WO2014032350A1

WO2014032350A1 - Method and node based on seamless redundant ring network for increasing precision of clock

Info

Publication number: WO2014032350A1
Application number: PCT/CN2012/082004
Authority: WO
Inventors: 黄剑超; 马化一
Original assignee: 北京东土科技股份有限公司
Priority date: 2012-08-31
Filing date: 2012-09-26
Publication date: 2014-03-06
Also published as: CN102833061B; CN102833061A

Abstract

A method and node based on a seamless redundant ring network for increasing clock precision. When synchronize clock information transmitted by an adjacent node or by a master clock is received by the node in the seamless redundant ring network, the node determines the residing duration of the synchronize clock information in the present node, where the residing duration is the length of time between a point in time that the synchronize clock information is inputted to an entry port and a point in time that the synchronize clock information is outputted to an exit port. The received synchronize clock information is revised on the basis of the determined residing duration. If the exit port is a ring port, then the revised synchronize clock information is forwarded to the adjacent node via the ring port; if the exit port is an external port, then the revised synchronize clock information is forwarded to a slave clock via the external port, thus allowing the slave clock to perform a clock synchronization on the basis of the synchronize clock information. The technical solution of the present invention solves the problem of increased synchronization error between the master and slave clocks.

Description

Method and node for improving clock precision based on seamless redundant ring network This application claims to be submitted to the Chinese Patent Office on August 31, 2012, the application number is 201210320749.5, and the invention name is

The priority of the Chinese Patent Application for "Method and Node for Improving Clock Accuracy Based on Seamless Redundant Ring Network" is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present invention relates to the field of ring networks, and in particular, to a method and a section for improving clock accuracy based on a seamless redundant ring network

BACKGROUND OF THE INVENTION In order to solve the redundancy of a network transmission path, a fast spanning tree protocol is currently used in a high availability network (Rapid

Spanning Tree Protocol (RSTP) and Multiple Spanning Tree Protocol (MSTP), see Institute of Electrical and Electronics Engineers (IEEE) 802. lw, these two protocols can be applied to loops. The network implements path redundancy through a certain algorithm, and at the same time prunes the loop network into a loop-free tree network.

Although these two protocols can detect link failures, because the operation needs to frequently send messages to check the network status, the recovery time is generally relatively long, so these two protocols do not meet the real-time requirements of industrial networks. .

In order to solve the real-time requirements of network protocols for industrial networks, the International Electrotechnical Commission (C) has developed an industrial automation high availability network protocol set IEC 62439 protocol, of which IEC 62439-2 Media Redundancy Protocol (MRP) The master-slave network structure is used, but since there is only one determined master node in the network, only the master device handles the fault when the fault occurs, so there is a problem of network risk concentration, and the redundancy of the terminal critical equipment is not realized. protection. IEC 62439-3 Parallel Redundancy Protocol (PRP) uses two fully peer-to-peer host networks. The terminal device uses dual-port redundancy technology to achieve fast fault recovery, but its dual-port health status cannot exist. The detection and system costs are doubled.

To this end, the prior art has added a high availability seamless automatic ring in IEC 62439-3 (High Availability)

The content of the protocol of the Seamless Automation Ring (HSR). The technical content of the protocol is mainly to send data frames from two ports of a node of the ring network to the ring network, and the data frames sent from one port are terminated on the other port of the node. Transmission, thereby enabling seamless transmission of data frames in a ring network. In fact, in the above HSR transmission mode, each node receives two identical data frames, thus causing a waste of transmission paths in the ring network, and fixing the redundant ports of each node also causes the nodes to be used. Waste of port resources. Based on the problems arising from IEC 62439-3, the applicant proposed a seamless redundant transmission method in the ring network, and the Around Seamless Redundancy (ASR) method. Please refer to the Chinese patent No. 201210167896.3. The technical solution in the patent application is: a node in the ring network sends a data frame to two ports located in the ring network respectively, when two data frames reach a certain node in the ring network, The node no longer forwards the data frame, that is, the data frame terminates at a node in the ring network.

