YOKOGAWA CENTUM CS 3000 Integrated Production Control System

SFC Block Functions

SFC Block Functions execute application programs expressed as Sequential Function Charts (SFCs). SFC Blocks are used for large-scale sequence control and device control. Phase progress management (status display) is easy. When an SFC program is created, each program step represents a group of actions. Each step of the SFC may be a sequence table or a SEBOL program (see Figure).

Refer to ltem 3.6.5 for an example of a SFC block display.

SEBOL Functions

SEBOL (SEquence and Batch Oriented Language) is used to write application programs. The I/O from other function blocks (continuous control blocks, sequence control blocks, and calculation blocks, etc.) as well as process I/O data and soft I/O data can be input to a SEBOL block, and computed outputs returned to such function blocks. SEBOL can handle quite sophisticated sequences effortlessly.

Refer to ltem 3.6.4 for an example of a SEBOL program.

Applications of SEBOL:

·Executing multi-phase sequences

To construct instruments which handle complex combinations of sequential control and logical computation

.To communicate with subsystems such as sequencers

To combine sequence processing and data processing

. To create hybrid applications which perform functions that can't be handled by standard function blocks.

5. Subsystem Communication Functions

Recently plant equipment or large motors have increasingly incorporated PLCs for equipment monitoring and automatic operation. In addition, analytical equipment, weighing equipment, and various measuring instruments are being made “intelligent,” and data exchanges through communications prevail over the use of analog or contact signals.

CENTUM CS 3000 systems communicate with subsystems that handle communication data in two ways: using PLCs through an FCS and using an OPC server.

5.1 Communications with Subsystems Through an FCS (Option)

Communication I/O modules and subsystem communication packages are used to handle subsystem data similarly to function block data, as in regulatory control blocks or sequence control blocks, allowing operation monitoring from an HIS. In addition, for a subsystem’s redundancy structure, dual-redundant functions are provided to handle communication data as control data.

5.1.1 Connecting Subsystems

The FCS for FIO and compact FCS for FIO use communication I/O modules that are incorporated in a local node installed in an FCS or incorporated in a remote node installed in a cabinet mounted near the field for connecting subsystems. The FCS for RIO and compact FCS for RIO use a communication I/O module built into an I/O module nest installed in the FCS to connect subsystems. For these connections, RS communications cables (RS-232C modem cables, RS-232C null modem cables, or RS-422/RS-485 cables) or Ethernet cables are used.

5.1.2 Supported Subsystem Communication Packages

To communicate with subsystems, download the optional supported subsystem communication packages into the communication I/O module.

Subsystem communication packages that are supported are:

• FA-M3 communication package (for Yokogawa’s FA-M3 and FA500)

• DARWIN/DAQSTATION communication package (for Yokogawa’s DARWIN and DAQSTATION)

• MELSEC communication package (for Mitsubishi general-purpose MELSEC sequencers)

• MELSEC-A communication package (for Mitsubishi general-purpose MELSEC-A sequencers)

• PLC-5/SLC 500 communication package (for Rockwell Automation’s PLC-5/SLC 500 family of programmable controllers)

• Modbus communication package (for Yokogawa’s STARDOM, Schneider’s Modicon and Yaskawa Electric Corporation’s Memocon-SC)

• Siemens communication package (for Siemens’ SIMATIC S5)

• SYSMAC communication package (for OMRON’s SYSMAC Series)

• YS communication package (for Yokogawa’s YS100 SERIES and YEWSERIES 80)

• YS communication package with direct connection (for Yokogawa’s YS100 SERIES)

• Gas chromatography communication package (for Yokogawa’s gas chromatograph)

5.2 Generic Subsystem Gateway Package (Option)

The Generic Subsystem Gateway (GSGW) package is an operation and monitoring station for subsystems such as PLCs. With its general-use PC platform, GSGW can communicate with subsystems using a general-use OPC DA interface through an OPC server. Subsystem data are assigned to GSGW function blocks, and the assigned function blocks can be operated and monitored from a human interface station (HIS), like FCS.

GSGW is addressed to monitor subsystem data. It does not incorporate control function blocks such as PID blocks and the like.

System Configuration

GSGW is connected to a V net and Ethernet. For OPC servers, PLC supplier or third-party vender servers are used. Connections to an OPC server are classified in two types as given below:

When GSGW is on a PC separate from the OPC server

Connection to the subsystem network is made through an OPC server through Ethernet. PCs for OPC server and GSGW are needed when connecting to multiple OPC servers.

When GSGW and the OPC server are on the same PC

The subsystem network is connected directly to GSGW. Insert an interface card connected to the subsystem network into GSGW.

Summary of Communications with Subsystems