Omron 3G3FV-PDRT1-SIN user manual Network Configuration Overview, Network Components

CompoBus/D Communications Line Design Chapter 2

2-1 Network Configuration Overview

The following diagram shows the configuration of a CompoBus/D Network.

Terminating Resistors								Terminating Resistors
are connected at each			Communications		CompoBus/D			are connected at each
end of the trunk line.			power supply		cables are used.			end of the trunk line.
			24 VDC	Power Supply Tap		Trunk
	Trunk line	Trunk line	Trunk line	or T-branch Tap		line	M Trunk line M Trunk line
T	T	T		T				T

T-branch

T-branch

T-branch

T-branch

Node

Node

T-branch

Tap

Tap

Tap

Tap

Tap

CompoBus/D

Drop line

Drop line

T-branch Tap

Drop line

Drop line

Drop line

M

Node

cables are used.

T

Node

Drop line

Node

Node

Node

M

Node

Drop line

M

Node

T: T-branch connection

M: Multi-drop connection

Node

CompoBus/D cables (5-wire cables) are used for the trunk lines and drop lines.

2-1-1 Network Components

HNodes

There are two kinds of nodes on a CompoBus/D Network: The Master and Slaves. The Slaves connect to external I/O and the Master administers the Network and manages the external I/O of the Slaves. The Master and Slaves can be connected at any location in the Network, as shown in the preceding diagram.

HTrunk/Drop Lines

The trunk line refers to the cable that has Terminating Resistors on both ends. Cables branching from the trunk line are known as drop lines. The trunk line length does not necessarily coincide with the maxi- mum length of the Network. CompoBus/D communications are transmitted through 5-wire cables. The cables come in thick and thin versions.

HConnection Methods

Two methods can be used to connect CompoBus/D nodes: The T-branch method and the multi-drop method. With the T-branch method, the node is connected to a drop line created with a T-branch Tap. With the multi-drop method, the node is directly connected to the trunk line or the drop line. Secondary branches can be made from a drop line. Both of these connection methods can be used in the same Network.

HTerminating Resistors

Terminating Resistors are connected at each end of the trunk line to reduce signal reflection and stabi- lize communications. There are two kinds of Terminating Resistors available: One that is provided with a T-branch Tap and a Terminal-block Terminating Resistor. Use a CompoBus/D Cable when connecting a Terminal-block Terminating Resistor.

HCommunications Power Supplies

To use CompoBus/D, connect a communications power supply to the communications connector of each node with a 5-wire cable. Basically, a communications power supply, internal circuit power supply, and I/O power supply must be provided separately.

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