The Accurate Clock Protocol (IEEE1588 protocol) implements accurate clock synchronization in measurement and control systems implemented in technologies such as network communications, local computing, and distributed objects. As shown in Figure 1, nodes 1, 2, and 3 are seamlessly redundant. The nodes in the network, 1A and 1B are the ring ports of node 1, 2A and 2B are the ring ports of node 2, 3A and 3B are the ring ports of node 3, and the external ports of node 1 are connected to the master clock of the precision clock protocol, node 3 The external port is connected to the slave clock of the precision clock protocol. In order to ensure time synchronization between the slave clock and the master and slave clocks, the master clock can send synchronous clock information to the connected node (node 1), and the node 1 carries the received synchronous clock information in the ring network message and forwards it to the adjacent node. After receiving the ring network message carrying the synchronous clock information, the node 3 forwards the synchronous clock information to the slave clock, and the slave clock performs clock synchronization according to the synchronous clock information. The existing precise clock protocol indicates that in a seamless redundant ring network, each node transmits a ring network message carrying synchronous clock information only as a transparent clock instead of a boundary clock, and each node only synchronizes clock information or carries The ring network packet with the synchronous clock information is forwarded. However, the node receives and forwards the synchronous clock information or the ring network packet carrying the synchronous clock information has a certain time delay. In order to correct the delay of the node, the prior art proposes A fixed correction value is preset, and each node uses the correction value to correct the synchronization clock information.

However, when the nodes in the seamless redundant ring network receive and forward the synchronous clock information or the ring network message carrying the synchronous clock information, the time delay is uncertain. If the fixed correction value is used to correct the synchronous clock information, It will cause a large synchronization error in the synchronization of the master and slave clocks. If the accuracy of the error is in the us level, the result will have a us-level effect on the precision of the precision clock protocol. For many clock synchronizations requiring us-level precision. Application scenarios can have a big impact. SUMMARY OF THE INVENTION In view of the above, the embodiments of the present invention provide a method and a node for improving clock precision based on a seamless redundant ring network, which are used to solve the problem in the prior art that each node receives and forwards synchronous clock information or carries a synchronous clock. The ringing of information • The time delay of the time is uncertain, which leads to a large synchronization error of the master-slave clock.

The embodiment of the invention is implemented by the following technical solutions:

A method for improving clock accuracy based on a seamless redundant ring network, including:

After receiving the synchronization clock information sent by the adjacent node or the master clock, the node in the seamless redundant ring network determines the resident duration of the received synchronization clock information in the local node, and the resident duration is synchronization. The length of time between the point in time when the clock information is input to the ingress port and the time point from the output to the egress port;

Correcting the received synchronous clock information according to the determined resident duration; If the egress port is a ring port, the modified synchronization clock information is forwarded to the adjacent node through the ring port. If the egress port is an external port, the modified synchronization clock information is forwarded to the external port. The slave clock, so that the slave clock is clocked according to the synchronous clock information.

A node in a seamless redundant ring network, including:

a receiving unit, configured to receive synchronous clock information sent by an adjacent node or a master clock;

a dwell duration determining unit, configured to determine a dwell duration of the synchronization clock information received by the receiving unit in the local node, where the dwell time is a time from the input to the ingress port to the output to the egress port Length of time between points;

a synchronous clock correcting unit, configured to correct the received synchronous clock information according to the resident duration determined by the resident duration determining unit;

a forwarding unit, configured to: when the egress port is a ring port, forward the corrected synchronization clock information to the adjacent node by using the ring port, and when the egress port is an external port, pass the external port The corrected synchronous clock information is forwarded to the slave clock so that the slave clock performs clock synchronization based on the synchronous clock information.

The method for improving the clock precision based on the seamless redundant ring network according to the present invention, because each node respectively determines the time delay of receiving and forwarding the synchronous clock information or the ring network carrying the synchronous clock information, Then, according to the determined time delay, the received synchronous clock information is corrected and then forwarded, instead of using a fixed correction value to correct the synchronous clock information, thereby effectively reducing the synchronization error of the master-slave clock and improving the master. Synchronization accuracy from the clock.

