Flowserve MX FOUNDATION Fieldbus Field Unit - Manual (Page 14)

MX/QX FOUNdaTION Fieldbus Field Unit FCd LMENIM2330-01 – 08/11
14
The following Figure 2.4 illustrates these four types of network. Details such as power supplies and
terminators are omitted for clarity.
Figure 2.4 – Cable Topologies
2.3 Other Network Components
In addition to the network cable, the following components may be used in the network. Each
network is designed based on its application and therefore may not require all of these components.
• Terminal Blocks. These provide multiple connections to the bus (network)
• Connectors. These make connections to junction boxes, terminators, or other connectors. They
are useful in installations where devices will be periodically disconnected or when a device is only
going to be temporarily disconnected.
• Couplers. These provide one or several connection points to a network segment.
• Terminators. These are used at each end of a fieldbus segment to prevent signal reflections.
Terminators should be placed as far apart as possible.
• Power Supplies/Conditioners. There are four types of power supplies that can be used in a
FOUNDATION fieldbus network, as follows:
1. Non I.S. fieldbus power supply, not intrinsically safe
2. Standard linear or switching power supply used with a power conditioner
3. Fieldbus power supply
4. Fieldbus power supply, intrinsically safe
Fieldbus
Interface
Control Highway
Distributed Control
System (Host)
Junction
Box
Tree
Daisy Chain
Bus with spurs
(or drops)
Point-to-point
Schematic topology: Details such
as terminators and power supplies
not shown