Abstract: This paper introduces a novel implementation of the CC-LINK remote station system. Remote device stations and remote I/O stations are constructed using CC-LINK remote station control chips MFP3 and MFP2, along with a microcontroller. Based on this scheme, a remote device station module for ink volume control in printing presses and a general-purpose remote I/O station module were developed. The paper describes the hardware and software implementation of the remote device station in the ink volume controller, as well as the hardware implementation of the remote I/O station. Keywords: CC-LINK, remote station, remote device station, remote I/O station, ink volume controller Research and Implementation of CC-LINK based Remote-Station System Abstract: This paper presents a new implementation of the CC-LINK (a new Field Bus) based remote-station system. It uses the CC-LINK remote control ICs MFP3 and MFP2 and an MCU to build the CC-LINK remote device station and remote I/O station. An application of the remote device station in a printing machine and a universal remote I/O device are designed. This paper mainly discusses the hardware and software implementation of the remote device station and the hardware implementation of the remote I/O station. Keywords: CC-LINK, Remote Device Station, Remote I/O Station, printing machine. 1. Introduction Currently, fieldbus applications are increasingly common in industrial control. CC-LINK, as a new type of fieldbus, has high real-time performance. It can connect with smart devices and products from various field device manufacturers, exhibiting strong compatibility and a maximum transmission speed of 10Mbps. It fully meets users' stringent requirements for open architecture and reliability, and has seen increasing application. However, dedicated CC-LINK modules are costly and lack flexibility in building remote device stations. To address these issues, this paper proposes a CC-LINK network construction scheme that combines a basic CC-LINK network with independently designed CC-LINK remote device stations and remote I/O stations. This scheme uses the CC-LINK remote device station control chip MFP3 and the remote I/O station control chip MPF2 to form the CC-LINK network communication part (compliant with CC-LINK communication specifications). Based on field control requirements, field control circuits and input/output circuits are independently designed in conjunction with a microcontroller system. These two parts constitute a highly flexible remote device station module and remote I/O station module based on the CC-LINK network. Each module is connected to the master station module via a dedicated CC-LINK cable, and the master station module is connected to the PLC. Based on the above construction model, flexible remote stations based on CC-LINK can be quickly built without excessive reliance on dedicated CC-LINK modules, saving on the cost of using the CC-LINK system. 2. CC-LINK Network Composition A CC-LINK network mainly consists of a CC-LINK master module, a PLC, remote device station modules, and remote I/O station modules. The network structure is shown in Figure 1. The PLC module checks the CC-LINK network information from the master module and sends corresponding control information to the master module according to system functional requirements. The master module controls the entire CC-LINK network, is responsible for its operation, and acts as the connection module between the CC-LINK network and the PLC. It receives data information from remote station modules and transmits it to the PLC controller, and receives control information from the PLC controller and sends it to the remote station modules through the CC-LINK network. Connecting multiple CC-LINK networks controlled by PLC modules together forms a simple distributed system. A CC-LINK network can connect up to 64 memory stations. The network transmission speeds are: 156Kbps, 625Kbps, 2.5Mbps, 5Mbps, and 10Mbps. It can meet the requirements of high real-time performance. 3. Hardware Structure of Ink Volume Controller This system is mainly used for ink volume controllers in printing presses. Each ink volume controller is responsible for the positioning control of all motors in one color group. It collects the current position information of the ink fountain motors, completes communication with the master station PLC, and completes the positioning of the ink fountain motors according to the control information of the master station. The system controls the positioning of 32 ink fountain motors, and the acquisition, processing, and output control time of the positioning information of all motors is controlled within 5ms. This system belongs to CC-LINK remote device station and is built with P89C51RD2 and MFP3 as the main control devices. It consists of CC-LINK network control part, MCU control part, and input/output circuit. The structural block diagram is shown in Figure 2. MFP3 is the CC-LINK remote device station control chip, which can be connected to sensors, A/D, D/A modules, digital controllers (such as microcontrollers), etc., and communicates digital data and on/off data with the master station, with high flexibility. P89C51RD2 is an enhanced 51 series microcontroller produced by PHILIPS. The system integrates a WatchDog, configurable in 6 CLK and 12 CLK modes. The 6 CLK mode is used to improve the microcontroller's processing speed. 