Other features and advantages of the invention will be set forth in the description which follows, and The objectives and other advantages of the invention will be realized and attained by the <RTI

The technical solutions of the present invention are further described in detail below through the accompanying drawings and specific embodiments. The drawings are intended to provide a further understanding of the invention, and are intended to be a In the drawing:

1 is a schematic structural view of a seamless redundant ring network in the prior art;

2 is a schematic flowchart of a method for improving clock precision based on a seamless redundant ring network according to Embodiment 1 of the present invention; FIG. 3 is a flowchart showing a duration of synchronization clock information in a node according to Embodiment 2 of the present invention;

4 is a schematic flowchart of clock frequency synchronization of a local clock of a node according to Embodiment 3 of the present invention; FIG. 5 is a schematic structural diagram 1 of a node in a seamless redundant ring network according to Embodiment 4 of the present invention; 5-2 is a second schematic structural diagram of a node in a seamless redundant ring network according to Embodiment 4 of the present invention;

FIG. 6 is a third schematic structural diagram of a node in a seamless redundant ring network according to Embodiment 5 of the present invention. detailed description

The preferred embodiments of the present invention are described in conjunction with the accompanying drawings, and the preferred embodiments of the present invention are intended to illustrate and explain the invention.

The structure of the seamless redundant ring network is shown in Figure 1. The seamless redundant ring network includes several nodes (node 1, node 2, and node 3 in Figure 1). Of course, the nodes included in the seamless redundant ring network are not limited to the three nodes in Figure 1, but also the chain network composed of two nodes is also called the seamless redundant ring network. Here, the seamless redundancy The ring network includes both the HSR network and the ASR network, and can also be extended to the seamless redundant ring network type not listed. Each node in the seamless redundant ring network is connected by a link.

In Figure 1, the external port of node 1 is connected to the master clock, and the external port of node 3 is connected to the slave clock. Here, which node in the seamless redundant ring network can be deployed according to the actual needs of the engineering implementation, or the master clock can be connected to the node 2 or 3 in the ring network. Of course, which node is connected from the clock can also be based on The actual needs of the project implementation are deployed. Each node (such as node 1, node 2, and node 3 in Figure 1) is connected through a ring port.

Example 1

As shown in FIG. 2, it is a flow chart of a method for improving clock precision based on a seamless redundant ring network according to Embodiment 1 of the present invention. The method includes the following steps:

Step 21: After receiving the synchronization clock information sent by the adjacent node or the master clock, the node in the seamless redundant ring network determines the resident duration of the received synchronization clock information in the local node, where the resident The duration is the length of time between the point in time when the synchronous clock information is input to the ingress port and the time point from the output to the egress port.

The synchronous clock information is transmitted between the master clock and the node, and the synchronous clock information is also transmitted between the slave clock and the node, and the ring network packets carrying the synchronous clock information are transmitted between the nodes, that is, the synchronization information is carried in the ring network report. Transfer in the text. Specifically, the master clock sends the synchronous clock information to the connected node through the external port, and the node connected to the master clock receives the synchronous clock information, and then corrects the synchronous clock information, and carries the modified synchronous clock information in the ring network message. Sending to the adjacent node, if the neighboring node receives the ring network message, it extracts the synchronous clock information from the ring network message, and corrects the synchronous clock information. If the node is not connected to the slave clock, it will be corrected. The subsequent synchronous clock information is carried in the ring network message and sent to the adjacent node. If the slave node is connected to the slave clock, the modified synchronous clock information is sent to the slave clock.

The ingress port of the node receiving the synchronous clock information may be an external port or a ring port. If the ingress port is an external port, it indicates that the node has a master clock connected through the external port, and the outbound port is a ring port, that is, the node passes through the ring. The port forwards the ring network carrying the synchronous clock information to the adjacent node; if the ingress port is a ring port, the egress port is both It can be a ring port or an external port. When the egress port is a ring port, it indicates that the node is not connected to the master clock and the slave clock. The node forwards the ring network packet carrying the synchronous clock information to the adjacent node through the ring port. When the egress port is an external port, it indicates that the node is connected to the slave clock through the external port, and the node forwards the synchronous clock information to the slave clock through the external port.

