Fieldbus Junction Box for FF H1 or Profibus PA

n process plants throughout the world, segment protectors and FieldBarriers are used as key components in the distribution of feldbus networks from the control room to the feld instruments. A trunk and spur topology is commonly used. In a typical feldbus installation, 10-12 feldbus devices are connected via one cable run that can span between 1500-1900 meters. This one cable supports power and communication to all the devices; therefore, it is recommended to use short circuit protection and energy limitation to isolate a fault condition from negatively affecting device communications on that segment. One device is connected to the output spur of a segment protector or FieldBarrier. Fieldbus junction boxes are installed close to the instruments in the feld in one of two ways depending on the location of the instrumentation: