CN103856375A - Single-slave end multi-master end distributed Ethernet system, construction method and communication method of single-slave end multi-master end distributed Ethernet system - Google Patents

Abstract

The invention discloses a single-slave-multi-master distributed Ethernet system, a construction method and a communication method that can be used in various complicated industrial occasions. Including a host computer connected to an Ethernet switch with a specified IP address and floating port number; the Ethernet switch is at least one of the above Ethernet switches, and each Ethernet switch has its fixed IP address and port number, connect the terminal device through a serial port/Ethernet converter. The present invention adopts a reverse structure with one slave and multiple masters. The biggest advantage is that it will not increase the communication burden of the system with the increase of the number of nodes under the premise of realizing the communication status of the master from the slave, which greatly guarantees The stability and safety of the system, the communication structure design of the slave end also adopts the asynchronous multi-thread method, so that the slave end can monitor the communication status of all the master ends at the same time, greatly improving the communication efficiency and stability of the system.

Description

Single-slave multi-master distributed Ethernet system and its construction method and communication method

technical field

The invention discloses a single-slave-multi-master distributed Ethernet system, a construction method and a communication method that can be used in various complicated industrial occasions.

Background technique

Ethernet communication mostly adopts a single-master-multiple-slave communication structure framework, which is suitable for a limited and fixed number of communication slaves. With the complexity of the communication structure, the number of communication slaves continues to increase, and the number of slaves cannot be fixed under many working conditions. In this case, the burden on the communication master continues to increase and the total amount cannot be estimated. The communication system is in a state of increasing burden and risk, which brings great hidden dangers to the stability of the system.

Contents of the invention

In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a single-slave multi-master distributed Ethernet communication method and device that can be used in various complex industrial occasions.

The technical solution adopted by the present invention to achieve the above object is: a single-slave multi-master distributed Ethernet system, including

A host computer, connected to an Ethernet switch, has a specified IP address and a floating port number;

The Ethernet switch is at least one of the above Ethernet switches, each Ethernet switch has its fixed IP address and port number, and is connected to the terminal equipment through a serial port/Ethernet converter.

Each serial/Ethernet converter is assigned a unique IP address within the 192.168.1 segment.

A method for constructing a single-slave multi-master distributed Ethernet system, using a host computer as a slave, and a plurality of Ethernet switches connected to the host computer as hosts, comprising the following steps:

Fix the IP address and port number of each master end, specify the IP address of the slave end instead of fixing the port number;

The number of all masters scanned starts with a number, and gradually increases the port number by adding 1, so that each master corresponds to a port number;

The slave end binds the master end through a fixed IP address and a floating port number, and sends communication requests with different master ends; the master end records the slave end IP address and port number that sent the communication request, and uses the IP address and port number Communicate with the slave.

The slave end opens up the same number of port numbers according to the number of the master end.

The one number is 10000.

A communication method for a single-slave multi-master distributed Ethernet system, using a host computer as a slave, and a plurality of Ethernet switches connected to the host computer as a host, comprising the following steps:

Start an independent "reading thread" on the slave side by constructing a thread constructor of ThreadStart type;

After the memory area storing the read data is full of data, a trigger signal is generated to trigger the "read thread" to realize an asynchronous "read thread".

The master end implements "delegation" to process data asynchronously through the method of dynamically assigning parameters; upload the data to the slave end.

Described data is stored in the database, and its storage method is: add database ADOX dynamic link; Add database ADODB dynamic link; Specify data table storage position; Specify data table key value number; Name each key value; Periodically insert data ;Update the database and return to the step of periodically inserting data

The method and device of the present invention completely subvert this traditional communication framework, adopting a reverse structure with one slave and multiple masters. The increase of the purpose increases the communication burden of the system, which greatly guarantees the stability and security of the system. The communication structure design of the slave end also adopts an asynchronous multi-threading method, so that the slave end can monitor the communication status of all the master ends at the same time, greatly improving System communication efficiency and stability. It has the following advantages:

1. All terminal devices are added to Ethernet for data transmission, and the unified protocol is conducive to expansion;

2. The number of terminal devices connected to the system can be expanded by a multiple of 24 (the total data volume is less than 1GB/s), which truly realizes the higher requirements of the distributed industrial field;

3. Adopting a unique special network architecture with the upper computer as the slave station and the lower computer as the master station, which greatly reduces the resource requirements of the upper computer and makes "scalable" truly possible;

4. Data monitoring, reading, and processing adopt independent threads and entrusted methods, which minimizes the burden on the host computer and greatly improves the stability and processing capacity of the system;

5. Use the database to provide complete real-time data for the application, bringing convenience for subsequent data analysis and processing.