In the first embodiment of the present invention, a node connected to the master clock may be referred to as an originating node, and a node connected to the slave clock may be referred to as a receiving node, and then other nodes may be referred to as intermediate nodes. In Figure 1, node 1 is the originating node, node 3 is the receiving node, and node 2 is the intermediate node. The originating node receives the synchronous clock information sent by the master clock through the external port, and forwards the ring network message carrying the synchronous clock information to the adjacent node through the two ring ports respectively, and the intermediate node receives the sent by the neighboring node through the ring port. The ring network packet forwards the ring network packet to the neighboring node through another ring port. The receiving node receives the ring network packet sent by the neighboring node through the ring port, and forwards the synchronous clock information to the slave clock through the external port.

The duration of the synchronization clock information received by the node in the node can also be regarded as the time delay when the node receives and forwards the synchronization clock information or the ring network message carrying the synchronization information. The duration of the reservation specifically refers to the synchronization clock information. Enter the length of time between the point in time of the ingress port and the point in time when it is output to the egress port.

It should be noted that, for the originating node, the ingress port is an external port, and the originating node sends the ring network containing the synchronous clock information to the two ring ports simultaneously, that is, the egress port is two ring ports, and the synchronous clock The length of time between the input of the information to the external port and the output to one of the ring ports is the same as the length of time between the synchronization clock information from the input to the external port and the output to the other ring port.

Step 22: Correct the received synchronous clock information according to the determined resident duration.

If the node is the originating node, the received synchronous clock information is the uncorrected synchronous clock information sent by the master clock. If the node is not the originating node, the synchronous clock information carried in the received ring network message Synchronized clock information corrected for each node.

If the resident time length determined by the node is Δ Τ and the time point corresponding to the received synchronous clock information is T, the time point corresponding to the corrected synchronous clock information is T' = Δ T + T.

Step 23: If the egress port is a ring port, the modified synchronization clock information is forwarded to the adjacent node through the ring port, and if the egress port is an external port, the modified synchronization is performed through the external port. The clock information is forwarded to the slave clock so that the slave clock is clocked according to the synchronous clock information.

If the node is an originating node or an intermediate node, the egress port is a ring port. At this time, the node forwards the ring network carrying the corrected synchronization clock information to the adjacent node through the ring port.

If the node is a receiving node, the egress port is an external port, and the node forwards the corrected synchronous clock information to the slave clock through the external port. After receiving the synchronous clock information from the clock, clock synchronization is performed according to the synchronous clock information, thereby realizing clock synchronization between the slave clock and the master clock. The slave clock performs clock synchronization according to the synchronous clock information received first, and discards the subsequently received synchronous clock information. It can be seen from the above process that, in the technical solution proposed by Embodiment 1 of the present invention, after receiving the synchronization clock information sent by the adjacent node or the master clock, the node in the seamless redundant ring network determines that the received synchronous clock information is The length of the dwell time in the node, the dwell time is the length of time between the time point of the synchronous clock information from the input to the ingress port to the time point of the output to the egress port, and the node corrects the receiving according to the determined dwell time. If the outgoing port is a ring port, the node forwards the corrected synchronous clock information to the adjacent node through the ring port, and if the outgoing port is an external port, the node passes the The external port forwards the corrected synchronous clock information to the slave clock, so that the slave clock synchronizes the clock according to the synchronous clock information. Each node determines the time delay of receiving and forwarding the synchronous clock information or the ring network carrying the synchronous clock information, and then correcting the received synchronous clock information according to the determined time delay before forwarding. Instead of using a fixed correction value to correct the synchronous clock information, the synchronization error of the master-slave clock is effectively reduced, and the synchronization accuracy of the master-slave clock is improved.

Example 2

When determining the duration of the received synchronization clock information in the local node, the node may first obtain the first count value of the local clock when the synchronous clock information is input to the ingress port, and when the synchronous clock information is output to the egress port, the local The second count value of the clock is then determined according to the obtained first count value and second count value, and the clock frequency of the local clock, the duration of the synchronization clock information in the local node. The local clock in the node is counted according to its own clock frequency.

The time point at which the node receives the synchronous clock information from the ingress port is Τ 1, and the time point at which the synchronous clock information is output to the egress port is Τ2. As shown in FIG. 3, the duration of the synchronization clock information in the node is Δ. Τ=Τ2-Τ1.

