CN109360408B - Data communication method based on plastic optical fiber - Google Patents

Abstract

The invention is a data communication method based on plastic optical fiber, the plastic optical fiber network adopts the hardware architecture of the software relay communication scheme, the data receiving and transmitting pins of two adjacent two optical transceivers are directly connected with a processor, and the function that a single optical transceiver can receive and transmit data is reserved; under the control of the processor, after one optical transceiver of two adjacent optical transceivers receives one byte data or one bit data, the buffer memory is carried out inside the processor, and the other optical transceiver immediately sends the data. In the invention, after one optical transceiver in two adjacent optical transceivers receives one byte data or one bit data, the buffer memory is carried out in the processor, and simultaneously, the transmission from the other optical transceiver is carried out immediately, so that the delay can be greatly reduced.

Description

Data communication method based on plastic optical fiber

Technical Field

The invention relates to the field of local data transmission of power consumption information acquisition systems, in particular to a data communication method based on plastic optical fibers.

Background

In order to improve the level of rapidness of market response, improve the quality of customer service and meet the requirement of 'lean management', a marketing mechanism which is adaptive to market change and rapidly reflects the requirements of customers is gradually established, and the real-time acquisition and monitoring of electricity utilization information of electric power users must be realized, so that marketing management and various business requirements are practically serviced. The electricity consumption information acquisition system realizes the on-line monitoring of the metering device and the real-time acquisition of important information such as user load, electric quantity, voltage and the like, and timely, completely and accurately provides basic data for the information system, thereby providing support for analysis and decision making of each link of enterprise operation management, improving the intensive, lean and standardized management level of the enterprise, and at present, the real-time acquisition and monitoring of the electricity consumption information of the set of electric power users is called as a meter reading system (electric energy meter acquisition).

The plastic optical fiber communication technology mainly solves one of the last 1 km system solutions in the real-time acquisition and monitoring system of the power utilization information of the power users, establishes a communication channel from a concentrator device to a meter device in the low-voltage centralized meter reading system, and realizes meter data reading, remote issuing of rate data and remote opening and closing control. Compared with the system solutions of the original low-voltage power line narrowband carrier communication technology and the micropower wireless communication technology, the plastic optical fiber technology has the characteristics of being high in speed, high in reliability and the like and is provided with independent communication media and links.

The existing plastic optical fiber communication schemes mainly have two types, and the different points are mainly different in a relay cascading mode. The relay communication mode for hardware connection is generally adopted by the plastic optical fiber communication module, and the data receiving and transmitting pins of the two optical receiving and transmitting devices are connected together in a hardware mode. And the other is a software relay communication mode, the receiving and transmitting pins of the two optical transceiver devices of the plastic optical fiber communication module are connected with the module processor, the data relay forwarding is processed through the processor software, and after the module processor receives a data frame of one optical transceiver, the module processor firstly analyzes and filters the data, and then forwards the data from the other optical transceiver device according to the requirement.

At present, the plastic optical fiber mainly uses 460nm blue light and 520nm red light for communication, and the transmission loss of the plastic optical fiber to the red light and the blue light is 100 dB/Km-160 dB/Km. Plastic optical fibers are not suitable for long distance communication due to the relatively large attenuation. In the low-voltage user electricity consumption centralized meter reading system, a communication node relay cascade mode is adopted, so that the communication distance is extended, and the purpose of using in the centralized meter reading system is achieved. The relay cascade mode is adopted, so that the cost of communication transmission speed is sacrificed, data is forwarded once through a relay, and the speed is reduced by 1 time from the whole view. In this way, the number of relay cascade stages in an actual system is limited, and the relay cascade cannot be infinitely cascade, and the communication scheme of the current common system is that the proposed relay stage cannot exceed 64 stages. Based on the limitation of the relay level, gateway type equipment is added in the practical application scene, a level 1 network is built by using the network type equipment, and then a level 2 network is built by extending the network type equipment. The network structure is relatively complex, and meanwhile, the difficulty is increased for later operation and maintenance.

