I. SuperIO communication mechanism. SuperIO Communication Mechanism

I. SuperIO communication mechanism. SuperIO Communication Mechanism
1.1 application scenarios

Communication Platform interaction objects include two aspects: first, interaction with hardware products. 2. Interaction with software products. Generally, communication platforms are used in two scenarios:

1) The communication platform is applied to PCs.

It is mainly used in automatic station industrial computer to collect data of hardware devices through RS485/RS232, RJ45, 4-20mA, and other methods. At the same time, the communication platform interacts with the software on the server to upload data information and receive control commands.

2) communication platform applications on the server

The terminal device connects to the communication platform with a 3G/4G network, a wired private network, and a satellite for data interaction. The terminal devices include PCs, mobile terminals (mobile phones), and monitoring devices.

 

1.2 communication mechanism Overview

For the communication platform, the communication part is always the core of the software and requires high real-time performance and high stability. The software architecture determines the stability of software operation and the scalability in the future. Therefore, a good design of communication mechanisms and control methods is required.

Generally, the communication mechanism is called the call response mode or the master/slave mode. The host sends a request command to verify data integrity after receiving the command from the host, and determines whether to send the command to itself. After the verification is successful, the host returns the specified data information to complete the communication.

Call response communication mechanisms include:

1.3 integration of serial ports and networks

When developing device drivers or Protocol drivers, the same driver module must support both RS485/RS232 and RJ45 communication methods, avoid repeated development due to different protocols or different communication methods. Minimize the workload when the business logic is unified. Therefore, in terms of communication methods, unified interfaces should be logically implemented to ensure the universality of the entire communication platform.

The interface design is as follows:

 

1.4 Serial Communication Mechanism

Due to the limitations of serial communication, data confusion occurs when multiple hardware devices connect to the serial bus. The round-robin mode is used for call response communication.

(1) Polling Mode

When multiple devices are connected to the communication platform, the communication platform polls the scheduling device for communication tasks. At a certain time, only one device can send request commands and wait for receiving and returning data. After the device completes sending and receiving, the next device will perform communication tasks and round-robin the device in turn. For example:

1.5 Network Communication Mechanism

The Round-Robin communication mechanism ensures the orderly transmission and receipt of data to avoid confusion of Concurrent Data on the bus. However, this communication mechanism is suitable for serial communication at the cost of reducing performance, obviously, the advantages of network communication cannot be fully utilized in Ethernet communication.

Ethernet is an independent channel that supports full-duplex communication. To give full play to the advantages of Ethernet, the concurrent communication mode and automatic communication mode are added based on the polling communication mechanism. First, to improve the communication performance, and second, to achieve secondary development with more autonomous control.

(1) Polling Mode

The Ethernet round robin communication mode is consistent with the serial communication mode, for example:

(2) concurrency Mode

The concurrent communication mode is to send request commands from all devices in a centralized manner. After the hardware device receives the command, it verifies it. After the verification succeeds, it returns the data of the corresponding command. After the communication platform monitors the data information, receive the data before distributing and processing the data. For example:

(3) Automatic Control Mode

The self-controlled communication mode is similar to the concurrent communication mode. The difference is that the sending command operation is handed over to the device itself, or to the secondary developer. The secondary developer can independently send the command through event-driven. The hardware device verifies the received commands. After the verification succeeds, it returns the data of the corresponding commands. After the communication platform monitors the data information, it receives the data and then distributes and processes the data.

The self-controlled communication mode can provide secondary developers with a precise Real-time Data mechanism for scheduled requests, making the communication mechanism more flexible. You can also use the automatic communication mode to passively receive data without sending any data. For example:

 

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