YOKOGAWA CONTROL FUNCTIONS OF CENTUM CS 1000

YOKOGAWA CONTROL FUNCTIONS OF CENTUM CS 1000

Product Overview

Product positioning: Yokogawa is a distributed control system (DCS) developed for small and medium-sized factories, with the core goal of reducing the total cost of ownership (TCO) for users while balancing high functionality and maintainability

Core design concept:

Integrate the validated high-quality control functions of the CENTUM CS series to ensure control reliability

Strengthen communication capabilities with various subsystems such as programmable logic controllers (PLCs)

Simplify engineering processes, improve on-site equipment compatibility, and reduce application development and maintenance costs through innovative technologies

Core functional configuration

（1） Control Function Architecture

Function category, specific content, and function

The minimum control algorithm unit of the basic control component function block (PID controller, selector, etc.) is used to assemble basic control applications

Expand control functions to adjust control blocks, sequence control blocks, SFC blocks, calculation blocks, panel blocks, cover adjustment control, sequence control, batch control and other diverse requirements

Auxiliary management function unit monitoring function is grouped according to process units to manage function blocks, simplifying control and monitoring operations

Input/output function process, I/O implementation, and signal input/output of general sensors and actuators

Input/output function communication I/O achieves signal transmission through universal communication interfaces such as RS-232C

Status prompt function sequence message, alarm real-time feedback system operation status and abnormal information

（2） Reliability Design

Adopting a synchronous hot standby system and continuing the on-site validated FCS reliability design of the CENTUM CS series

Core advantage: In case of sudden CPU failure during operation, the control can seamlessly switch to the backup CPU without interrupting the control action, especially suitable for batch production processes guided by sequence control

Engineering Efficiency Optimization: FCS Template

（1） Design background

The control application is composed of multiple functional blocks, which occupy different internal resources and CPU loads

FCS memory is limited, and if functional blocks are combined in an unordered manner, professional personnel need to estimate resources and load, which is difficult

（2） Template advantages and classification

Core value: Preset database templates according to user expectations for application scenarios, automatically allocate FCS database resources reasonably, and strictly control CPU load to not exceed the limit

Template types: covering three typical application scenarios of regulation control, sequence control, and monitoring, users can directly choose, greatly simplifying the engineering design process

On site communication flexibility design

（1） Core pain point resolution

To address the issues of dispersed on-site control equipment and diverse data types and communication interfaces, two measures are taken to achieve flexible adaptation:

Specific measures to achieve advantages

Separation of Communication Function and Control Application: 1. Data obtained through communication is stored in the "Communication I/O Area"

2. Control the application to access the area through relative addresses or custom tags

3. The system automatically recognizes data types (integers, floating points, etc.) without the need to modify control applications due to communication protocol changes, reducing engineering complexity

C programming adaptation protocol 1. Develop ready-made communication packages for commonly used protocols

2. Special protocols can be encoded in C language to achieve compatibility with multiple universal communication interfaces and protocols, and adapt to different field devices

Innovative virtual testing function: simulator system

（1） FCS simulator

Operating environment: Windows NT operating system

Core function: Read the control application definitions generated by engineering functions, fully simulate the control actions of actual FCS

Communication mechanism: By simulating internal VLnet communication to achieve interaction with operation monitoring and testing functions, the operation logic is consistent with the actual FCS

Core value: Testing and inspection of control applications can be completed without the need for actual FCS hardware, reducing the cost of building engineering environments

（2） Inter station communication simulator

Design objective: To support control application testing for data exchange between multiple FCS

Working Principle:

Receive all communication data packets sent by the FCS simulator to other FCS

Save the request value of the data setting command and return the preset value when responding to the data reading command

Support viewing and setting return data through a graphical interface

Advantages: Multiple users can carry out system engineering in parallel, improving efficiency without increasing CPU load

（3） Internal operating mechanism of FCS simulator

Modular design: Each FCS functional task is encapsulated as a dynamic link library (DLL) and runs as a thread at runtime

Kernel adaptation: The FCS kernel simulation function is completely consistent with the actual FCS kernel interface, ensuring source code reuse and functional equivalence

Scheduling mechanism: After a thread calls the kernel simulation function, it triggers scheduling (scheduling point) and switches threads through the suspend/resume command of the Win32 API

Interrupt handling: An independent interrupt thread, triggered by a window message, pauses the current task when interrupted, and resumes scheduling after processing is completed

Summary and Future Prospects

Core achievement: Through FCS templates, flexible communication design, and virtual testing capabilities, we have achieved a unified improvement in engineering efficiency, enhanced adaptability of on-site equipment, and high reliability

Future direction: Plan to further expand open interfaces and cross platform features, extend FCS simulator technology to scenarios such as PC direct control processes and gateway function development, and strengthen the gateway application potential of on-site communication functions

Key issues

Question 1: Through which designs does the CENTUM CS 1000 reduce total cost of ownership (TCO)? Please explain from three dimensions: engineering, hardware, and maintenance.

Answer: 1 Engineering dimension: Provide FCS templates (regulation control, sequence control, monitoring), automatically allocate resources, control CPU load, simplify design process; Innovative FCS simulators and inter station communication simulators can complete application testing without actual hardware, reducing the cost of building engineering environments. 2. Hardware dimension: Integrating mature control functions and enhanced communication capabilities of the CENTUM CS series, without the need for additional dedicated communication modules, reducing hardware procurement costs. 3. Maintenance dimension: The communication function is separated from the control application, and there is no need to modify the control application when the protocol is changed; The synchronous hot standby system ensures uninterrupted control in case of CPU failure, reduces downtime maintenance losses, and overall improves system maintainability.

Question 2: How does CENTUM CS 1000 solve the problem of diversified communication of on-site control equipment? What are the advantages of its communication architecture?

Answer: Solution: 1 Adopting a "communication function and control application separation" architecture, communication data is stored in a separate "communication I/O area", and control applications access it through addresses or tags to automatically identify data types. Protocol changes do not affect control applications; 2. Provide commonly used protocol communication packages, special protocols support C language encoding adaptation, and are compatible with multiple interfaces and protocols. Advantages of Communication Architecture: 1 Strong flexibility, adaptable to dispersed and diverse on-site control equipment; 2. High stability, separate design reduces the impact of single module failure on the overall system; 3. Good scalability, supporting quick adaptation when adding or replacing on-site devices in the later stage.

Question 3: How do the FCS simulator and inter station communication simulator of CENTUM CS 1000 work together to achieve full process coverage of virtual testing?

Answer: Collaborative process: 1 Preliminary preparation: Generate control application definitions through engineering functions and import them into the FCS simulator; 2. Single FCS testing: The FCS simulator runs on the Windows NT system, simulating actual FCS control actions, and verifying the control logic of a single FCS by simulating internal VLnet communication and operation monitoring functions, as well as testing function interactions; 3. Multi FCS interaction test: Enable inter station communication simulator, receive cross FCS communication data packets sent by the target FCS simulator, save setting requests or return preset data, simulate data interaction between multiple FCS; 4. Result verification: View data status and set return values through a graphical interface to complete the full scenario testing of the control application. Core value: It can cover the entire process of testing from single FCS to multi FCS collaboration without the need for actual FCS hardware and multiple device networking, greatly improving engineering efficiency and reducing testing costs.