Ethereum layering

1. If you buy, you can go directly to the exchange. But if you ask about the investment method, it will be difficult to learn for a while. It is suggested to take a look at the recent market of bitcoin, and password finance can see the recent market and analysis.

2.

Russian monetary unit: ruble

ruble российский рубль ， (Russian) Russian rule (or rouble), symbol: &# 8381 The original symbol RBS. RBL). Currency code: rub. Regions of use: Russia and self declared independence of Abkhazia and South Ossetia. Inflation rate: 7%, russian rubles Рублевка It is the standard unit of currency in Russia. The token is goby Копейка 1 rouble = 100 Gobi. There are rubles 10, 50, 100, 500, 1000, 5000 in denomination, rubles 10, 5, 2, 1 and Gobi 50, 10, 5, 1 in denomination

3. How to choose the framework? Considering privacy and taxation, we must choose those island countries that are ty-free paradise. So is foreign trade, such as BVI and Cayman. How good is the privacy? Even if I tell you the full name of the company, it's not a very high-level segment. I can't understand the company's information at all. To put it bluntly, after the company is registered, you don't know how to verify it. The privacy can be so good
then, the Singapore foundation will apply for registration as a member of the island company. The ultimate goal of the framework is to achieve a clean and complete international legal cutting. Finally, the Singapore foundation will organize and authorize the domestic promotion team and technology R & D team to carry out project promotion and R & D, or authorize other detailed operations
the codewords are very tired, so I can only tell the general direction. If there is anything unclear, you can ask!

6. About the two methods you mentioned, I still have the following questions
for the first method, I know that cp1w-cif41 can not be used on cp1e series PLC. How many TCP connections between PLC and PLC can cp1w-cif41 support at most? Cp1w-cif41 is an option, where is it installed in PLC? Take CP1H PLC as an example, it can have a RS232C option board slot and a RS422A / 485 option board slot, no Ethernet adapter slot, or convert the original serial port RS232 to Ethernet interface? It would be better to have cp1w-cif41 in Chinese
for the second method, why add a CJ unit adapter cp1w-ext01? Is it because CJ Ethernet unit cj1w-etn21 must be connected to CJ unit adapter cp1w-ext01 when CP1H is connected?

7. After reading the landlord's understanding of OSI layered model, you didn't understand this step, because the landlord didn't even understand the basic concept and function of each layer of OSI seven layer model
let me first introce the basic concept of the seven layer model and the functions of each layer:
this problem is a bit abstract and difficult to understand for beginners
for computer or computer network, it includes many kinds of hardware devices, such as computer itself, network card, switch, router, etc. But the hardware itself can't work, just like a newly bought computer without an operating system (such as Windows XP), it can't do anything except waste electricity. So what can make these hardware devices work is the software system installed on the devices and the "Protocol". And these software protocols are many and complex, in order to make these complex protocols easier to operate, understand and learn. These protocols are divided into seven categories and seven layers according to different functions, and each layer works according to its own specific functions. To realize the transmission of data

first of all, we need to understand the functions of each layer of OSI seven layer model

the seventh layer: application layer data user interface, providing user program "interface"
layer 6: the presentation of data in the presentation layer and the implementation of specific functions, such as data encryption
layer 5: session layer data allows users on different machines to establish session relationship, such as windows
layer 4: transport layer segment realizes data communication between user processes on different hosts, reliable and unreliable transmission, error detection of transport layer, flow control, etc
Layer 3: network layer packet provides logical address (IP) and routing, data from the source to the destination
transmission
Layer 2: data link layer frame encapsulates the upper layer data into a frame, uses MAC address to access the media, error detection and correction

Layer 1: bit stream transmission between bit stream devices in physical layer, physical interface, electrical characteristics, etc<

the following is a detailed explanation of the functions of each layer of OSI seven layer model:

OSI seven layer Model OSI seven layer model is called open system interconnection reference model. OSI seven layer model is a kind of framework design method
OSI seven layer model realizes reliable communication between different networks of different systems through seven hierarchical structure models, Therefore, its most important function is to help different types of hosts achieve data transmission
physical layer: the lowest or first layer of OSI model, which includes physical networking media, such as cable connectors. The physical layer protocol generates and detects voltage to send and receive signals carrying data. Insert a network interface card into your PC, and you've built the foundation of computer networking. In other words, you provide a physical layer. Although the physical layer does not provide error correction service, it can set the data transmission rate and monitor the data error rate. Network physical problems, such as wire disconnection, will affect the physical layer
data link layer: the second layer of OSI model, which controls the communication between network layer and physical layer. Its main function is how to transfer data reliably on unreliable physical circuit. In order to ensure the transmission, the data received from the network layer is divided into specific frames that can be transmitted by the physical layer. Frame is a structure packet used to move data. It includes not only the original data, but also the network addresses of sender and receiver, as well as error correction and control information. The address determines where the frame will be sent, and the error correction and control information ensures that the frame will arrive error free
the function of the data link layer is independent of the network and its nodes and the type of physical layer used, and it does not care whether wo rd, e Xcel or I NTE r NTE are running. Some connecting devices, such as switches, work in the data link layer because they need to decode the frame and use the frame information to send the data to the correct receiver
network layer: the third layer of OSI model, whose main function is to translate the network address into the corresponding physical address and decide how to route the data from the sender to the receiver
the network layer determines the best path from node a in one network to node B in another network by comprehensively considering the transmission priority, network congestion, quality of service and the cost of optional routing. Because the network layer deals with routing, and the router connects all segments of the network and intelligently guides data transmission, it belongs to the network layer. In the network, "routing" is based on addressing scheme, usage mode and accessibility to guide data transmission
transport layer: the most important layer in OSI model. The transmission protocol controls the flow at the same time or sets the appropriate transmission rate based on the speed of the data that the receiver can receive. In addition, the transport layer compulsorily divides the longer packets according to the maximum size that the network can handle. For example, Ethernet cannot receive packets larger than 1500 bytes. The transport layer of the sender node divides the data into smaller pieces, and arranges a sequence number for each piece, so that when the data reaches the transport layer of the receiver node, it can be reorganized in the correct order. This process is called sorting
one of the transport layer services is TCP (transmission control protocol) in TCP / IP protocol suite, and the other is SPX (sequential packet switching) in IPX / SPX protocol suite
session layer: responsible for establishing and maintaining communication between two nodes in the network. The functions of session layer include: establishing communication link, keeping communication link unblocked, synchronizing the dialogue between two nodes, deciding whether communication is interrupted and deciding where to resend when communication is interrupted
you may often hear people call the conversation layer the "traffic police" of network communication. When you dial to your ISP (Internet service provider) to connect to the Internet, the session layer on the ISP server negotiates the connection between you and the session layer on your PC client. If your phone line accidentally falls off the wall jack, the session layer on your terminal will detect the connection interruption and initiate the connection again. The session layer sets the communication deadline by determining the priority and time of the node communication
presentation layer: the translator between the application and the network. In the presentation layer, the data will be formatted according to the scheme that the network can understand; This format also varies depending on the type of network used
represents the decryption and encryption of management data, such as the processing of system password. For example, when you query your bank account on the Internet, you use a secure connection. Your account data is encrypted before it is sent. At the other end of the network, the presentation layer will decrypt the received data. In addition, the presentation layer protocol decodes and encodes the image and file format information
application layer: it is responsible for providing interface for software so that the program can use network services. The term "application layer" does not refer to a special application running on the network. The services provided by the application layer include file transfer, file management and e-mail information processing.

8. OSI seven layer model is called open system interconnection reference model. OSI seven layer model is a kind of framework design method, Therefore, its most important function is to help different types of hosts achieve data transmission
physical layer: the lowest or first layer of OSI model, which includes physical networking media, such as cable connectors. The physical layer protocol generates and detects voltage to send and receive signals carrying data. Insert a network interface card into your PC, and you've built the foundation of computer networking. In other words, you provide a physical layer. Although the physical layer does not provide error correction service, it can set the data transmission rate and monitor the data error rate. Network physical problems, such as wire disconnection, will affect the physical layer
data link layer: the second layer of OSI model, which controls the communication between network layer and physical layer. Its main function is how to transfer data reliably on unreliable physical circuit. In order to ensure the transmission, the data received from the network layer is divided into specific frames that can be transmitted by the physical layer. Frame is a structure packet used to move data. It includes not only the original data, but also the network addresses of sender and receiver, as well as error correction and control information. The address determines where the frame will be sent, and the error correction and control information ensures that the frame will arrive error free
the function of the data link layer is independent of the network and its nodes and the type of physical layer used, and it does not care whether wo rd, e Xcel or I NTE r NTE are running. Some connecting devices, such as switches, work in the data link layer because they need to decode the frame and use the frame information to send the data to the correct receiver
network layer: the third layer of OSI model, whose main function is to translate the network address into the corresponding physical address and decide how to route the data from the sender to the receiver
the network layer determines the best path from node a in one network to node B in another network by comprehensively considering the transmission priority, network congestion, quality of service and the cost of optional routing. Because the network layer deals with routing, and the router connects all segments of the network and intelligently guides data transmission, it belongs to the network layer. In the network, "routing" is based on addressing scheme, usage mode and accessibility to guide data transmission
transport layer: the most important layer in OSI model. The transmission protocol controls the flow at the same time or sets the appropriate transmission rate based on the speed of the data that the receiver can receive. In addition, the transport layer compulsorily divides the longer packets according to the maximum size that the network can handle. For example, Ethernet cannot receive packets larger than 1500 bytes. The transport layer of the sender node divides the data into smaller pieces, and arranges a sequence number for each piece, so that when the data reaches the transport layer of the receiver node, it can be reorganized in the correct order. This process is called sorting
one of the transport layer services is TCP (transmission control protocol) in TCP / IP protocol suite, and the other is SPX (sequential packet switching) in IPX / SPX protocol suite
session layer: responsible for establishing and maintaining communication between two nodes in the network. The functions of session layer include: establishing communication link, keeping communication link unblocked, synchronizing the dialogue between two nodes, deciding whether communication is interrupted and deciding where to resend when communication is interrupted
you may often hear people call the conversation layer the "traffic police" of network communication. When you dial to your ISP (Internet service provider) to connect to the Internet, the session layer on the ISP server negotiates the connection between you and the session layer on your PC client. If your phone line accidentally falls off the wall jack, the session layer on your terminal will detect the connection interruption and initiate the connection again. The session layer sets the communication deadline by determining the priority and time of the node communication
presentation layer: the translator between the application and the network. In the presentation layer, the data will be formatted according to the scheme that the network can understand; This format also varies depending on the type of network used
represents the decryption and encryption of management data, such as the processing of system password. For example, when you query your bank account on the Internet, you use a secure connection. Your account data is encrypted before it is sent. At the other end of the network, the presentation layer will decrypt the received data. In addition, the presentation layer protocol decodes and encodes the image and file format information
application layer: it is responsible for providing interface for software so that the program can use network services. The term "application layer" does not refer to a special application running on the network. The services provided by the application layer include file transfer, file management and e-mail information processing.