What is Fieldbus?

Field bus Foundation defines “Field bus is a digital, two-way, multi-drop communication link among intelligent measurement and control devices.” It is one of several local area networks dedicated for industrial automation.

Modern industries could not survive without information technologies and networks in the 21st century. From production line to enterprise level, digital communication supports all economical and social activities by its latest and powerful technologies. Field bus is a part of it and cannot be separated from others. Field bus is the lowest level in the hierarchy and exchange information with higher-level databases.

We have “standards” to transfer measurement and control data between control room and plant floor. They are pneumatic and 4-20mA electric signals. We have enjoyed their finest features of Interoperability and easy maintenance. Smart communication introduced in mid 80’s opened an era of digital communication, but it had many limitations such as proprietary protocols, slow transmission speed and different data formats.

The idea of fieldbus was proposed to solve such problems. A “standardized” digital communication for industrial automation is changing the production system very quickly.

Fieldbus Benefits

Fieldbus is expected to reduce the life-cycle cost of production line and then total cost of ownership (TCO) of the plant.

Planning Phase : Fieldbus allows you to integrate your plant assets on a single plant automation system on digital communication networks. You can connect devices from multiple suppliers without custom software and these network-based systems allow for smaller control rooms, smaller cabinet rooms and more information productivity.

Installation Phase : Fieldbus offers reduced installation and material cost by replacing the traditional one-to-one wiring scheme with networking or multi-drop configuration, while intelligent field instruments make commissioning and plant startup much faster and less expensive.

Operation Phase : Fieldbus integrates various installations of control functions into one system to effectively optimize control of your plant. In addition, a unified human-machine interface (HMI) is provided for your operation. Function Blocks allow control functions to migrate into field devices allowing control functions to move to the field.

Maintenance Phase : Fieldbus allows for the reporting of self-diagnostics, calibration, and environmental conditions of field instruments without disturbing the plant control. Since it uses intelligent instruments, your stock for spare or replacement instruments can be dramatically reduced. Software packages for asset management are useful to minimize maintenance costs.

Renovation Phase : Enhanced functionality of field instruments is endless. Fieldbus devices are becoming standard off-the-shelf instruments, which make it very cost-effective and easy for you to extend the life of your plant. By simply connecting a new device, you can immediately benefit from advanced functionality. And, upgrade costs can be reduced because network-based systems are modular, which means they are done on-line.

FOUNDATION Fieldbus

Fieldbus is not a product but a technology to make above benefits available to end-users. The following two conditions are necessary to make them come true:

1. Many vendors provide fieldbus instruments.
2. Those devices are interoperable