FOUDATION FIELDBUS SYSTEM

FOUNDATION   FIELDBUS

Q. What is FieldBus? 

>   Field Bus is a Digital, Two way, multi Drop dat bus For communication with field instrument. 

                HISTORY OF 

         INSTRUMENTATION

         Pneumatic instruments

         Output 3 to 15 psi

                         |

         Electronic Instruments

          4 to 20 ma ( non smart) 

                         |

           4 to 20 ma dc 

             Hart Smart

                          |

           Wireless Hart

         Wireless instruments

                           |

                 Fieldbus (FF) 

>Fiedbus was first introduced in the year of 1996 by instrument society of Automation. 

> Fieldbus is a one type of communication protocol to communicate with field instruments. 

> Fieldbus is a digital, two way, multi drop data bus fir communication with field instruments. 

> Output of field instruments ( transmitter) is Digital ( not a 4 to 2o ma) 

 > field bus data transfer speed is 31.25 kbps

> like a 4 to 20 ma system, fieldbus is also used two wire for power and signal ( output) but signal is digital. 

> Field bus allows Multiple instruments to use single cable. Single wire pair carries Both power and digital communication signal. 

> Instead of running individual cable in 4 to 20 ma system, fieldbus allow multiple instruments to use single cable. 

> Fielbus use twisted single pair cable. 

>Field cable colour is orange. 

> field bus use fieldbus power supply ( Fbps( that is 24 v dc.