3.1 MCU Control Module: The MCU control module is responsible for the initialization and read/write operations of the MFP3, the acquisition and processing of the inkwell motor positioning information, and the output of motor control quantities. The A/D section uses a high-speed parallel A/D converter MAX1090 to acquire positioning information from 32 inkwell motors. Each inkwell motor is driven by a dedicated motor driver chip. Each motor corresponds to two control bits, controlling forward and reverse rotation. The microcontroller writes the motor status information (position information, alarm, completion) to the corresponding data register of the MFP3 and reads the control information sent by the PLC (position setting, alarm deactivation). Through 64-bit output, it controls the forward and reverse rotation of the 32 motors to achieve motor positioning control. The microcontroller control system can be expanded and designed according to actual functional needs, such as adding keyboards and displays to enhance human-machine interaction. It can also be configured on-site to improve CC-LINK flexibility. 3.2 CC-LINK Network Control Module The CC-LINK network control module mainly consists of an MFP3 and some peripheral control circuits. The peripheral circuits include: a 485 bus driver section, transmission baud rate setting, station number setting, memory station number setting, a system status display module, and a bus connection section with the microcontroller system. The structure diagram is shown in Figure 3. The MFP3 has a bus interface and can connect to intelligent devices such as A/D/A modules and microcontrollers for word data transmission. The basic unit on the CC-LINK network is a memory station. One memory station can perform (32 bits + 4 words) of data transmission, and each remote device station can be configured with a maximum of 4 memory stations. A maximum of 64 memory stations are allowed to connect to the entire network. All devices on the CC-LINK network need to be configured with a unique network address based on their own memory stations. The system will report an error if there are duplicate addresses on the network. The baud rate setting section is used to set the transmission speed. The status display section is responsible for displaying the operating status of the CC-LINK network. CC-LINK networks can automatically detect network operation status, such as network address conflicts, transmission baud rate mismatches, and network disconnections, and display these statuses through RUN, ERROR, SD, and RD signals. When a fault occurs, the CC-LINK fault manual can be consulted for troubleshooting. The CC-LINK network transmission protocol is handled by the MFP3's internal hardware. After initializing the MFP3, word and bit data can be read and written according to its control methods. The MFP3 actively receives refresh cycles from the CC-LINK master module, enabling data transmission between them. 4. Software Design The software design of this ink volume controller mainly consists of two parts: the MFP3 part and the A/D part. The system main program flowchart is shown in Figure 4. Normal Operation includes A/D acquisition, control output, and some logical operations. The rest are related to MFP3 software design. Due to space limitations, only the MFP3 part's software design flowchart is described below. The MFP3 internally contains special function registers and data storage registers (RX, RY, RWw, RWr). MFP3 initialization, refresh, and read/write operations can be achieved through read and write operations on these registers. The main functions are: ■ bit CC_set_timeout(bit is_normal) ■ void CC_init(unsigned char *CC_buf) ■ void CC_frame_write(unsigned char start_addr, unsigned char *buf, unsigned char num) ■ bit CC_frame_read(unsigned char start_addr, unsigned char *buf, unsigned char num) ■ bit CC_poll() The MFP3 write operation flowchart is shown in Figure 5, and the read operation flowchart is shown in Figure 6. 5. Remote I/O Station The remote I/O station module consists of the remote I/O station control chip MFP2 and some peripheral circuits. It collects input I/O signals and outputs I/O signals. The remote I/O station module can only communicate with the master station module for on/off data. It can be connected to sensors and other digital output devices. Its structural block diagram is shown in Figure 7. The 485 bus driver section of the remote I/O station control chip MPF2 is roughly the same as that of MFP3. However, MFP2 only contains one memory station. It allows a maximum of 32 bits of I/O signal data transmission. The system can configure the number of input and output I/Os through hardware. It can be configured as all 32 outputs, all 32 inputs, or 16 inputs and 16 outputs, etc., and has input and output status display functions. The system input is active high and the output is active low. The configuration of station number, baud rate, and 485 bus driver section is the same as the relevant configuration of MFP3, and will not be repeated here. MFP2 accepts the refresh cycle of the master station module, and the data transmission with the CC-LINK network is completed by hardware. 6. Conclusion This paper proposes a flexible and low-cost construction mode for the CC-LINK network. Based on this, the CC-LNK remote device station module was designed, and the hardware and software design were completed. It was applied to the ink volume controller inside the printing press, and the performance was good, achieving the expected results.