Open fieldbus CC-Link features - Solutions - Huaqiang Electronic Network

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CC-Link is short for Control & Communication Link. It has outstanding advantages such as excellent performance, wide application and simple cost saving.
In general, we divide the network system into three to four levels: management layer, controller layer, component layer, and component layer, which means the device layer and the sensor layer. Due to the large data capacity of CC-Link and the choice of communication speed, CC-Link is a composite, open and adaptable network system that can adapt to higher management network to lower sensor layer network. Different ranges.
Due to its large data capacity, communication speed is wide.
First, the excellent performance of CC-Link:
CC-Link is a highly reliable, high performance network.
The advantages of CC-Link are as follows:
1) High-speed and large-capacity data transfer can set one of five communication speeds selectable from 156Kbps to 10Mbps.
The total length is determined by the maximum communication speed.
Each loop transfers data to 24 bytes and 150 bytes for communication transfer.
8 bytes (64 bits) for bit data transfer, 16 bytes (4 points RWr, 4 points RWw) for word transfer,
(L=>M 34 bytes).
The maximum size of each link scan is 2048 bits and 512 words.
In the case of 64 remote I/O stations, the link scan time is 3.7 milliseconds.
Stable and fast communication speed is the biggest advantage of CC-Link.
CC-Link has excellent performance for a wide range of systems.
When a communication speed of 10 Mbps is applied, the maximum communication distance is 100 meters; when the communication speed is 156 Kbps, the maximum communication distance is 1200 meters.
If you apply a repeater, you can also extend the total length of the network. The length of the communication cable can be extended to 13.2KM.
2) Topological structure Multi-point access, T-branch, star-shaped structure Three types of cables and connectors can support the connection of CC-Link components to any machine and system.
3) CC-Link makes distribution control a reality CC-Link is also used for low-cost intermediate control layer networks.
All local stations and smart stations can access cyclic data such as RX, RY, RWr, RWw arriving at the slave or from the slave. (But these data cannot be changed.) If these cyclic data are used, high-speed response and stable refresh time can be guaranteed, making intermediate control communication and central control system a reality.
Some applications require two networks, a control layer and a component layer. Such a system can only use CC-Link.
Since each station of CC-Link has a fixed range of cyclic data, it may limit the cyclic data, but it is a low-cost network after all.
4) Auto refresh function, reserved station function plc
Taking PLC as the main station of CC-Link as an example, the main station module manages the operation and data refresh of the entire network. The data refresh of the CPU of the main station module and the PLC can set the refresh parameters in the parameters of the main station, so that all the The network communication data and the network system monitoring data are automatically refreshed to the CPU of the PLC, and there is no need to write a refresh program. Therefore, it is not necessary to consider the structure of the buffer register area of ​​the CC-Link main station module and the correspondence between the data type and the buffer, simplifying Programming instructions, reduce program running steps, shorten scan cycle, and ensure real-time operation of the system.
The reservation station function shows great advantages in the scalability of the system, and also provides great convenience for our system development. The reserved station function means that when CC-Link is configured in the network, it can plan to connect to the CC-Link device in the future without hanging up the network. In the network configuration, the system information of these devices (station type, occupied data) is used in advance. The quantity, station number, etc. are registered in the main station, and the relevant programs can be written. After the reservation stations are connected to the network, they can be automatically put into operation without re-configuring the network. Moreover, CC-Link can also operate normally when the reservation station is not connected to the network.
5) Perfect RAS function RAS is an abbreviation of Reliability, Availability, and Serviceability.
The alternate master function, online replacement function, communication automatic recovery function, network monitoring function, and network diagnostic function provide a reliable network system to help users recover the network system in the shortest time.
6) Excellent anti-noise performance and compatibility In order to ensure good compatibility of multi-vendor networks, conformance testing is very important. Usually only the interface part is tested. Moreover, CC-Link's conformance test program includes noise testing. Therefore, all CC-Link compatible products have a high level of noise immunity. As we know, only CC-Link can do this.
In addition to the excellent noise immunity of the product itself, fiber optic cable repeaters provide a more reliable and stable noise immunity to network systems.
No reports have been received about noise-induced system malfunctions.
7) Interoperability and Plug and Play CC-Link provides partners with data configuration documents describing each type of product. This type of document is called a memory map and is used to define the memory cells (addresses) for control signals and data. Then, the cooperative manufacturer develops CC-Link compatible products according to the regulations of this mapping table.
Taking the analog I/O mapping table as an example, the bit data RX0 is defined as a "read ready signal" in the mapping table, and the word data RWr0 is defined as analog data. The same type of products produced by different companies A and B have the same data configuration. Users do not need to consider the difference between A company and company B in programming and use. In addition, if the user switches to the same The types of products of different companies, the program basically does not need to be modified. "Plug and Play" connection device can be realized. 8) Transmitting function CC-Link communication form can be divided into two modes: cyclic communication and instantaneous transmission.
Cyclic communication means continuous data exchange. Various types of data exchange are remote input RX, remote output RY and remote registers RWr, RWw. The data capacity that a substation can pass depends on the number of virtual stations it occupies. Occupying a substation means fitting 32-bit RX and/or RY and redirecting every four words. If a device occupies two virtual stations, its data capacity is doubled.
In addition to cyclic communication, CC-Link also provides instantaneous transmission of information between the primary station, the local station and the intelligent device station. Information is passed from the primary station to the secondary station, and the information data is split in units of 150 bytes and passed in 150 bytes per batch. If passed from the substation to the primary station or other substation, the maximum amount of information per batch is 34 bytes. Instantaneous transfer needs to be done by dedicated instructions.
Instantaneous transmission does not affect the time of cyclic communication.