CN114006785A

CN114006785A - Single-twisted-pair TSN passive coupler and design method

Info

Publication number: CN114006785A
Application number: CN202111339601.1A
Authority: CN
Inventors: 王红春; 张家超; 付勇; 张盼红; 李宁; 杨元伟
Original assignee: Xi'an Yunwei Zhilian Technology Co ltd
Current assignee: Xi'an Yunwei Zhilian Technology Co ltd
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2022-02-01

Abstract

The invention provides a single-twisted-pair TSN passive coupler and a design method thereof, wherein the design method comprises the following steps: step one, realizing the double-wire Ethernet communication; step two, realizing power supply of the double-wire Ethernet; thirdly, power supply relay access; step four, three-port TSN exchange is realized; step five, the compatibility to the common Ethernet interface; step six, establishing a time scheduling mechanism based on gating; dividing the data priority; eighthly, implementing multi-node hybrid networking; and step nine, realizing centralized network configuration. The coupler can realize distributed connection of TSN network nodes, the connection adopts a single twisted pair, and the communication bandwidth is 1000 Mbps. The double-line power supply coupler of the invention realizes passive connection of network nodes, makes the nodes access to the network simpler and more convenient, and reduces cables. The method is suitable for the fields of network communication and real-time control, and has the characteristics of few cables and simplicity in use.

Description

Single-twisted-pair TSN passive coupler and design method

Technical Field

The invention belongs to the technical field of communication, relates to a distributed real-time control network, and particularly relates to a single-twisted-pair TSN passive coupler and a design method thereof.

Background

The field of distributed network communications and real-time control networks has special requirements for network topology, bandwidth allocation and power supply over traditional ethernet networks.

Topological aspect, in the conventional ethernet, a node needs to access a network using a switch or a hub, and the network topology can be a star, a ring, a tree, a bus, and a mesh structure. However, in the field of distributed network communication and real-time control, network communication nodes are usually far away, and the traditional network topology depends on interconnection of switches, so that the use is inconvenient. In order to solve the above problems, in the control field, a network topology using daisy chain connection is provided, each network node generally has 2 ports, and the ports are connected end to end, but this technique still uses 4 pairs of common differential cable network cables, which is inconvenient to apply in some fields having strict requirements on cable cost, cable weight and wiring space.

In the aspect of bandwidth, in a traditional network system which uses switches for interconnection, all nodes can simultaneously realize full-bandwidth high-speed communication, but the nodes use a CSMA/CD (carrier sense multiple access/collision detection) mechanism to avoid collision, which introduces uncertain network transmission delay and is not suitable for the control field. While the networks of the hub and the daisy chain topology are bandwidth-shared, although some dedicated control networks can implement real-time control data transceiving on the bandwidth-shared networks in a time-sliced manner, these networks are dedicated and cannot be compatible with the ordinary ethernet (such as an office network), that is, they cannot perform transceiving of information data (IT) while transceiving control data (OT traffic).

In the aspect of power supply, the ethernet has been developed for many years to form a POE power supply technology, which can transmit electric energy over 4 pairs of twisted pairs to supply power to network cable end equipment without a power line, but as mentioned above, 4 pairs of twisted pairs still cannot meet the requirements in some fields.

Therefore, in the field of distributed real-time control networks, a network technology that is capable of carrying by a single twisted pair, realizing hybrid transmission of control and information data, and having a double-wire power supply capability is needed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a single-twisted-pair TSN passive coupler and a design method thereof, which are used for solving the problem of interconnection of distributed time-sensitive network nodes.

In order to solve the technical problems, the invention adopts the following technical scheme:

a design method of a single-twisted-pair TSN passive coupler comprises the following steps:

step one, realizing the double-wire Ethernet communication;

step two, realizing power supply of the double-wire Ethernet;

thirdly, power supply relay access;

step four, three-port TSN exchange is realized;

step five, the compatibility to the common Ethernet interface;

step six, establishing a time scheduling mechanism based on gating;

dividing the data priority;

eighthly, implementing multi-node hybrid networking;

and step nine, realizing centralized network configuration.

