CN111726288B - Real-time data transmission and recovery method and system for power secondary equipment - Google Patents
Real-time data transmission and recovery method and system for power secondary equipment Download PDFInfo
- Publication number
- CN111726288B CN111726288B CN202010585954.9A CN202010585954A CN111726288B CN 111726288 B CN111726288 B CN 111726288B CN 202010585954 A CN202010585954 A CN 202010585954A CN 111726288 B CN111726288 B CN 111726288B
- Authority
- CN
- China
- Prior art keywords
- data
- frame
- link layer
- frames
- recovery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/22—Alternate routing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0061—Error detection codes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/28—Routing or path finding of packets in data switching networks using route fault recovery
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L67/00—Network arrangements or protocols for supporting network services or applications
- H04L67/01—Protocols
- H04L67/12—Protocols specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
Abstract
The invention discloses a real-time data transmission and recovery method and a system of electric power secondary equipment. By means of the non-delay fault data recovery technology based on the abnormal sequence transmission and redundant channel data transmission technology and the non-delay fault data recovery technology based on the index information, the method can perform non-delay recovery of data in a certain fault range when communication in or among the power secondary equipment is abnormal due to instantaneous electromagnetic interference or other reasons, robustness of real-time data communication is improved, and requirements of the power secondary equipment on reliability and real-time performance of the data communication are met.
Description
Technical Field
The invention relates to a data transmission method, in particular to a real-time data transmission and recovery method for electric power secondary equipment.
Background
In the power secondary equipment which has been basically realized as a microcomputer, data exchange is required to realize data sharing and resource sharing in the equipment and between the equipments, and information exchange between boards and between devices of the new generation power secondary equipment represented by the fully digital relay protection device is basically realized by real-time data communication. The real-time data communication technology has become a key basic technology for normal operation of the current power secondary equipment.
In the actual operation process, because of hardware failure or the influence of a severe external electromagnetic environment interference signal, single-bit or multi-bit data errors inevitably occur in the real-time data communication process, and communication abnormity occurs. The abnormal communication of important real-time data may cause the device to fail to work normally, even cause the device to be locked, and seriously affect the safety and quality of a power grid, so that a real-time communication channel of the power secondary equipment must have certain robustness, and the equipment can be ensured to run with high reliability and high quality.
In the current power secondary equipment, a message retransmission mechanism similar to that in ethernet transmission is mostly adopted in a general communication anomaly processing technology for important real-time data, and when a receiving end detects that a communication data frame is abnormal, the receiving end can inform a sending end of retransmitting the data frame until a receiving end obtains correct data. The method is simple in implementation mode, can better solve the problem of data probabilistic deficiency or abnormity, but has a series of inevitable defects:
(1) retransmitting a data frame results in a data delay that is several times longer than under normal conditions. The real-time data communication technology adopting the mechanism cannot meet the application requirement with higher real-time requirement;
(2) the communication reliability of the mode depends on the communication quality of a single data channel;
(3) this approach relies on a closed loop bi-directional communication system and is not suitable for unidirectional data channels.
Therefore, it is necessary to provide a new technical solution to solve the above technical problems.
Disclosure of Invention
The purpose of the invention is as follows: in order to solve the problems, the invention provides a real-time data transmission and recovery method for power secondary equipment, which is suitable for power secondary equipment such as a relay protection device and the like, and can carry out non-delay recovery of data in a certain fault range when communication in the power secondary equipment or among the power equipment is abnormal due to instantaneous electromagnetic interference or other reasons through an abnormal sequence transmission and redundant channel data transmission technology and a non-delay fault data recovery technology based on index information, so that the robustness of real-time data communication is improved, and the requirements of the power secondary equipment on the reliability and the real-time performance of the data communication are met.
The invention also provides a system corresponding to the real-time data transmission and recovery method.
The technical scheme is as follows: in order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows: a real-time data transmission and recovery method for power secondary equipment comprises the steps of providing a data block, a frame recombination module and a redundant transmission channel of a link layer of a sending end, and providing a data error detection module, a data recovery module and a frame recovery module of a frame receiving end; the sending end carries out data block recombination on a single data frame into two frames of data with different sequences through a data block and frame recombination module positioned on a link layer, and then transmits the two frames of data with different sequences to a frame receiving end through a redundant channel; the frame receiving end carries out error detection, switching and restoration on the received two frames of data with different sequences through a data error detection module, a data restoration module and a frame restoration module which are positioned on a link layer, recombines and restores the two frames of data into a single data frame and transmits the single data frame to the link layer.