Description of drawings

Fig. 1 schematic diagram of device circuit of the present invention;

Fig. 2 control program flow chart of the single-slave multi-master communication construction method of the present invention;

Fig. 3 is a flow chart of the control program of the database storage method of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1-3, the system includes a host computer that runs the control program that realizes the single-slave multi-master distributed Ethernet communication method; the host computer is connected to a 10M/100M network switch through an 8-core network cable; the switch is connected to the network through a network cable Connect RS232/Ethernet converter, RS485/Ethernet converter, RS422/Ethernet converter, Ethernet video server, Ethernet audio server. Assign each converter a unique IP address within the 192.168.1 segment; each converter can be directly connected to terminal equipment, including S232 equipment, RS485 equipment, RS422 equipment, video equipment, audio equipment; the switch is connected to video decoding through a network cable device and audio decoding device.

The communication method of single-slave and multi-master first fixes the IP address and port number of each master, but only specifies the IP of the slave instead of the fixed port number, and then scans the number of all masters connected to the network, numbering from 10000 and adding The method of 1 gradually increments the port number to correspond to each master. Establish communication with each master end by binding a floating port number with a fixed IP address, and the master end records the slave end IP and port number requesting communication, and communicates with the slave end using this IP and port number.

The read data is read by asynchronous method, which saves system resources and reduces the burden of the main program. Each network device is processed by a separate thread pool. After the data cache is blocked, the data is processed in a delegated manner. The database is triggered by a timer trigger and stores data at fixed intervals. Both video and audio data are directly stored in a readable manner, which brings maximum convenience for playing video and audio.

A single-slave multi-master distributed Ethernet communication method with database function of the present invention includes a single-slave multi-master communication construction method and a database storage method, respectively as follows:

Single-slave multi-master communication construction method:

Detect the status of the switch, if it is abnormal, it will send an alarm and loop detection, if it is normal, it will continue to execute;

Detect the status of Ethernet servers No. 1~24, and send an alarm if there is a problem;

Fixed slave IP address;

Scan the number of masters entering the network;

Fixed master IP address and port number;

Open up the same number of port numbers on the slave side according to the number of the master side, and add 1 to ensure that the port numbers do not overlap;

Send communication requests to different masters through IP addresses and different port numbers;

The master end records the IP address and port number of the slave end and uses the IP address and port number to return data;

Open the function of data removal from the terminal;

Open an independent "read thread";

Asynchronous "read thread", loop hangs;

"Delegate" to process data asynchronously;

Upload the data to the host computer.

Database storage method:

Add database ADOX dynamic link;

Add database ADODB dynamic link;

Specify the storage location of the data table;

Specify the number of key values in the data table;

Name each key value;

Insert data periodically;

Update the database and go back to the periodic data entry and exit steps.

Claims (7)

1. A single-slave multi-master distributed Ethernet system, characterized in that, comprising A host computer, connected to an Ethernet switch, has a specified IP address and a floating port number; The Ethernet switch is at least one of the above Ethernet switches, each Ethernet switch has its fixed IP address and port number, and is connected to the terminal equipment through a serial port/Ethernet converter. 2. The single-slave multi-master distributed Ethernet system according to claim 1, wherein each serial port/Ethernet converter all specifies a unique IP address in the 192.168.1 segment. 3. a method for building a single-slave multi-master distributed Ethernet system according to claim 1, wherein a host computer is a slave terminal, and a plurality of Ethernet switches connected to the host computer As the client, including the following steps: Fix the IP address and port number of each master end, specify the IP address of the slave end instead of fixing the port number; The number of all masters scanned starts with a number, and gradually increases the port number by adding 1, so that each master corresponds to a port number; The slave end binds the master end through a fixed IP address and a floating port number, and sends communication requests with different master ends; the master end records the slave end IP address and port number that sent the communication request, and uses the IP address and port number Communicate with the slave. 4. The method for constructing a single-slave multi-master distributed Ethernet system according to claim 3, wherein said slaves open up the same number of port numbers according to the number of masters. 5. The method for constructing a single-slave multi-master distributed Ethernet system according to claim 3, wherein said one number is 10000. 6. A communication method of a single-slave multi-master distributed Ethernet system according to claim 1, wherein a host computer is used as a slave terminal, and a plurality of Ethernet switches connected to the host computer As the client, including the following steps: Start an independent "reading thread" on the slave side by constructing a thread constructor of ThreadStart type; After the memory area storing the read data is full of data, a trigger signal is generated to trigger the "read thread" to realize an asynchronous "read thread". The master end implements "delegation" to process data asynchronously through the method of dynamically assigning parameters; upload the data to the slave end. 7. the communication method of single slave end multi-master end distributed Ethernet system according to claim 6, is characterized in that, described data is stored in the database, and its storage method is: add database ADOX dynamic link; Add database ADODB Dynamic link; specify the storage location of the data table; specify the number of key values in the data table; name each key value; periodically insert data; update the database and return to the step of periodically inserting data.

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