System architecture ABB Freelance 800F distributed control system

System architecture

Freelance 800F is divided into an operator level and a

process level. The operator level contains the func

tions for operation and observation, archives and

logs, trends and alarms. Open-loop and closed-loop

control functions are processed in the controllers.

The Freelance 800F DigiVis operator level

The DigiVis operator stations use PC hardware, either

standard or industrialized in line with the application,

running under the Microsoft Windows operating

system. DigiVis supports dual-monitor operation,

meaning that two monitors can be used on a single

PC, operated using one mouse and one keyboard.

One engineering station and several operator stations

can be installed at the operator level. The Control

Builder F engineering station is used to configure and

commission the system. Usually, portable equipment

such as laptops, which allow configuration both in

the office and on site, is used. The operator level PCs

can also be used as engineering station. A permanent

connection to the engineering system is not neces sary.

The Freelance 800F process level

At the process level, a Freelance 800F system can

consist of several process stations that are connected

with I/O units. You have the option of running these

process stations either redundantly (CPU redundancy,

fieldbus module redundancy) or without redundancy.

Modular plug-in input/output modules are used in

accordance with the type and quantity of process

signals. With AC 800F, fieldbus-compliant compo

nents such as remote I/O or field devices can be

connected.

System communication

The operator and process levels communicate with

each other via the system bus (based on Ethernet)

with TCP/IP, where you can choose between various

transmission media such as AUI, twisted pair, fiber

optic or coaxial cable. A Freelance OPC server is

available for connecting to higher-level operator

stations (800xA) or other OPC clients. The real-time

process values and alarms from the Freelance sys

tem can be accessed via OPC. A „C“ programming

interface for Windows programs can be used for

external applications that do not use the standard

OPC interface. The DMS-API is used for this.