Furthermore, the data is partitioned into blocks, and the frame reassembly module divides an application frame (APDU) of a single data frame into a plurality of data blocks containing length and independent check information, reassembles two frames in different sequence, and simultaneously transmits the data blocks through a redundant transmission channel.
Step one, after a data partitioning module receives a link layer interface frame message, caching the link layer frame message, and dividing APDUs therein into M packets according to the length, wherein the M calculation principle is as follows:
(1)M≥4，
(2)
wherein R isbFor message transmission rate, Δ TdThe difference between the delay required by the system and the transmission delay of the frame message, wherein N is the total length of information bytes added to a single data block when the data is blocked;
secondly, the frame recombination module adds sequence number index information and independent check information to each data block and then sorts the data blocks according to a specific sequence;
thirdly, the frame recombination module recalculates the characteristic information such as the frame length and the like according to the original data frame link layer protocol and then performs frame recombination;
step four, the redundant channels are sent simultaneously;
furthermore, any data block of two frames of out-of-sequence data is transmitted simultaneously in the redundant channel, and the difference between the sequence numbers is at least 2; for the case of dividing into 4 data blocks, if the numbers of the data blocks after the frame division are N1, N2, N3 and N4, and the transmission sequence of one channel in the redundant channel is N1, N2, N3 and N4, the transmission sequence of the other channel is N3, N4, N1 and N2. All data blocks are then recombined into new APDUs according to this order.
Furthermore, the data error detection, data recovery and frame recovery module can complete the fault recovery without delay under the conditions that any single channel has permanent fault and any single or two adjacent data blocks have errors simultaneously in the two channels. The method comprises the following specific steps:
step one, receiving messages transmitted by a redundant channel, transmitting the messages to a link layer through a physical layer, and setting a receiving buffer area.
And step two, analyzing the frame messages cached by the redundant channel, checking the data blocks in sequence, and storing the checking result.
And step three, simultaneously judging the data block check result of the redundant channel, if the data block check result passes, putting the corresponding data block into a message recovery buffer area, otherwise, searching the check result of the data block corresponding to the redundant channel according to the serial number of the data block, if the data block check result passes, and putting the data block into a message recombination buffer area.
Step four, if all data blocks of the redundant channel fail to be checked, setting a channel abnormal alarm;
and step five, after all the blocks are checked, after characteristic information such as the length of each data block is removed, frame characteristic information is recalculated, and framing is carried out to a link layer message interface.
Has the advantages that: the technical advantages of the invention are as follows:
(1) according to the method, through a redundant channel transmission mode, normal transmission of real-time data can be still guaranteed when a data block of any single channel is abnormal or a hardware link fails, and the communication reliability is improved;
(2) the method adopts an out-of-order transmission mode and a non-delay fault data recovery technology based on index information, can realize normal transmission of real-time data when any single data block of double channels is abnormal or any two adjacent data blocks are abnormal at the same time, and obviously improves the communication fault-tolerant capability.
The invention also provides a real-time data transmission and recovery system of the power secondary equipment corresponding to the data transmission and recovery method, which comprises a data blocking and frame recombining module of a link layer of a sending end, wherein the data blocking and frame recombining module is positioned on the link layer and is used for carrying out data blocking and recombining on a single data frame into two paths of data;
the data error detection, data restoration and frame recovery module of the frame receiving end is used for carrying out error detection, switching and restoration on the two paths of received data, recombining and recovering the two paths of received data into a single data frame and transmitting the single data frame to the link layer;
and the redundant transmission channel is used for transmitting the two paths of data which are recombined in blocks to a data error detection module, a data recovery module and a frame recovery module of a frame receiving end.
Drawings
FIG. 1 is a schematic diagram of a data interleaving transmission and recovery method according to the present invention;
FIG. 2 is a block diagram of a frame reassembly module according to the present invention;
FIG. 3 is a schematic diagram of restoration of fault frame data according to the present invention;
fig. 4 shows the link layer protocol and physical layer definitions of the original communication in the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1, the method for transmitting and recovering real-time data of power secondary equipment according to the present invention provides a data blocking and frame reassembly module at a transmitting end, a hardware redundancy main and standby transmission channels, and a data error detection, data recovery and frame recovery module at a receiving end. The real-time data message frame is divided into data blocks by the data blocking and frame recombining module positioned at the link layer, is re-framed and then is transmitted to the data error detection, data recovery and frame recovery module positioned at the link layer of the receiving end by the redundant hardware channel, and after the received two paths of data are subjected to error detection and recovery, the real-time data message frame is re-framed into a real-time data message frame and is transmitted.