When the node is an originating node, the time point at which the node receives the synchronous clock information from the external port is Τ1, the time at which the synchronous clock information is output to the ring port is Τ2, and the clock frequency of the local clock of the node is 125M, that is, The count is performed every 8 ns. When the synchronous clock information is input to the external port, the first count value of the local clock is nl. When the synchronous clock information is output to the ring port, the second count value of the local clock is n2, then Tl=nl*8 , Τ2=η2*8, the duration of the synchronization clock information in this node is Δ Τ=Τ2-Τ1.

When the node is an intermediate node, the time point at which the node receives the ring network message carrying the synchronous clock information from the first ring port is T1, and the time point at which the synchronous clock information is output to the second ring port is Τ2, the node The clock frequency of the local clock is 125 M, that is, every 8 ns is counted. When the ring network packet carrying the synchronous clock information is input to the first ring port, the first count value of the local clock is nl, and the synchronous clock information is output to the second. When the ring port is used, the second count value of the local clock is n2, then Tl=nl*8, Τ2=η2*8, and the duration of the synchronization clock information in the node is Δ Τ=Τ2-Τ1.

When the node is a receiving node, the time point at which the node receives the ring network message carrying the synchronous clock information from the ring port is T1, and the time point at which the synchronous clock information is output to the external port is Τ2, the clock of the local clock of the node Frequency is

125M, that is, counting every 8 ns, when the ring network carrying the synchronous clock information is input to the ring port, the first count value of the local clock is nl, and when the synchronous clock information is output to the external port, the second of the local clock The count value is n2, then

Tl=nl*8, Τ2=η2*8, the duration of the synchronization clock information in the node is Δ Τ=Τ2-Τ1. Example 3

It can be seen from the second embodiment that the node determines the duration of the synchronization clock information in the local node according to the clock frequency of the local clock. To ensure that the clock frequency of the local clock of each node is consistent with the clock frequency of the master clock, Embodiment 3 of the present invention It is proposed that each node can synchronize the clock frequency of the local clock before determining the resident duration. The method flow is shown in FIG. 4, and the specific processing flow is:

Step 41: Determine a deviation of a clock frequency between the local clock and the main clock according to the synchronous clock information received this time and the synchronous clock information received last time.

The master clock can periodically send synchronous clock information.

Step 42: Synchronize the clock frequency of the local clock according to the determined deviation of the clock frequency.

Specifically, the node may first determine the time point corresponding to the synchronous clock information received this time, the time point corresponding to the last received synchronous clock information, the time point of receiving the synchronous clock information, and the last time receiving the synchronous clock information. At the time point, then based on the determined time points, the deviation of the clock frequency between the local clock and the main clock is calculated.

If Δ is the deviation of the clock frequency between the local clock and the main clock, t2 is the time point corresponding to the received synchronous clock information, and tl is the time point corresponding to the last received synchronous clock information, t2' For the time when the synchronous clock information is received, tl' is the time point when the synchronous clock information is received last time, and the deviation of the clock frequency between the local clock and the master clock is:

△ =[ ( ΐ2' -tl' ) - ( t2-tl ) ]/(tl' -tl)

In the third embodiment of the present invention, after receiving the synchronization clock information, the node may record the timestamp corresponding to the time point when the inbound port receives the synchronization clock information, and then the node may directly receive the synchronization clock information according to the current time. The timestamp of the record, the time point at which the synchronization clock information is received this time, and the time point recorded when the synchronization clock information was last received, determines the time point at which the synchronization clock information was last received.

The method for synchronizing the clock frequency of the local clock proposed in Embodiment 3 of the present invention can realize that the clock frequencies of the local clocks of all the nodes in the seamless redundant ring network are synchronized (both with the clock frequency of the main clock) Therefore, the accuracy of the resident duration calculated by each node is effectively improved, and the synchronization precision of the master-slave clock is further improved.

In addition, in Embodiment 3 of the present invention, each node periodically receives the synchronization clock information, and each time the synchronization clock information is received, not only the determination of the resident duration but also the correction of the synchronization clock information according to the resident duration is performed. Operation, but also to perform the operation of synchronizing the clock frequency of the local clock (except for the first time receiving the synchronous clock information), then the node can determine the resident according to the synchronized clock frequency after receiving the synchronous clock information next time. duration.

Example 4

The embodiment of the present invention provides that the node in the seamless redundant ring network includes the first CPU component, the second CPU component, the first ring port, and the second ring port, as shown in FIG. 5-1, where the first CPU The component is connected to the first ring port and the second ring port, and the first ring port and the second ring port are responsible for sending, receiving, and forwarding the ring network. As shown in FIG. 5-2, the first CPU component includes a packet forwarding module and a frequency synchronization module, and the second CPU component includes a protocol processing module. among them:

The packet forwarding module receives and forwards the synchronization information or the ring network message carrying the synchronization information through the external port or the ring port, and determines the resident duration of the received synchronization clock information in the node, and according to the determined resident duration. , Correct the received synchronous clock information.

The protocol processing module is configured to process the ring network and calculate the deviation of the clock frequency between the local clock and the main clock, and then send the deviation of the clock frequency to the first CPU component, and synchronize the frequency in the first CPU component. The module adjusts the clock frequency of the local clock.

The frequency synchronization module is configured to generate a local clock, and adjust the clock frequency of the local clock according to the deviation of the clock frequency provided by the protocol processing module, so that the local clock and the clock frequency of the main clock are synchronized.

In the seamless redundant ring network, the first CPU component of the node saves the time when the ingress port receives the synchronous clock information or the ring network message carrying the synchronous clock information, and the first CPU component saves the synchronous clock information to the outbound The time of the port, so that the duration of the dwell is determined based on the two times saved. For example, in FIG. 1, node 1 is an originating node, and a master clock connected to an external port of node 1 transmits synchronous clock information, and a first CPU component of node 1 stores a time at which the node receives the synchronous clock information from an external port. The first CPU component of node 1 saves the time t2 at which the synchronous clock information is transmitted to its first ring port and the second ring port, and then subtracts t2 from the recorded t2 to be the resident time of the synchronous clock information in node 1. It should be noted that the first CPU component adds the corrected synchronization clock information to the ring network message for forwarding.

Example 5

The method for improving the clock precision based on the seamless redundant ring network according to the embodiment 1 of the present invention provides a node in the seamless redundant ring network, and the structure thereof is as shown in FIG. 6, which includes:

The receiving unit 61 is configured to receive synchronous clock information sent by an adjacent node or a master clock;

The resident duration determining unit 62 is configured to determine a duration of the synchronization clock information received by the receiving unit 61 in the local node, where the resident duration is a time point from the input to the ingress port to the output to the egress port. Length of time between points in time;

The synchronization clock correction unit 63 is configured to correct the received synchronization clock information according to the resident duration determined by the resident duration determining unit 62;

The forwarding unit 64 is configured to: when the egress port is a ring port, forward the corrected synchronization clock information to the adjacent node by using the ring port, and when the egress port is an external port, pass the external port The corrected synchronous clock information is forwarded to the slave clock so that the slave clock performs clock synchronization based on the synchronous clock information.

The receiving unit 61 is not only used to receive the synchronization clock information sent by the adjacent node or the master clock, but also can be used to receive the 艮艮 text through the external port and the ring port, and the received 艮艮可以 can be the ring network · ί艮文, can also be used for other data.

The forwarding unit 64 is not only used to forward the synchronous clock information, but also can be used to forward the data through the external port and the ring port, and the forwarded message can be a ring network message or other data message. Preferably, the receiving unit 61 is configured to receive a ring network message that is sent by the neighboring node and that carries the synchronous clock information, and confirm the synchronous clock information carried in the received ring network message as an adjacent node. Synchronized clock information sent;

The forwarding unit 64 is configured to carry the modified synchronization clock information in the ring network, and forward the ring network carrying the corrected synchronization clock information to the adjacent node through the ring port.

Preferably, the resident duration determining unit 62 specifically includes:

The count value obtaining sub-unit is configured to obtain a first count value of the local clock when the synchronous clock information is input to the ingress port, and a second count value of the local clock when the synchronous clock information is output to the egress port;

The dwell duration determining subunit is configured to obtain a first count value and a second count value obtained by the subunit according to the count value, and a clock frequency of the local clock, and determine a dwell duration of the synchronous clock information in the node.

