims description 9
- 238000012423 maintenance Methods 0.000 claims description 5
- 238000004891 communication Methods 0.000 abstract description 6
- 238000011084 recovery Methods 0.000 abstract description 5
- 230000002159 abnormal effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
- H04L41/06—Management of faults, events, alarms or notifications
- H04L41/0631—Management of faults, events, alarms or notifications using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/42—Loop networks
- H04L12/437—Ring fault isolation or reconfiguration
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
- H04L41/06—Management of faults, events, alarms or notifications
- H04L41/0654—Management of faults, events, alarms or notifications using network fault recovery
Abstract
The invention discloses a fault monitoring system and a fault monitoring method of a single-network-cable Ethernet ring network, which comprises the steps of utilizing specially customized Ethernet MAC control equipment and a normal-sequence network cable, utilizing two groups of cables of a channel I and a channel II of the normal-sequence network cable to form two independent channels, and connecting the network cable into a port I and a port II of the equipment in a hand-in-hand topology manner; the host device sets the channel I as a receiving and sending mode, sets the channel II as a monitoring mode, if the channel II receives a response command response after sending a command, the normal work of all nodes on the ring network is indicated, if the channel II cannot receive any response after sending the command, or the slave device returns an interrupt command frame, the fault of the ring network node is indicated, the position of the fault node is automatically judged, and the connection topology of the system is changed to realize the recovery. The method can enhance the communication disaster tolerance and self-healing capability of the system on the basis of realizing the communication function of accessing the master and slave equipment, and only uses a single traditional network cable, thereby reducing the engineering quantity of the system applying the method.
Description
Technical Field
The invention belongs to the field of automation, belongs to the field of automation control, and relates to an application scene of long-chain topology and master-slave control, in particular to a fault monitoring system of a single-network-line Ethernet ring network.
Background
At present, the requirement for fine monitoring control in each industry is higher and higher, in order to control and monitor each tail end unit, monitoring equipment needs to be independently arranged at each point, the reliability of the monitoring equipment in off-site operation is often not guaranteed due to various factors such as climate, environment and the like, a single bus is easy to be unstable due to too long distance, interface resources are wasted by star topology, and the wiring construction cost is increased.
Disclosure of Invention
In order to solve the problems of high cost and instability in the prior art, the invention provides a single-network-line Ethernet ring network organization and fault monitoring system and a monitoring method thereof for the field of automation control, so that the reliability and stability of the system are ensured while the project wiring construction cost is reduced.
The technical scheme of the invention is as follows: a fault monitoring system of single network cable Ethernet looped network comprises a looped network link head end device, a plurality of looped network link internal slave devices, a looped network link end device and a network cable; the ring network link head end equipment is provided with a network interface with double network cards; the network interface divides a network cable into two ring network ports; the slave equipment in the ring network link and the end equipment of the ring network link are respectively provided with an upstream network interface and a downstream network interface; and one ring network port is connected with the ring network link end equipment.
Specifically, the two ring network ports are respectively the 1 st, 2 nd, 3 th and 6 th network cables and the 4 th, 5 th, 7 th and 8 th network cables.
More specifically, the 4 th, 5 th, 7 th and 8 th network cables are connected with ring network link end equipment.
More specifically, the network cable access of the ring network link end device is as follows: connecting No. 1, 2, 3 and 6 network cables to the corresponding positions of the crystal heads and connecting the crystal heads to an upstream network interface; and connecting the network cables 4, 5, 7 and 8 into the positions 1, 2, 3 and 6 of the crystal heads, and connecting the network cables into a downstream network interface.
Specifically, the slave devices in the plurality of looped network links and the looped network link end device are connected in a hand-in-hand mode by using a network cable.
A monitoring method of fault monitoring system of single network line Ethernet looped network, there are two kinds of data frame formats of order and inquiry between slave unit in said looped network link head end equipment and looped network link; the command frame is sent by the ring network link head end equipment, the upstream node continuously forwards the command frame to the downstream node after receiving the command frame, the downstream node sends a response to the upstream node, and the upstream node does not forward the command frame after receiving the response; finally, the command is recycled by the main equipment; the query frame is sent by the ring network link head-end equipment, after the query frame is received by the upstream node, the upstream node firstly responds to the node at the higher level, and then continuously sends the query frame to the downstream equipment; finally, the query is recycled by the master device.
Specifically, if the upstream node cannot obtain the response data of the downstream node within a specified time after sending the query or command frame to the downstream node, or the head-end device of the ring network link cannot receive the frame of the tail-end node within a specified time, it determines that the ring network is interrupted, and sends the interrupt command frame to the upper-level node.
Specifically, the ring network link head-end device records after receiving the interrupt command frame, responds to the interrupt node, and uses one of the ports to send data to the ring network link end device, the ring network topology changes into two long-chain topology modes, and the interrupt node does not send data to the downstream node any more.
Specifically, if the interrupted node resumes normal operation after maintenance, the ring network link head-end device sends a normal operation command to the ring network through one of the ports, and resumes the ring network topology.
Compared with the prior art, the invention has the beneficial effects that: on the basis of realizing the communication function of accessing master and slave equipment, the communication disaster tolerance and self-healing capability of the system are enhanced, and the engineering quantity of the system applying the method is reduced by only using a single traditional network cable; the method can provide a new solution for data stream transmission, management, fault monitoring and fault tolerance for the field of automatic control monitoring application.
Drawings
FIG. 1 is a diagram of initial wiring and normal links according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an abnormal transmission condition according to the present invention;
FIG. 3 is a schematic diagram of a network link after abnormal automatic recovery in accordance with the present invention;
in the figure: 1-ring network link head-end equipment; 2-a plurality of ring network link internal slave devices; 3-ring network link end equipment; 4-network cable; 5-a network interface; 6-ring network port.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A fault monitoring system and its monitoring method of the Ethernet looped netowrk of single network line, this system includes a looped netowrk periodic line head end apparatus 1, several looped netowrk periodic line interior slave units 2, looped netowrk periodic line end apparatus 3 and network line 4; the looped network link head end equipment 1 is provided with a network interface 5 with a double network card, and the network interface 5 divides the 1 st, 2 nd, 3 th and 6 th network cables and 4 th, 5 th, 7 th and 8 th network cable into two looped network ports 6; the slave device 2 in the ring network link and the ring network link end device 3 have the same structure; the network connection device is provided with an upstream network interface 5 and a downstream network interface 5 respectively, the numbers 4, 5, 7 and 8 of network cables are connected in the ring network link end equipment 3, and the slave equipment 2 in the ring network link is connected in a hand-in-hand mode by using the network cables 4; the internal structure of the ring network link end equipment 3 is consistent with that of the ring network link slave equipment 2, but the access mode of the network cable 4 is as follows: the network lines 1, 2, 3 and 6 are connected to the corresponding positions of the crystal heads and are connected to the upstream network interface 5, and the network lines 4, 5, 7 and 8 are connected to the positions of the crystal heads 1, 2, 3 and 6 and are connected to the downstream network interface 5.
The invention constructs a chain type Ethernet ring network consisting of a master device 2 and a plurality of slave devices 2, which is mainly characterized in that a manual-manual chain connection of a single network cable 4 is utilized, and an automatic communication network with stronger disaster tolerance capability is formed through the logical and physical connection in the devices in the chain. Assume that a ring network link head-end device 1 is a, another B, C, D, E is a ring network link slave device 2, and E is a ring network link end device 3. As shown in fig. 1, the system connection method uses all 8 cables of the network cable 4 for the ring network link head end device a, and divides cables No. 1, 2, 3, 6, 4, 5, 7, 8 into two groups of network ports, which are assumed to be port one and port two, respectively. The slave B, C, D in the ring network link has two independent network interfaces 5, which are assumed to be interface one and interface two, respectively, and both interfaces perform controlled communication by using network lines 1, 2, 3, and 6, and physically connect the network line interfaces 4, 5, 7, and 8 together inside. For the ring network link end equipment E, the internal design is completely consistent with that of slave equipment 2 in other ring network links, the No. 1, 2, 3 and 6 wires of the network cables are pressed into the network connector in sequence and then connected into an equipment interface I, and the No. 4, 5, 7 and 8 wires are pressed into the No. 1, 2, 3 and 6 positions of the network connector and then connected into an equipment interface II, so that the connection of the ring network is completed.
Two groups of cables of No. 1, No. 2, No. 3 and No. 6 (channel I) and No. 4, No. 5, No. 7 and No. 8 (channel II) of the normal line sequence network cable form two independent channels, and the network cable 4 is connected into an upstream ring network interface (port I) and a downstream ring network interface (port II) of the equipment in a hand-in-hand topology manner. The inside of the equipment is directly connected with the first access port and the second channel of the second network cable 4 in an internal connection mode. And at the tail end position in the hand-in-hand connection topology, independently pressing the first channel and the second channel into the network crystal head, pressing the network cables 4, 5, 7 and 8 into the positions of the crystal heads 1, 2, 3 and 6, and connecting the first channel into a first port of the tail end equipment 3 and connecting the second channel into a second port of the equipment. At the head end position of the hand-in-hand connection topology, the host device sets the channel I as a transceiving mode, sets the channel II as a monitoring mode, if the channel II receives a response command response after sending a command, the normal work of all nodes on the ring network is indicated, if the channel II cannot receive any response after sending the command, or the slave device returns an interrupt command frame, the fault of the ring network node is indicated, the channel II can be switched into the transceiving mode in time, meanwhile, a check command is sent out on the channel I and the channel II, the position of the fault node is automatically judged through the step-by-step response of the slave device 2 in the ring network link, and the system connection topology is changed to realize the recovery.
The inside of the whole ring network controls all the slave devices 2 in the ring network link through the master device of the head end device 1 of the ring network link, and the data frame is divided into two formats of 'command' and 'inquiry'. Aiming at the command frame, the command frame is sent by the ring network link head end equipment 1, the upstream node continuously forwards the command frame to the downstream node after receiving the command frame, the downstream node sends a response to the upstream node, and the upstream node does not forward the command frame after receiving the response. Finally, the command is recycled by the main equipment; the command frame is sent by the ring network link head-end equipment 1, after the upstream node receives the command frame, the upstream node firstly responds to the node at the higher level, and then continuously sends the query frame to the downstream equipment. Finally, the query is recovered by the main equipment; the concrete explanation is as follows: the device A at the head end of the ring network link sends out the command, the device B in the ring network link receives the command, then the command is sent down and directly sent to the device C, the device B returns a command response to the device A after executing the command, and the command frame is transmitted to the device A continuously by the device E at the tail end of the ring network link, so that the cycle is completed. For the inquiry frame, the equipment 1A at the head end of the ring network link sends the inquiry frame to the equipment C, the equipment C receives the data and transmits the data to the downstream node equipment D, then the equipment C packages the inquiry data and transmits the inquiry data to the upstream node equipment B after processing, the equipment B transmits the data to the more upstream equipment, and then the equipment E at the tail end of the ring network link continuously transmits the inquiry frame to the equipment A, thereby completing the cycle.
Two data frames can be accompanied by a slave device 2 feature identification number, thereby realizing more accurate control.
In the abnormal state shown in fig. 2, if the upstream node cannot obtain the response data of the downstream node within the specified time after sending the query or command frame to the downstream node, or the ring network link head-end device 1 cannot receive the frame of the end node within the specified time, it is determined that the ring network is interrupted, and the slave device sends the interrupt command frame to the upper-level node; the concrete explanation is as follows: if a line between equipment C or B, C in the ring network cannot work normally due to a fault, after a data frame is sent from a head-end equipment 1 of a ring network link to equipment B, the equipment B sends the data frame to the equipment C, but cannot receive a response from the equipment C within a set time range, the line between the equipment C or B, C is considered to have the fault, and fault information is reported, after the equipment a receives the fault response, a fault checking command frame is directly sent to a tail-end equipment E through a port two, if the equipment E does not reply a signal within a specified time after sending, it can be judged that the line between B, C has the fault, and if the equipment a can receive the response from the equipment D, the fault of the equipment C is indicated.
The ring network link head end equipment 1 records after receiving the interrupt command frame, responds to the interrupt node, and uses the port to send data to the other end of the ring network, the ring network topology is changed into two long chains, and the interrupt node does not send data to the downstream node any more. If the interrupted node recovers normal operation after maintenance, the head-end equipment 1 sends a normal operation command to the ring network through the port to recover the ring network topology; the concrete explanation is as follows: after the fault is located, if the slave device 2 fails, the device a processes the fault record, and then sends a recovery command to the slave device 2 through the port one and the port two, respectively, to recover the system to the dual long-chain topology mode shown in fig. 3, where the two links are a- > B and a- > E- > D, respectively. If the line is in fault, the uninterrupted link part is continuously used to wait for maintenance. If the ring network is repaired after maintenance, a normal recovery command frame is sent through the equipment A, so that the whole ring network is recovered to a normal working state.
The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention.
Claims (9)
1. The utility model provides a fault monitoring system of single net twine ethernet looped netowrk which characterized in that: the system comprises a ring network link head end device (1), a plurality of ring network link internal slave devices (2), a ring network link tail end device (3) and a network cable (4); the ring network link head end equipment (1) is provided with a network interface (5) with double network cards; the network interface (5) divides the network cable (4) into two ring network ports (6); the slave equipment (2) in the ring network link and the ring network link end equipment (3) are respectively provided with an upstream network interface (5) and a downstream network interface (5); one ring network port (6) is connected with ring network link end equipment (3).
2. A fault monitoring system for a single-wire ethernet ring network as claimed in claim 1, wherein: the two looped network ports (6) are respectively No. 1, No. 2, No. 3 and No. 6 network cables and No. 4, No. 5, No. 7 and No. 8 network cables.
3. A fault monitoring system for a single-wire ethernet ring network as claimed in claim 2, wherein: the slave equipment (2) in the ring network link is connected with the ring network link end equipment (3) through No. 4, No. 5, No. 7 and No. 8 network cables.
4. A fault monitoring system for a single-wire ethernet ring network as claimed in claim 2, wherein: the access of the network cable (4) of the ring network link terminal equipment (3) is as follows: connecting the No. 1, 2, 3 and 6 network cables to the corresponding positions of the crystal heads and connecting the network cables to an upstream network interface (5); and connecting the network cables 4, 5, 7 and 8 into the positions 1, 2, 3 and 6 of the crystal heads, and connecting the network cables into a downstream network interface (5).
5. A fault monitoring system for a single-wire ethernet ring network as claimed in claim 1, wherein: the slave equipment (2) in the plurality of looped network links and the looped network link end equipment (3) are connected in a hand-in-hand mode by using the network cable (4).
6. The method according to any one of claims 1 to 5, wherein the method comprises the following steps: two data frame formats of command and query are provided between the ring network link head end equipment (1) and the slave equipment (2) in the ring network link; the command frame is sent by the ring network link head end equipment (1), the upstream node continuously forwards the command frame to the downstream node after receiving the command frame, the downstream node sends a response to the upstream node, and the upstream node does not forward the command frame after receiving the response; finally, the command is recycled by the main equipment; the query frame is sent by the ring network link head end equipment (1), after the upstream node receives the query frame, the upstream node firstly responds to a node at a higher level, and then continuously sends the query frame to downstream equipment; finally, the query is recycled by the master device.
7. The method according to claim 6, wherein the monitoring method comprises the following steps: if the upstream node cannot obtain the response data of the downstream node within the specified time after sending the query or command frame to the downstream node, or the ring network link head-end equipment (1) cannot receive the frame of the tail-end node within the specified time, the ring network is judged to be interrupted, and the interrupt command frame is sent to the upstream node.
8. The method according to claim 7, wherein the monitoring method comprises the following steps: the ring network link head end equipment (1) records after receiving the interrupt command frame, responds to the interrupt node, and uses one port to send data to the ring network link end equipment (3), the ring network topology is changed into two long chain topology modes, and the interrupt node does not send data to the downstream node any more.
9. The method according to claim 7 or 8, wherein the method comprises the following steps: if the interrupted node resumes normal operation after maintenance, the ring network link head-end equipment (1) sends a normal operation command to the ring network through one of the ports, and resumes the ring network topology.
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| CN202010406470.3A CN111416750A (en) | 2020-05-14 | 2020-05-14 | Fault monitoring system and monitoring method of single-network-line Ethernet ring network |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113452577A (en) * | 2021-06-25 | 2021-09-28 | 维沃移动通信有限公司 | Abnormity detection method and device and electronic equipment |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070165517A1 (en) * | 2006-01-16 | 2007-07-19 | Stefano Binetti | Recovery mechanism for 10 ge optical transport network wavelength division multiplexing ring |
| CN101741674A (en) * | 2009-12-22 | 2010-06-16 | 上海自动化仪表股份有限公司 | Method for realizing redundant ring and network recovery in Ethernet |
| CN104135417A (en) * | 2014-08-27 | 2014-11-05 | 杭州立地信息技术有限公司 | Quick recovery method for ethernet ring network link interruption and corresponding ethernet ring network |
| CN106059945A (en) * | 2016-05-13 | 2016-10-26 | 浙江宇视科技有限公司 | Flow control method and video monitoring system |
-
2020
- 2020-05-14 CN CN202010406470.3A patent/CN111416750A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070165517A1 (en) * | 2006-01-16 | 2007-07-19 | Stefano Binetti | Recovery mechanism for 10 ge optical transport network wavelength division multiplexing ring |
| CN101741674A (en) * | 2009-12-22 | 2010-06-16 | 上海自动化仪表股份有限公司 | Method for realizing redundant ring and network recovery in Ethernet |
| CN104135417A (en) * | 2014-08-27 | 2014-11-05 | 杭州立地信息技术有限公司 | Quick recovery method for ethernet ring network link interruption and corresponding ethernet ring network |
| CN106059945A (en) * | 2016-05-13 | 2016-10-26 | 浙江宇视科技有限公司 | Flow control method and video monitoring system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113452577A (en) * | 2021-06-25 | 2021-09-28 | 维沃移动通信有限公司 | Abnormity detection method and device and electronic equipment |
| CN113452577B (en) * | 2021-06-25 | 2024-02-06 | 维沃移动通信有限公司 | Abnormality detection method and device and electronic equipment |
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