K-WANG



Overview
Yokogawa Electric released a technical report (No. 38) in 2004, focusing on the newly added FFCS compact field control station in the CENTUM CS3000 R3 V3.04 version. As a field control station (FCS) designed specifically for small and medium-sized systems, FFCS inherits the high reliability and advanced functions of large DCS, achieves compactness through a new hardware design, and is compatible with existing uXL systems, supporting low-cost upgrades, enriching the FCS product line of CENTUM CS3000 R3 (including standard, extended, renewable, and highly distributed types).
FFCS Core Features
Specific description of characteristic category
Compact and compatible volume is 1/5 of traditional control units; The external dimensions are consistent with the uXL control system control unit and can be directly replaced, maximizing the reuse of existing assets
High reliability adopts Pair&Spare dual redundancy technology, with no instantaneous switching control in case of failure; System availability reaches 7 9s (99.99999%)
Advanced features with complex control functions equivalent to large controllers, supporting system software reuse (common for small and medium-sized/large factories)
Scalable CPU nodes can install up to 8 I/O modules; Can connect up to 3 extension nodes (directly coupled nodes+remote nodes)
Hardware compatibility is compatible with the I/O module (IOM) and field network I/O module (FIO) of CENTUM CS3000 R3
Hardware configuration details
(1) Overall redundant architecture
FFCS supports full hardware dual redundancy configuration, with core redundant components including processor modules, power units (PW481/PW482/PW484), communication buses (SEN/ESB/ER/V-net), and I/O modules, ensuring that a single point of failure does not affect system operation.
(2) Core hardware components
CPU node
The smallest system core can run independently and can install up to 8 IOM modules;
Scalability: Supports connecting 3 expansion nodes (directly coupled nodes+remote nodes);
Interface module: EC401 (ESB bus coupler) is required to connect directly coupled nodes, and EB401 (ER bus main interface module) is required to connect remote nodes.
CP401 processor module
Redundant design: dual MPU architecture, synchronous computing+cross checking, detecting instantaneous errors;
Hardware Reuse: Integrated with CENTUM CS3000 mature CP345 processor card and SB301 interface card, software compatible;
Packaging form: Modular packaging (replacing traditional card design), built-in nickel hydrogen battery (environmentally friendly alternative to nickel cadmium battery), backup main memory;
Core function: Achieve fault free instantaneous switching and ensure control continuity.
The SEN bus (Serial Exchange Nest bus) is specifically developed for program copying and data synchronization of dual redundant processor modules, with the following key parameters:
Specific specifications of parameter items
Transmission method: synchronous serial transmission
Transmission rate 384 Mbps
Data access size 1-256 bytes (depending on frame structure)
Address space of 32 bits per module (4 GB)
Signal level LVDS (EIA/TIA-644 standard)
Topology point-to-point structure
Redundancy feature standard configuration
Error detection CRC-CCITT (16 bits), idle frame self diagnosis
Live operation support module for live plugging and unplugging
Advantages: Compared to traditional parallel transmission, the signal line and installation area are reduced to 1/10, reducing radiation noise and power consumption.
Other key modules
EC401: ESB bus coupler module, 1 ESB bus port, dual module configuration supports ESB bus redundancy;
V-net coupling unit: integrates V-net data link control and physical layer interface to achieve signal isolation and level conversion;
EB401/EB501: ER bus master/slave interface module, used to connect remote nodes;
SB401: The ESB bus is an interface module used to expand communication between nodes and CPU nodes.

System configuration and connection
Minimum system: Only CPU nodes (including 8 IOM modules) meet basic control requirements;
Expansion system: CPU nodes+up to 3 expansion nodes (directly coupled nodes/remote nodes) to expand I/O capacity;
Connection logic:
CPU node ↔ Directly coupled nodes: EC401 (CPU end)+SB401 (expansion end)+ESB bus;
CPU/Directly Coupled Node ↔ Remote nodes: EB401 (master)+EB501 (slave)+ER bus.
Adaptation scenarios and value
Adaptation scenario: Distributed control requirements for small and medium-sized factories, especially suitable for space constrained and high reliability scenarios;
Upgrade value: uXL system users can directly replace control units, minimize equipment investment, and reuse existing assets;
Technical value: The SEN bus lays the foundation for subsequent FCS functional upgrades (such as greater data synchronization), and the dual redundancy design ensures production continuity.
Key issues
Question 1: How can the FFCS compact on-site control station achieve compact design while ensuring reliability and control functions comparable to large DCS?
Answer: ① Reliability guarantee: Adopting Yokogawa's mature Pair&Spare dual redundancy technology, the processor module dual MPU synchronous calculation+cross validation, no instantaneous switching control in case of failure, system availability reaches 7 9s (99.99999%), consistent with large DCS; ② Functional reuse: Integrate the validated CP345 processor card and SB301 interface card core assets of CENTUM CS3000 on hardware, and universal system software at the software level to ensure consistent complex control functions; ③ Compact implementation: Adopting high-density installation technologies such as BGA packaging programmable devices, 1005 size components, and multilayer boards, multiple traditional card components are integrated into a single modular package, compressing the volume to 1/5 of traditional control units.
Question 2: What are the core technical advantages of FFCS's SEN bus compared to traditional parallel transmission buses? What practical value do these advantages bring to the operation of the system?
Answer: The core advantages and practical value are as follows: ① Transmission performance: With a speed of 384 Mbps, it meets the large data synchronization requirements of dual redundant processors and solves the problem of insufficient transmission capacity of traditional buses; ② Hardware optimization: point-to-point serial transmission, reducing signal lines and installation area to 1/10, reducing hardware costs and space occupation; ③ Stability improvement: Adopting LVDS level standard, with low radiation noise and low power consumption, combined with CRC-CCITT error detection and idle frame self diagnosis function, to improve transmission reliability; ④ Convenient operation and maintenance: supports module live plugging and unplugging, maintenance can be carried out without stopping the machine, reducing the risk of production interruption; ⑤ Compatibility: Inheriting the existing backplane bus software interface, users can use it without additional adaptation.
Question 3: What are the core advantages of upgrading to FFCS for existing uXL control system users? What hardware compatibility issues should be noted during the upgrade process?
Answer: Core upgrade advantages: ① Seamless replacement: FFCS has the same external dimensions as the uXL control unit and can be directly replaced without changing the installation structure, maximizing the reuse of existing assets; ② Performance improvement: Achieve high reliability (dual redundancy) and advanced control functions equivalent to large DCS, meeting higher production requirements; ③ Flexible Expansion: Supports up to 3 expansion nodes and 8 I/O modules, and can be flexibly expanded according to production scale. Compatibility issues to be noted: ① Power supply unit: Use the PW481/PW482/PW484 models specified in the document to ensure power supply matching; ② I/O module: Only compatible with the IOM (I/O module) and FIO (Field Network I/O module) of the CENTUM CS3000 R3 series. It is necessary to confirm whether the existing module belongs to this series; ③ Expansion interface: When connecting expansion nodes, dedicated interface modules such as EC401 and EB401 must be used in conjunction, and other types of interface cards cannot be mixed.