The data block and frame recombination module at the sending end, the hardware redundancy main and standby transmission channels, and the data error detection, data restoration and frame restoration module at the receiving end also form a system adopted corresponding to the real-time data transmission and restoration method.
In one embodiment of the invention, the method is implemented in communication between board level controllers. As shown in fig. 4, the communication mode is designed as synchronous serial communication, and the physical layer transmission signals include FRM, CLK, and DATA, where FRM is used as the frame valid signal and CLK and DATA are used as the source synchronous DATA. The data interface rate of the buffer zone of the link layer is 250Mbps, the total length of messages of the link layer is 66 bytes, the length of an application frame is 60 bytes, the transmission rate is 25Mbps, and the transmission delay of the messages is 21.1 us. The application adopting the communication mode requires that the maximum delay requirement of message transmission between controllers is not more than 25 us.
In this embodiment, the frame reassembly module divides an application frame (APDU) of a serial data frame into 4 data blocks containing length and independent check information and retransmits the data blocks, which specifically includes the steps of:
step one, 3 buffer areas are arranged on a link layer, wherein one buffer area is a link layer message buffer area, and the other buffer area is a redundant channel sending buffer area. After the link layer message is valid, dividing the APDU frame into M-4 packets according to each 16 bytes, wherein the M calculation method is as follows:
(1)M≥4，
(2)
wherein Δ Td＝3.9us，Rb＝25Mbps，N＝2。
Step two, adding sequentially increasing sequence number index information and CRC check information for each data block, wherein the optional generating polynomial in CRC calculation is as follows:
CRC-8：X8+X6+X4+X3+X2+X1
step three, as shown in fig. 2, re-framing the 4 data blocks into main APDU frames and standby APDU frames and storing the main APDU frames and the standby APDU frames in the corresponding buffer areas, where the main APDU frame sequence is N1, N2, N3, N4, and the standby APDU frame sequence is N3, N4, N1, N2, that is, any data block transmitted by the main channel and the standby channel is guaranteed not to be in the corresponding or adjacent position;
recalculating characteristic information such as frame length and the like according to an original data frame link layer protocol, and storing the characteristic information into a redundant channel sending buffer area;
step five, enabling the redundant channels to transmit at the same time;
further, the data error detection, data recovery and frame recovery module performs error detection and recovery on the two paths of received data, and then re-frames the received data into a real-time data message frame and transmits the real-time data message frame. The method comprises the following specific steps:
step one, three buffers are set, two redundant receiving buffers (M0, M1) store the current received message, and one link layer buffer stores the recovered link layer frame message.
And step two, setting two checking tables T0 and T1 to store the checking result of the redundant channel. And when receiving the message, carrying out CRC (cyclic redundancy check) on the APDU data block in a pipeline mode, wherein the pass is 0, and the failure is 1. And storing the check result in T0 and T1 according to the sequence number of the data block after calculation.
Step three, carrying out fault data restoration: after the completion of the reception verification, the verification result of each block in T0 is judged.
If the value is 0, removing additional information such as sequence number, length, verification and the like from the data block corresponding to the verification result in the M0, and storing the data block in a corresponding position in the M2;
if the result is 1, the check result corresponding to the block in T1 is determined. If the data block is 0, the additional information of the corresponding data block in M1 is removed and the data block is stored in the corresponding position in M2; if the number is 1, setting a channel abnormal alarm.
If all the data in T0 or T1 are 1, setting a channel abnormal alarm;
and step five, after all the error detection and recovery of the data blocks are finished, recalculating the characteristic information such as the frame length and the like, and then framing and storing the data blocks into a link layer receiving buffer M2.
The effect achieved by the method is analyzed in this example:
(1) the failure of any single hardware channel or interference signals affecting a single hardware channel will not affect the normal transmission of data.
(2) As shown in the figure, when the single or adjacent two data blocks of the redundant channel are abnormal due to any reason, the normal transmission of the data is not influenced.