At present, a common plastic optical fiber communication scheme generally adopts hardware connection or a processor to carry out software relay communication, wherein the relay communication scheme adopts the hardware connection, namely a single optical transceiver is in a simplex working mode, two optical transceivers realize half-duplex receiving and transmitting, the whole link is required to be connected into a loop state, the network structure is fixed, network branching cannot be flexibly carried out, and the whole loop node cannot be influenced to communicate after one node fault occurs in the network. The software relay communication scheme is carried out by adopting the processor, the single optical transceiver can realize half-duplex operation, so that the network structure can be flexibly arranged, but the data relay is carried out by carrying out software processing and forwarding by taking a data frame as a unit, the speed of the relay 1 stage is reduced by 1 time, the network relay level is strictly limited based on the minimum requirement of the application communication rate, and the network can only be used for separating the network to reduce the relay level after exceeding the limit relay level.

Disclosure of Invention

The invention aims to solve the problems that a plastic optical fiber data transmission network is prolonged in data transmission in a low-voltage user electricity consumption information acquisition system, the network construction is slow, the network fault diagnosis is difficult and the like. A data communication method based on plastic optical fiber is provided, which is a software relay communication method by a processor, and the data relay is realized by processing and forwarding the data by taking data bytes or data bits as units, so that the delay can be greatly reduced.

The technical scheme of the invention is as follows: the data communication method based on the plastic optical fiber adopts a hardware architecture of a software relay communication scheme, and the data receiving and transmitting pins of two adjacent two optical transceivers are directly connected with a processor, so that the function that a single optical transceiver can receive and transmit data is reserved; under the control of the processor, after one optical transceiver of two adjacent optical transceivers receives one byte data or one bit data, the buffer memory is carried out inside the processor, and the other optical transceiver immediately sends the data.

In the invention, after one optical transceiver in two adjacent optical transceivers receives one byte data or one bit data, the buffer memory is carried out in the processor, and simultaneously, the transmission from the other optical transceiver is carried out immediately, so that the delay can be greatly reduced.

Further, in the above data communication method based on plastic optical fiber: the plastic optical fiber network constructs a single-wire type or ring type or hybrid type structure.

Further, in the above data communication method based on plastic optical fiber: the fast network learning method based on byte stream or bit stream data relay transmission mechanism comprises the following steps:

firstly, a master node initiates a network learning starting command, the command is sent to all nodes in a network in a broadcasting mode, and after the node receives the network learning command, a learning mode is carried out;

then, the master node starts to initiate the counting process, starts from the master node, starts counting from 0, adds 1 to report downwards after the latter node receives 0, until the terminal node, if the terminal node is a ring network, returns to the master node;

finally, the master node collects node information step by step through the sequence numbers, and finally the purpose of learning the topology structure distributed by the whole network node and relay information to the master node is achieved.

Further, in the above data communication method based on plastic optical fiber: in the running process of the plastic optical fiber network, the method for accurately positioning the network fault is realized on the basis of a rapid network learning method;

the master node starts network learning irregularly, and compares the newly learned network topology structure with the historically learned topology structure, so that the network can be accurately judged that the communication interruption fault occurs at the node of the line.

In the invention, the data relay forwarding mechanism based on byte stream or bit stream ensures the bottom time delay of relaying and forwarding network data, greatly expands the relay level of network nodes, supports the application of a simple single-loop plastic optical fiber network structure on site, simplifies the network structure, improves the running reliability of the network and reduces the construction cost of plastic optical fiber network construction; the self-healing capacity of network faults is improved by a rapid network learning algorithm; and the network fault positioning function improves the maintenance efficiency of the network in the later period and saves the manual investigation labor cost.

The invention will now be described in detail with reference to the drawings and to specific embodiments.

Drawings

Fig. 1 is a schematic diagram of a connection structure of two adjacent nodes in the plastic optical fiber network according to embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of data communication according to embodiment 1 of the present invention.

Fig. 3 is a schematic diagram of a single-wire structure of a plastic optical fiber network according to embodiment 1 of the present invention.

Fig. 4 is a schematic view of a ring structure of a plastic optical fiber network according to embodiment 1 of the present invention.

Fig. 5 is a schematic diagram of accurately judging that a network has a communication interruption fault at a node of the line according to embodiment 1 of the present invention.

Detailed Description

In embodiment 1, the hardware architecture of the software relay communication scheme is also adopted in this embodiment, and the data receiving and transmitting pins of the optical transceiver 1 and the optical transceiver 2 are directly connected to the processor, as shown in fig. 1, so that the function that a single optical transceiver can perform data receiving and transmitting is reserved.

The local data transmission of the current electrical information acquisition system is different from the local data transmission of the current electrical information acquisition system, and is a data forwarding mechanism adopting byte stream transmission, or a data forwarding mechanism adopting bit streams, as shown in fig. 2, a node N4 transmits data to a main node N0, and the node N1, the node N2 and the node N3 are required to perform data relay forwarding in the middle. As a relay node, the node N1, the node N2, and the node N3 do not forward data after receiving a complete data frame, but transmit data from one optical transceiver immediately while buffering inside the processor after receiving 1 byte of data. The delay time from the node N4 to the node N3 is 1 byte time, the delay time from the node N4 to the node N2 is 2 byte time, the delay time of only 1 byte is increased in the middle of adding 1-level relay, and finally the delay time from the node N4 to the master node N0 is 4 byte transmission time. The transmission rate of the current optical transceiver is calculated as 1Mbps, a 100-level relay plastic optical fiber network is constructed, 10 bits of data transmission is carried out by using UART transmission protocol, namely, 1 byte of 8 bits of data plus a start bit and a stop bit, and the data transmission delay from a source node to a terminal node in the data is only 1.0ms.

Based on the low-delay data forwarding mechanism and the half-duplex operation capability of the single optical transceiver of the present embodiment, in practical application, the plastic optical fiber network may be constructed in a single-line type and ring type structure as shown in fig. 3 and 4, and may even be a hybrid network of fig. 3 and 4. As the master node N0, network learning is required, and the topology structure of the entire network and the relay relationship of each node are learned to the master node, so as to prepare for network data transmission and later operation and maintenance.

The present embodiment employs a fast network learning algorithm based on a byte stream data relay transport mechanism. The master node N0 first initiates a network learning starting command, and sends the command to all nodes in the network in a broadcasting mode, and the nodes perform a learning mode after receiving the network learning command. After all nodes enter a learning mode, the master node starts to initiate a counting flow, starts to count from the master node N0, starts counting from 0, adds 1 to report downwards after the node N1 receives 0, and returns to the master node N0 if the node is a peripheral node. After a round of counting, all nodes know that the relay level of the network where the node is located is an allocation sequence number. And then the master node N0 collects node information step by step through sequence numbers, and finally the purpose of learning the topology structure distributed by the whole network node and relay information to the master node is achieved.

The embodiment of the invention realizes the method for accurately positioning the network fault on the basis of a rapid network learning algorithm. During the operation of the plastic optical fiber network, conditions such as node damage or faults, optical fiber line damage interruption and the like can occur. The master node N0 may initiate network learning at an irregular period, and compare the newly learned network topology structure with the historically learned topology structure, so as to accurately determine that the network has a communication interruption fault at that node of that line. As shown in fig. 5, the history network topology is a ring network of N1 to N6, and becomes two linear networks from the master node N1 to the node N3 and from the node N6 to the node N4 after relearning, it can be determined that the nodes N3 and N4 directly fail.

Claims (2)

1. The data communication method based on plastic optical fiber adopts a hardware architecture of a software relay communication scheme, and the data receiving and transmitting pins of two adjacent optical transceivers are directly connected with a processor, so that the function of transmitting and receiving data of a single optical transceiver is reserved; the method is characterized in that:

under the control of the processor, after one optical transceiver of two adjacent optical transceivers receives one byte data or one bit data, the buffer memory is carried out in the processor, and meanwhile, the buffer memory immediately sends the byte data or the one bit data from the other optical transceiver;

the fast network learning method based on byte stream or bit stream data relay transmission mechanism comprises the following steps:

firstly, a master node initiates a network learning starting command, the command is sent to all nodes in a network in a broadcasting mode, and after the node receives the network learning command, a learning mode is carried out;

then, the master node starts to initiate the counting process, starts from the master node, starts counting from 0, adds 1 to report downwards after the latter node receives 0, until the terminal node, if the terminal node is a ring network, returns to the master node;

finally, the master node collects node information step by step through serial numbers, and finally, the purpose of learning the topology structure and relay information distributed by the whole network node to the master node is achieved;

in the running process of the plastic optical fiber network, the method for accurately positioning the network fault is realized on the basis of a rapid network learning method;

the master node starts network learning irregularly, and compares the newly learned network topology structure with the historically learned topology structure, so that the network can be accurately judged that the communication interruption fault occurs at the node of the line.

2. The plastic optical fiber-based data communication method according to claim 1, wherein: the plastic optical fiber network constructs a single-wire type or ring type or hybrid type structure.

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