Specifically, the method comprises the following steps:

step one, realizing the two-wire Ethernet communication:

the double-wire circuit is designed to realize the double-wire Ethernet communication, and the design steps of the double-wire circuit are as follows:

step S11, using the two-wire PHY chip and the 3-port TSN exchange chip to interconnect, the interconnect is divided into data interconnect and control interconnect; the data interconnection is used for realizing high-speed network data communication; the control interconnection uses a low-speed interface for realizing the configuration of physical layer parameters;

step S12, before the signal is transmitted to the double-wire through the connector, the signal needs to be isolated and interference eliminated through a transformer;

step two, realizing power supply of the double-wire Ethernet:

the double-line power supply device is arranged between the transformer and the double-line network connector and is divided into a power supply device and an isolation device;

the power supply device is used for supplying power from one node to another node and comprises a power supply, a power supply end, a power receiving end and a load;

the isolating device is used for isolating the signal from the power supply and ensuring that the signal and the power supply can be transmitted in the same medium; the isolation device comprises an isolation transformer, a capacitor and an inductor;

step three, power supply relay access:

when the power supply relays are connected, in order to avoid conflict between a power supply of a superior coupler and a relay power supply, a posterior power supply control circuit is designed on each coupler, and the power supply to the posterior is disconnected by using a change-over switch;

step four, realizing three-port TSN exchange:

in a long-distance distributed control system, nodes are directly interconnected, and a network device with a three-port switching function is needed to realize the function of interconnection among the nodes, wherein the three ports are a P1 port, a P2 port and a P3 port respectively; the 2 ports are respectively used for uplink communication and downlink communication, and the 3 rd port is used for providing an interface for equipment to be accessed into a network;

step five, the compatibility of the common Ethernet interface is as follows:

2 physical interfaces are designed on a P3 port, one physical interface is a double-wire interface and is used for connecting double-wire equipment, and the other physical interface is a common Ethernet 8-wire interface and is used for realizing that common equipment is connected to the distributed network;

step six, establishing a time scheduling mechanism based on gating:

establishing a time scheduling mechanism based on gating for the switching output ports, shaping network flow, designing 8 queues for each switching port, and marking as Q0-Q7, wherein the authority of the 8 queues for sending data is controlled by one gating switch, when the gating switch is opened, the queues can send data, and when the gating switch is closed, the queues can send data;

common Ethernet data is sent by using Q0, and key data for real-time control is sent by using Q7, so that hybrid transmission of non-service data can be realized;

step seven, dividing the data priority:

among the 8 queues, Q7 is set as the highest priority queue, and Q0 is the lowest priority queue;

step eight, implementing multi-node hybrid networking:

when a multi-node is networked, the couplers are interconnected end to end by using double lines, namely a P1 port and a P2 port are used, a communication node to be accessed to the network is accessed through a P3 port, and the multi-node is a double-line node or a common 8-line network node;

step nine, realizing centralized network configuration:

the centralized network configuration mode is as follows:

the method comprises the steps that a configuration computer accesses a network by using a coupler, carries out network planning according to actual application requirements, generates a configuration file, and then provides the network to send the configuration file to each node, wherein the configuration file comprises information such as gating opening time, gating scheduling table, message priority of each node, whether power is supplied to a later stage or not;

after receiving the configuration file and correctly configuring the parameters of the nodes, the nodes return state information to the configuration computer, the configuration computer confirms whether each node is correctly configured or not according to the returned state, and after the configuration is finished, the configuration computer quits the network, and each network node can operate by itself.

The invention also has the following technical characteristics:

in the second step, the isolation transformer is used for providing the alternating current signal and blocking the direct current power supply, so that the direct current power supply only exists in the secondary coil of the transformer and the double-wire medium, the electric energy can be transmitted by the double-wire medium, the passing of the network alternating current signal is not influenced, and the network supply function on the double-wire communication medium is realized.

In the third step, the switch uses IO to access the TSN chip, and then accesses the network.

In the fourth step, the three-port TSN exchange function is realized by using an FPGA, a time synchronization function and a gating scheduling function are implemented in the FPGA, port forwarding logic is implemented, and a forwarding relation table of a communication MAC address and a port is established;

after receiving data from the P1 port, if the MAC address is not the MAC address of the device connected to the P3 port, all the data are forwarded to the P2 port, and if the MAC address is the MAC address of the device connected to the P3 port, the data are forwarded to the P3 port; after receiving the data from the P2 port and the P3 port, the same method is adopted for processing, and a three-port TSN switching function is realized.

The invention also protects a single-twisted-pair TSN passive coupler which is manufactured by adopting the design method of the single-twisted-pair TSN passive coupler.

Compared with the prior art, the invention has the following technical effects:

the coupler can realize distributed connection of TSN network nodes, the connection adopts a single twisted pair, and the communication bandwidth is 1000 Mbps. The coupler mainly comprises a single-twisted-pair Ethernet PHY chip and an FPGA chip, and the core function is realized by using the FPGA. The dual-line power supply of the coupler enables the coupler node to be passive, enables the node to be connected to a network more simply and conveniently, and reduces cables. The method is suitable for the fields of network communication and real-time control, and has the characteristics of few cables and simplicity in use.

And (II) the invention adopts the unshielded twisted pair, thereby reducing the cost. The unshielded twisted pair is used for connecting network nodes, so that the number of cables is reduced, the cost is reduced, the weight of the cables in network interconnection is reduced, the cables can be wired in a narrower space, and full-duplex network communication equivalent to that of a common gigabit network is realized.