More preferably, the master clock periodically sends synchronous clock information;

The nodes in the seamless redundant ring network further include:

The clock frequency deviation determining unit is configured to: before the resident duration determining unit 62 determines the resident synchronization clock information in the local node, according to the currently received synchronous clock information and the last received synchronous clock information. Determining a deviation of a clock frequency between the local clock and the master clock;

The clock frequency synchronization unit is configured to determine a deviation of the clock frequency determined by the occupancy clock frequency deviation determining unit and synchronize the clock frequency of the local clock.

More preferably, the clock frequency deviation determining unit specifically includes:

a time point determining subunit, configured to determine a time point corresponding to the synchronous clock information received this time, a time point corresponding to the last received synchronous clock information, a time point of receiving the synchronous clock information, and a last received synchronous clock Time point of information;

The clock frequency deviation determining subunit is configured to calculate a deviation of a clock frequency between the local clock and the main clock according to each time point determined by the time point determining subunit.

More preferably, the nodes in the seamless redundant ring network further include:

a timestamp recording unit, configured to: before the clock frequency deviation determining unit determines the deviation of the clock frequency between the local clock and the main clock, after receiving the synchronous clock information, record the time point at which the ingress port receives the synchronous clock information Corresponding timestamp;

The time point determining subunit is specifically configured to determine, according to the timestamp recorded by the timestamp recording unit when the synchronous clock information is received, the time point of receiving the synchronous clock information, and according to the last time the synchronous clock information is received. The timestamp records the timestamp recorded by the unit to determine the point in time when the synchronous clock information was last received.

The receiving unit 61, the resident duration determining unit 62, the synchronous clock correcting unit 63, the forwarding unit 64, and the first

Corresponding to the packet forwarding module in the CPU component, the clock frequency deviation determining unit corresponds to the protocol processing module in the second CPU component, and the clock frequency synchronization unit corresponds to the frequency synchronization module in the first CPU component. Those skilled in the art will appreciate that embodiments of the present application can be provided as a method, apparatus (device), or computer program product. Thus, the application can be in the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the application can be in the form of a computer program product embodied on one or more computer-usable storage interfaces (including but not limited to disk storage, CD-ROM, optical storage, etc.) in which computer usable program code is embodied.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments of the present application. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

Although the preferred embodiment of the present application has been described, those skilled in the art can make additional changes and modifications to the embodiments once they are aware of the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and It will be apparent that those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the application. Accordingly, it is intended that the present invention cover the modifications and variations of the present invention.

Claims

Rights request

1. A method to improve clock accuracy based on a seamless redundant ring network, which is characterized by:

After receiving the synchronization clock information sent by the adjacent node or the master clock, the node in the seamless redundant ring network determines the residence time of the received synchronization clock information in the node, and the residence time is synchronization The length of time between the time point when the clock information is input to the inlet port and the time point when it is output to the egress port;

Correct the received synchronization clock information according to the determined dwell time;

If the outgoing port is a ring port, then the corrected synchronization clock information is forwarded to the adjacent node through the ring port. If the outgoing port is an external port, then the corrected synchronization clock information is forwarded to the adjacent node through the external port. Slave clock, so that the slave clock is clock synchronized based on the synchronized clock information.

2. The method for improving clock accuracy based on a seamless redundant ring network according to claim 1, characterized in that determining the residence time of the received synchronized clock information in the node specifically includes:

Obtain the first count value of the local clock when the synchronous clock information is input to the ingress port, and the second count value of the local clock when the synchronous clock information is output to the egress port;

According to the obtained first count value and second count value and the clock frequency of the local clock, the residence time of the synchronized clock information in the local node is determined.

3. The method for improving clock accuracy based on a seamless redundant ring network according to claim 2, characterized in that the master clock periodically sends synchronized clock information;

Before determining the residence time of the received synchronization clock information in the current node, the method further includes:

Determine the clock frequency deviation between the local clock and the master clock based on the synchronous clock information received this time and the synchronous clock information received last time;

Based on the determined deviation of the clock frequency, the clock frequency of the local clock is synchronized.

4. The method for improving clock accuracy based on seamless redundant ring network according to claim 3, characterized in that, based on the synchronization clock information received this time and the synchronization clock information received last time, it is determined that the local clock and The clock frequency deviation between the main clocks specifically includes:

The node determines the time point corresponding to the synchronization clock information received this time, the time point corresponding to the synchronization clock information received last time, the time point when the synchronization clock information is received this time, and the time point when the synchronization clock information was last received; According to each determined time point, the clock frequency deviation between the local clock and the master clock is calculated.

5. The method for improving clock accuracy based on a seamless redundant ring network according to claim 4, characterized in that before determining the clock frequency deviation between the local clock and the master clock, it further includes:

After receiving the synchronous clock information, the node records the timestamp corresponding to the time point when the incoming port receives the synchronous clock information; The node determines the time point at which the synchronization clock information is received this time and the time point at which the synchronization clock information was last received, specifically including:

The node determines the time point of receiving the synchronized clock information this time based on the timestamp recorded when it receives the synchronized clock information this time, and determines the last time it received the synchronized clock information based on the timestamp recorded when it received the synchronized clock information last time. time point.

6. A node in a seamless redundant ring network, characterized by: including:

The receiving unit is used to receive the synchronization clock information sent by the adjacent node or the master clock;

The residence time determination unit is used to determine the residence time of the synchronous clock information received by the receiving unit in the node. The residence time is the time from the time when the synchronous clock information is input to the inlet port to the time when the synchronous clock information is output to the egress port. the length of time between points;

A synchronization clock correction unit, configured to correct the received synchronization clock information according to the residence time determined by the residence time determination unit;

A forwarding unit configured to forward the corrected synchronization clock information to adjacent nodes through the ring port when the outgoing port is a ring port, and when the outgoing port is an external port, forward the corrected synchronization clock information through the external port. The corrected synchronization clock information is forwarded to the slave clock, so that the slave clock performs clock synchronization based on the synchronization clock information.

7. The node in the seamless redundant ring network according to claim 6, characterized in that the residence time determination unit specifically includes:

The count value acquisition subunit is used to obtain the first count value of the local clock when the synchronous clock information is input to the ingress port, and the second count value of the local clock when the synchronous clock information is output to the egress port;

The residence duration determination subunit is used to determine the residence duration of the synchronized clock information in the node based on the first count value and the second count value obtained by the count value acquisition subunit and the clock frequency of the local clock.

8. The node in the seamless redundant ring network according to claim 7, characterized in that the master clock periodically sends synchronization clock information;

The nodes in the seamless redundant ring network also include:

The clock frequency deviation determination unit is used to determine the residence time of the received synchronization clock information in the node before the residence time determination unit determines the residence time of the received synchronization clock information in the node. According to the synchronization clock information received this time and the synchronization clock information received last time, determining a clock frequency deviation between the local clock and said master clock;

The clock frequency synchronization unit is used to synchronize the clock frequency of the local clock based on the deviation of the clock frequency determined by the clock frequency deviation determination unit.

9. The node in the seamless redundant ring network according to claim 8, characterized in that the clock frequency deviation determination unit specifically includes:

The time point determination subunit is used to determine the time point corresponding to the synchronization clock information received this time, the time point corresponding to the synchronization clock information received last time, the time point corresponding to the synchronization clock information received this time and the last time the synchronization clock was received. The time point of the information;

The clock frequency deviation determination subunit is used to calculate the clock frequency deviation between the local clock and the master clock based on each time point determined by the time point determination subunit.

10. Nodes in the seamless redundant ring network according to claim 9, characterized in that, the nodes in the seamless redundant ring network further include:

A timestamp recording unit, configured to record the time point at which the incoming port receives the synchronized clock information after receiving the synchronized clock information before the clock frequency deviation determining unit determines the clock frequency deviation between the local clock and the master clock. The corresponding timestamp;

The time point determination subunit is specifically used to determine the time point when the synchronization clock information is received this time based on the timestamp recorded by the timestamp recording unit when the synchronization clock information is received this time, and based on the time when the synchronization clock information was received last time. The timestamp recorded by the timestamp recording unit determines the time point when synchronized clock information was last received.