3 cable length and number of devices requirements – Flowserve MX FOUNDATION Fieldbus Field Unit User Manual
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MX/QX FOUNdaTION Fieldbus Field Unit FCd LMENIM2330-01 – 08/11
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2.6.2.2 Network Cable Connections to Other Network Components
Each FOUNDATION fieldbus network may require some or all of the following components depending
on the application:
• Junction Box/Terminal Blocks
• Connectors
• Power Supplies
• Power Conditioners
• Terminators
• Intrinsic Safety Barriers
• Bridge and Repeaters
For cable connecting information on these components, see the following:
• FOUNDATION Fieldbus Wiring and Installation 31.25 kbits/s, Voltage Mode, Wire Medium AG-140
• Relcom Inc. Fieldbus Wiring Design and Installation Guide
• ANSI/ISA-S50.02, Part 2-1992, Fieldbus Standard for Use in Industrial Control Systems Part 2:
Physical Layer Specification and Service Definition
2.6.2.3 Cable Length and Number of Devices Requirements
The network cable consists of a trunk, segments, and spurs. The trunk is the main connection
between all the devices. A segment is a section of the cable that contains the terminators. A spur
connects to the trunk through a junction box. The following topologies are possible:
• Point-to-point
• Bus with Spurs
• Daisy Chain
• Tree topology
• Combination of the above
Figure 2.15 – Network with Spurs
T
Fieldbus
I/O
Control Highway
DCS
(Host)
Terminator
Junction
Box
Fieldbus Trunk
Spur
Spur
T
Terminator
MX/QX FF
Actuator
MX/QX FF
Actuator
MX/QX FF
Actuator
MX/QX FF
Actuator