And (III) the invention adopts passive distributed interconnection, thereby reducing the complexity of network use. The three ports are interconnected in a distributed mode, power is supplied through the twisted pair, the nodes can be connected to the coupler through the double-wire network connector to be accessed into the network, power is supplied to the nodes, extra power wires are not needed, and the use is convenient.

And (IV) the invention supports TSN and realizes control and information mixed transmission. The TSN is supported, 8 queues can distinguish different types of messages, batch data such as audio and video can be simultaneously sent while key control messages are sent, the application range is wider, and the method can be widely applied to the field of distributed real-time control.

And (V) the double-wire passive coupler designed by the design method can realize distributed wiring connection of time-sensitive network (TSN) nodes, simultaneously supplies power to the nodes, has the TSN function, can provide a data transceiving function of multi-service fusion for a system, realizes IT (information technology) and OT (operation technology) service data mixed transmission, and is very suitable for the field of distributed real-time control.

Drawings

Fig. 1 is a schematic block diagram of a passive coupler.

Fig. 2 is a schematic topology of a two wire power supply.

Fig. 3 is a schematic diagram of the two-wire power supply principle.

Fig. 4 is a schematic diagram of the power control principle of the coupler.

Fig. 5 is a compatible diagram of a general ethernet interface.

Fig. 6 is a schematic diagram of multi-node hybrid networking.

Fig. 7 is a schematic diagram of a network configuration.

The present invention will be explained in further detail with reference to examples.

Detailed Description

It is to be understood that all devices and chips of the present invention are intended to be used without specific recitation, and that such devices and chips are known in the art.

In the present invention, it is to be noted that:

TSN, Time Sensitive Networking, refers to a Time Sensitive network.

PHY, or Physical, refers to port Physical layer.

An FPGA, i.e., a Field-Programmable Gate Array, refers to a Field-Programmable Gate Array.

The MAC, i.e., Media Access Control, refers to Media Access Control.

The configuration computer, namely the network planning and the short name of the configuration computer, adopts the network planning and the configuration computer known in the field.

The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention.

Example 1:

the embodiment provides a design method of a single-twisted-pair TSN passive coupler, which comprises the following steps:

step one, realizing the two-wire Ethernet communication:

as shown in fig. 2, a two-wire circuit is designed to implement two-wire ethernet communication, and the two-wire circuit is designed as follows:

step S11, interconnecting by using a two-wire PHY chip and a 3-port TSN exchange chip, and dividing the interconnection into data interconnection and control interconnection for realizing data communication and network parameter configuration; the data interconnection is used for realizing high-speed network data communication; the control interconnection uses a low-speed interface for realizing the configuration of physical layer parameters;

in step S12, before the signal is transmitted to the two-wire through the connector, the signal needs to be isolated and interference eliminated through a transformer, so as to provide reliability for the two-wire signal transmission.

Step two, realizing power supply of the double-wire Ethernet:

after having the dual-line signal transmission capability, the dual-line power supply needs to be realized, as shown in fig. 3, the dual-line power supply device is placed between the transformer and the dual-line network connector, and the dual-line power supply device is divided into a power supply device and an isolation device;

the isolation transformer is used for providing an alternating current signal and blocking a direct current power supply, so that the direct current power supply only exists in a secondary coil and a double-wire medium of the transformer, the electric energy can be transmitted by the double-wire medium, the passing of a network alternating current signal is not influenced, and the network supply function on the double-wire communication medium is realized.

Step three, power supply relay access:

as shown in fig. 4, due to the relationship of the double wire diameters, the power supply power is limited, a power supply relay needs to be designed when multiple nodes are interconnected, when the power supply relay is connected, in order to avoid the conflict between the power supply of the superior coupler and the relay power supply, a posterior power supply control circuit is designed on each coupler, a change-over switch is used, the power supply to the posterior stage can be cut off, the switch is connected to a TSN chip through an IO (input/output) circuit and then connected to a network, and whether the coupler supplies power to the posterior stage or not can be controlled after the coupler is uniformly configured in the whole network.

Step four, realizing three-port TSN exchange:

in a long-distance distributed control system, a switch is not needed, but nodes are directly interconnected to realize the function of interconnection among the nodes, and a network device with a three-port switching function is needed, wherein the three ports are respectively a P1 port, a P2 port and a P3 port, 2 ports are respectively used for uplink communication and downlink communication, and the 3 rd port is used for providing an interface for a device to be accessed into a network.

Specifically, a three-port TSN switching function is realized by using an FPGA (field programmable gate array), a time synchronization function and a gating scheduling function are implemented in the FPGA, port forwarding logic is implemented, and a forwarding relation table of a communication MAC (media access control) address and a port is established;

Step five, the compatibility of the common Ethernet interface is as follows:

the passive coupler obtained through the steps one to four has basic functions, and can realize distributed interconnection to TSN network devices, since the TSN network itself is seamlessly compatible to the ordinary ethernet, in order to enhance compatibility, 2 physical interfaces are designed on the P3 port in this step, as shown in fig. 5, one physical interface is a two-wire interface for connecting a two-wire device (P3), and the other physical interface is an ordinary ethernet 8-wire interface (i.e., 4 pairs of twisted pairs) for realizing access of the ordinary device to the distributed network.

Step six, establishing a time scheduling mechanism based on gating:

establishing a time scheduling mechanism based on gating for the switching output ports, shaping network flow, designing 8 queues for each switching port, and marking as Q0-Q7, wherein the authority of the 8 queues for sending data is controlled by one gating switch, when the gating switch is opened, the queues can send data, and when the gating switch is closed, the queues can send data; by reasonably arranging the transmission distribution of each queue gating switch on a time axis, the data which do not pass through the queue can be transmitted to the network in a time-sharing manner, and data collision is avoided. Common Ethernet data is sent by using Q0, and key data for real-time control is sent by using Q7, so that hybrid transmission of non-service data can be realized;

step seven, dividing the data priority:

after a time scheduling mechanism based on gating is established, data on a network is shaped, collision cannot occur, however, in actual application, the Q0 data and the Q7 data are sent at the same time, at this time, priority transmission of key control data needs to be guaranteed, time certainty is provided for the key data, data priority needs to be divided, and in case of collision, data with high priority is sent preferentially.

Of the 8 queues, Q7 is set as the highest priority queue, and Q0 is the lowest priority queue (transmitting normal ethernet data).

Step eight, implementing multi-node hybrid networking:

as shown in fig. 6, in a multi-node networking, the couplers are interconnected end to end by using two wires, that is, a P1 port and a P2 port are used, and a communication node to be networked is accessed through a P3 port, wherein the multi-node is a two-wire node or a common 8-wire (4 twisted pair) network node.

Step nine, realizing centralized network configuration:

after a gating scheduling mechanism is established and data priority division is realized, each node can realize the transceiving of the information of the unavailable priority, but each node is isolated and has respective gating time slots, and the time slots of each node need to be uniformly planned in the whole network to form a configuration file when distributed control is realized, and then the configuration file is provided to the network and is issued to each node.

As shown in fig. 7, the centralized network configuration mode is as follows:

Example 2:

in this embodiment, a single-twisted pair TSN passive coupler is provided, and as shown in fig. 1, the single-twisted pair TSN passive coupler is manufactured by using the design method of the single-twisted pair TSN passive coupler in embodiment 1.

Claims

1. A design method of a single-twisted-pair TSN passive coupler is characterized by comprising the following steps:

step one, realizing the double-wire Ethernet communication;

step two, realizing power supply of the double-wire Ethernet;

thirdly, power supply relay access;

step four, three-port TSN exchange is realized;

step five, the compatibility to the common Ethernet interface;

step six, establishing a time scheduling mechanism based on gating;

dividing the data priority;

eighthly, implementing multi-node hybrid networking;

and step nine, realizing centralized network configuration.

2. The method of designing a single-twisted pair TSN passive coupler of claim 1, comprising the steps of:

step one, realizing the two-wire Ethernet communication:

step two, realizing power supply of the double-wire Ethernet:

step three, power supply relay access:

step four, realizing three-port TSN exchange:

step five, the compatibility of the common Ethernet interface is as follows:

step six, establishing a time scheduling mechanism based on gating:

step seven, dividing the data priority:

step eight, implementing multi-node hybrid networking:

step nine, realizing centralized network configuration:

the centralized network configuration mode is as follows:

3. The method for designing a single-twisted pair TSN passive coupler according to claim 2, wherein in step two, the isolation transformer is used to provide the ac signal and block the dc power supply, so that the dc power supply only exists in the secondary coil of the transformer and the bifilar medium, thereby realizing the function of network supply on the bifilar medium without affecting the passing of the network ac signal.

4. The method for designing a single-twisted pair TSN passive coupler of claim 2, wherein in step three, the switch is connected to the TSN chip by IO, and further connected to the network.

5. The design method of the single-twisted pair TSN passive coupler of claim 2, wherein in the fourth step, the three-port TSN switching function is implemented using an FPGA, a time synchronization function and a gate control scheduling function are implemented in the FPGA, a port forwarding logic is implemented, and a forwarding relation table of a communication MAC address and a port is established;

6. A single-twisted pair TSN passive coupler, characterized in that, the single-twisted pair TSN passive coupler is manufactured by the design method of the single-twisted pair TSN passive coupler of any one of claims 1 to 5.