Structure and application of CC-link fieldbus

Integration of fieldbus control and information processing CC-Link (Control and Communication Link) is a province of wiring and information networks, it is not only highly real-time, distributed control, with smart device communications, RAS features, and rely on strong links with many equipment manufacturers, provide an open environment. Q Series PLC modules CC-Link QJ61BTll, in the A/QnA series of skills at the same time, also used the remote handy features such as device initialization.

In order to use a variety of equipment directly connected to the CC-Link on, with numerous equipment manufacturers at home and abroad to establish a partnership, enables the user to easily select a field device, an open network. In October 2000, Woodhead, and Contec, Digital, NEC, and Panasonic Electric, Mitsubishi, 6 Executive member companies launch, Japan has set up an independent nonprofit institution “CC-Link Association” (CC-Link Partner Association, referred to as CLPA), aimed at the effective promotion and popularization of CC-Link technology on a global scale. In December 2001, members of the CLPA amount to more than 230 companies, with more than 360 compatible products.

1. CC-Link composition

CC-Link system at least 1 main station, you can connect remote I/O, remote equipment stands, a local station, the main station, intelligent equipment total 64 stations. CC-Link station type as shown in table 7-5.

Table 7-5 CC-Link station type

CC-Link

Type of station
Content

Master station
All stations on the control CC-Link, and set the parameters. Each system must have a 1-master. Such as the A/QnA/Q Series PLC

Local station
CPU module can communicate with the main station and the other local stations.

Such as the A/QnA/Q Series PLC

Standby master station
If a failure occurs at the primary site, replaced as the primary station, and as a station master to continue the data link.

Such as the A/QnA/Q Series PLC

Remote I/O stations
Can only deal with one bit of information, such as remote I/O modules, solenoid valves, etc

Remote device
To deal with information and information station, such as a/d and d/a conversion modules, inverters and other

Smart devices
To deal with information and information, but also complete data transfer station on a regular basis, such as the A/QnA/Q Series PLC, HMI, etc

CC-Link systems can be equipped with multiple repeaters, in case of not reducing the communication speed, extended range, maximum of 13.2km. For example, you can use the optical Repeater, in maintaining the speed of 10Mbps case, extended the total distance to 4300m. In addition, t-Repeater to complete t-connection, more suitable for connection requests.

2. CC-link communication mode

(1) circulating communications CC-Link broadcasting loop communication. In the CC-Link system, main station, local station data area with remote I/O stations, remote device stations, correspond to the smart device, and remote remote input and output data register will be automatically refreshed. Also, because the main station to the remote I/O stations, remote device, smart device station information will be transferred to other local stations, so local stations can also learn about remote stations.

(2) CC-Link the link element per CC-Link system for a total of 4,096 points, plus totals of 512 words cycle of data communication via these linked elements to complete the remote I/O, analog modules, interface, inverter and other FA (industrial automation) equipment products for high-speed communications.

CC-Link remote input link element (RX), remote output (RY), remote registers (RWw) and remote registers (RWr) four, as shown in table 7-6. Remote entered (RX) is from remote station to main station entered of open/shut signal (bit data); remote output (RY) is from main station to remote station output of open/shut signal (bit data); remote left-device (RWw) is from main station to remote station output of digital data (Word data); remote left-device (RWr) is from remote station to main station entered of digital data (Word data).

Table 7-6 link components list

Project
Specifications

The CC-Link system

Maximum number of links
Remote inputs (RX)
At 2048 o ‘ clock

Remote output (RY)
At 2048 o ‘ clock

Remote registers (RWw)
At 256 o ‘ clock

Remote registers (RWr)
At 256 o ‘ clock

Each site link points
Remote inputs (RX)
At 32 o ‘ clock

Remote output (RY)
At 32 o ‘ clock

Remote registers (RWw)
At 4 o ‘ clock

Remote registers (RWr)
At 4 o ‘ clock

Note: each station according to its station in the CC-Link type, defined as 1, 2, 3 or 4 stations, namely traffic for the table 3-35 in the “links to each station number” 1 to 4 times.

 

(3) the instantaneous transmission in communication CC-Link, in addition to auto-refresh loop communications, you can also use the instantaneous transfer, as a way of sending and receiving information on a regular basis. Instantaneous can deliver traffic from the main station, local stations, smart device, you can make the following:

L) a PLC standing data read and write another soft PLC station components.

2) master PLC for smart devices to read and write data.

3) GX Developer software to another PLC program can be read/write or monitoring.

4) host PC devices such as read and write a soft component data from PLC station.

3. Features of CC-Link

(1) communication communication speed CC-Link to achieve the industry’s highest speed (10Mbps), ensures that required high speed response of the sensor input and large-capacity data communications between intelligent devices. Can select the most suitable for a system of communication and total distance shown in table 7-7.

Table relationships 7-7 CC-Link communication speed and distance

Communication speed
10Mbps
5Mbps
2.5Mbps
625kbps
156kbps

Communication distance
≤100m
≤160m
≤400m
≤900m
≤1200m

Note: through a Repeater to extend the communication distance

(2) high-speed link scanning in only the main station and the remote I/O systems, by setting for remote I/O network mode method, link scanning time can be shortened.

System remote I/O stations on the table 7-8 to all the remote I/O network mode and there are various types of systems used by the remote network mode (normal mode) link to comparison of scanning time.

Comparison of table 7-8 link scan time (communication speed is 10Mbps)

Station number
Link scan time/Ms

Remote I/O network mode
Remote network mode (normal mode)

16
1. 02
1. 57

32
1. 77
2. 32

64
3. 26
3. 81

(3) the alternate main function when using an alternate main function, when the main station when an exception occurs, standby master station over as the primary station, data link network continues. And during operation at the main station, the original master is restored, you will serve as an alternate host to return to the data link. In this case, if you run the main station when an exception occurs, the standby master station data link also will take over as the primary station to continue.

(4) automatic start function in CC-Link only the primary station and remote I/O systems, set network parameters if you do not, when powered up, or automatically start data link. Default parameters for 64 remote I/O stations.

(5) the remote device initialization functions using GX Developer software without writing sequential control program, you can complete the handshake signals control, set of initialization parameters initialize the remote device.

(6) that interrupts program start (interrupt) when receiving data from the network, setting when the condition is true, you can start interrupt programs of the CPU module. Therefore, you can meet the requirements of high-speed processing system. Breaks starting condition of the program, you can set up 16.

(7) operated remotely by connecting a PLC in the CC-Link station on the GX Developer software to other PLC remote programming on the network. Also available through specialized peripheral devices connection module (as a smart device) to complete the programming.

 

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