06-01-2011, 01:19 PM
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PRESENTATED BY:
SAURABH VARSHNEY
WHAT IS FIELDBUS
Fieldbus is a generic-term which describes a new digital communications network which will be used in industry to replace the existing 4 - 20mA analog signal.
Fieldbus is a digital communication bus line connecting the field instruments with the control system components.
A field instrument is an instrument attached to a process, e.g.: measurement devices, valves, motor starters and alarm switches.
A fieldbus consists of two wires. The digital signal can be transfered as a voltage difference between the wires – or as a current value.
Without fieldbus, each field instrument has to be connected to the I/O of the control system, two wires for each instrument.
FIELDBUS AND IEC61158 STANDARD
International standardization organizations have worked for many years in order to get an agreement on a common fieldbus standard.
In year 2000 it came a document, the IEC 61158 standard, which includes 8 different fieldbuses in the same standard.
The 8 fieldbuses included in this standard are:
ControlNet
FF – H1 (Foundation Fieldbus)
FF – HSE (Foundation Fieldbus)
Interbus
P-Net
PROFIBUS
SwiftNet
WorldFip
ADVANTAGES OF FIELDBUS
REDUCING CABLING
HARDWARE REDUCTION
SIMPLER CONFIGURATION
SIMPLER MAINTENANCE
RELIABILITY
FLEXIBILITY
FOUNDATION FIELDBUS
FOUNDATION Fieldbus is the technological evolution to digital communication in instrumentation and process control.
FOUNDATION Fieldbus is an all-digital, serial, two-way communication system, which interconnects “field” equipment such as sensors, actuators and controllers.
It differs from any other communication protocol, because it is designed to resolve process control applications instead of just transfer data in a digital mode.
Two related implementations of FOUNDATION fieldbus are
H1 (31.25 kbit/s) interconnects “field” equipment such as sensors, actuators and I/O. H1 is currently the most common implementation.
HSE (100 Mbit/s) (High Speed Ethernet) provides integration of high speed controllers (such as PLCs), H1 subsystems (via a linking device), data servers and workstations.
