Rockwell Automation 1756-SYNCH ControlLogix SynchLink Module User Manual - Manual (Page 26)

Publication 1756-UM521C-EN-P - July 2004
2-6 Time Synchronization in the ControlLogix System
What are the SynchLink
Configurations? SynchLink communications are a unidirectional data transfer from one
SynchLink node to another. Each configuration starts with a single
Master Node. The SynchLink network can be configured in the
following ways.
• Star Configuration
• Daisy Chain Configuration
• Ring Configuration
Do not mix the configurations (i.e. begin in the star configuration and
change to the daisy chain configuration). Examples of these
configurations are shown in the following sections.
Star Configuration
The star configuration transfers data from a Master Node through
Hubs to End Nodes.
Figure 2.5
For an example of how to configure a Star configuration, see Appendix B.
Master Node
ControlNet
SynchLink
42747
End Node End Node
End Node End Node End Node End Node
Hub Hub
Hub
IMPORTANT
The star configuration supports 2 layers of hubs with
up to 16 end nodes connected to each hub.
A maximum of 257 SynchLink modules (including
the Master Node) can be connected in the star
configuration.