(3) After the method is adopted in the edge-group edge-sending mode, the following delay links are added: sending waiting delay, data blocking, frame recombination delay and message transmission delay. Wherein the transmission latency is 1.1us (waiting for N3 data block padding to complete); the data blocking and frame recombination module is realized in parallel by adopting programmable logic gate array (FPGA) hardware, and the time delay can be ignored; the message transmission delay increases by 2.56us due to the increased length. According to the analysis, the final communication transmission delay is 24.76us after the method is adopted. Compared with a message retransmission mode, the method can meet the requirement of the maximum 25us communication transmission delay of the system.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (1)
1. A real-time data transmission and recovery method of electric power secondary equipment is characterized in that a data block, a frame recombination module and a redundant transmission channel of a link layer of a sending end are provided, and a data error detection module, a data recovery module and a frame recovery module of a frame receiving end are provided; the sending end carries out data block recombination on a single data frame into two frames of data with different sequences through a data block and frame recombination module positioned on a link layer, and then transmits the two frames of data with different sequences to a frame receiving end through a redundant channel; the frame receiving end carries out error detection and restoration on the received two frames of data with different sequences through a data error detection module, a data restoration module and a frame restoration module which are positioned on a link layer, recombines and restores the two frames of data into a single data frame and transmits the single data frame to the link layer;
the frame recombination module divides APDU of serial data frame into 4 data blocks containing length and independent check information and then retransmits the data blocks, and the specific steps are as follows:
step 1.1, 3 buffer areas are arranged on a link layer, wherein one buffer area is a link layer message buffer area, and the other buffer area is a redundant channel sending buffer area; after the link layer message is valid, dividing an APDU frame into M =4 packets according to each 16 bytes;
step 1.2, adding sequentially increasing serial number index information and CRC (cyclic redundancy check) check information for each data block;
step 1.3, framing 4 data blocks again into main APDU frames and standby APDU frames and storing the main APDU frames and the standby APDU frames in a corresponding buffer area, wherein the main APDU frame sequence is N1, N2, N3 and N4, and the standby APDU frame sequence is N3, N4, N1 and N2, namely, any data block transmitted by a main channel and a standby channel is guaranteed not to be in a corresponding or adjacent position;
step 1.4, recalculating characteristic information such as frame length and the like according to an original data frame link layer protocol, and storing the characteristic information into a redundant channel sending buffer area;
the data error detection, data recovery and frame recovery module performs error detection and recovery on the received two frames of data, and then re-frames the two frames of data into a real-time data message frame and transmits the real-time data message frame; the method comprises the following specific steps:
step 2.1, three buffers are set, two redundant receiving buffers (M0, M1) store the current received message, and one link layer buffer stores the recovered link layer frame message;
step 2.2, setting two check tables T0 and T1 to store the check result of the redundant channel; when receiving the message, carrying out CRC (cyclic redundancy check) on the APDU (advanced packet data Unit) data block in a pipeline mode, wherein the pass is 0, and the failure is 1; after calculation, storing the check result in T0 and T1 according to the serial number of the data block;
and 2.3, restoring fault data: after the receiving verification is completed, judging the verification result of each block in T0;
if the value is 0, removing additional information such as sequence number, length, verification and the like from the data block corresponding to the verification result in the M0, and storing the data block in a corresponding position in the M2;
if the check result is 1, judging the check result corresponding to the block in T1; if the data block is 0, the additional information of the corresponding data block in M1 is removed and the data block is stored in the corresponding position in M2; if the number is 1, setting a channel abnormal alarm;
if all the data in T0 or T1 are 1, setting a channel abnormal alarm;
and 2.4, after all the data blocks are subjected to error detection and recovery, recalculating the characteristic information such as the frame length and the like, framing and storing the data blocks into a link layer receiving buffer M2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010585954.9A CN111726288B (en) | 2020-06-24 | 2020-06-24 | Real-time data transmission and recovery method and system for power secondary equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010585954.9A CN111726288B (en) | 2020-06-24 | 2020-06-24 | Real-time data transmission and recovery method and system for power secondary equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111726288A CN111726288A (en) | 2020-09-29 |
| CN111726288B true CN111726288B (en) | 2022-07-19 |
Family
ID=72568601
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010585954.9A Active CN111726288B (en) | 2020-06-24 | 2020-06-24 | Real-time data transmission and recovery method and system for power secondary equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111726288B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113098663B (en) * | 2021-03-31 | 2022-10-14 | 国网浙江省电力有限公司电力科学研究院 | ASDU (asynchronous serial bus) frame transmission method, receiving method and system based on GSP (generalized likelihood protocol) |
| CN114554585B (en) * | 2022-02-28 | 2024-02-13 | 南京国电南自电网自动化有限公司 | Data synchronization method for differential protection of 5G communication line |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006021141A1 (en) * | 2004-08-24 | 2006-03-02 | Huawei Technologies Co. Ltd. | Method for restoring the missing data packets |
| CN105915737A (en) * | 2016-06-15 | 2016-08-31 | Tcl移动通信科技（宁波）有限公司 | Circuit switching method and system |
| CN106127822A (en) * | 2016-03-16 | 2016-11-16 | 上海海笑网络技术有限公司 | At physical isolation terminal room based on encoding of graphs one-way data transmission method and system |
| CN107623646A (en) * | 2017-09-06 | 2018-01-23 | 华为技术有限公司 | Data flow transmission method, send equipment and receiving device |
| CN111246428A (en) * | 2019-11-20 | 2020-06-05 | 广东纬德信息科技股份有限公司 | Network reliable communication method, system, device and storage medium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10033779B2 (en) * | 2009-07-08 | 2018-07-24 | Dejero Labs Inc. | Multipath data streaming over multiple wireless networks |
-
2020
- 2020-06-24 CN CN202010585954.9A patent/CN111726288B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006021141A1 (en) * | 2004-08-24 | 2006-03-02 | Huawei Technologies Co. Ltd. | Method for restoring the missing data packets |
| CN106127822A (en) * | 2016-03-16 | 2016-11-16 | 上海海笑网络技术有限公司 | At physical isolation terminal room based on encoding of graphs one-way data transmission method and system |
| CN105915737A (en) * | 2016-06-15 | 2016-08-31 | Tcl移动通信科技（宁波）有限公司 | Circuit switching method and system |
| CN107623646A (en) * | 2017-09-06 | 2018-01-23 | 华为技术有限公司 | Data flow transmission method, send equipment and receiving device |
| CN111246428A (en) * | 2019-11-20 | 2020-06-05 | 广东纬德信息科技股份有限公司 | Network reliable communication method, system, device and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111726288A (en) | 2020-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7047475B2 (en) | CRC encoding scheme for conveying status information | |
| JP3816529B2 (en) | Interconnect failure detection and location method and apparatus | |
| US20030206527A1 (en) | Transmitting data between multiple computer processors | |
| JP4308297B2 (en) | Communication device and switch processing device | |
| CN111726288B (en) | Real-time data transmission and recovery method and system for power secondary equipment | |
| US6601210B1 (en) | Data integrity verification in a switching network | |
| CN103957155A (en) | Message transmission method and device and interconnection interface | |
| US8209594B2 (en) | Sending device, receiving device, communication control device, communication system, and communication control method | |
| JP2015136104A (en) | Serial link fault detection system and method | |
| JP5256855B2 (en) | Data transfer device and data transfer method control method | |
| JP4079940B2 (en) | Data transmission method and method | |
| CN114884767B (en) | Synchronous dual-redundancy CAN bus communication system, method, equipment and medium | |
| JPWO2009147735A1 (en) | Information processing apparatus, data transmission apparatus, and data transfer method for data transmission apparatus | |
| JP2000349792A (en) | Data transmission device | |
| JP2016052074A (en) | Communication device | |
| CN104994017B (en) | A kind of network router for including packet-receiving module | |
| JP6295609B2 (en) | Reception device, communication system, and program | |
| US20160048422A1 (en) | Error detection device and error detection method | |
| US9274880B1 (en) | Methods and apparatus for detecting and correcting errors in high-speed serial communications systems | |
| CN112083710B (en) | Vehicle-mounted network CAN bus node monitoring system and method | |
| WO2016042731A1 (en) | Wireless control system, and method for monitoring wireless link error | |
| CN105207891B (en) | A kind of highly reliable bus message transmission method based on service life screening | |
| Sauter et al. | Majority Manchester decoding for active redundant data transmission | |
| Schwarz et al. | A Communication Observer for Monitoring the Safety Integrity Level in Real-time | |
| US20110320900A1 (en) | Apparatus and method for error check of transmission data |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |