Ring Topology Configurations - Rockwell Automation Allen-Bradley SynchLink 1756-DM Series Design Manual

1756-SYNCH
Master
Node
SynchLink

Ring Topology Configurations

The ring topology is a permutation of the daisy chain configuration. In
the ring topology, the end node's transmitter is connected to the
master node's receiver. This topology can include center nodes; the
only difference between the center and end nodes is their physical
location.
Ring Topology Configuration #1
In this configuration, a ControlLogix SynchLink module is the master
node, and ControlLogix SynchLink Drive modules are the center and
end nodes.
Figure 4.8
1756-SYNCH 1756-DMxxx
Center
Node
ControlNet
Table 4.9 lists more information about this configuration.
Table 4.9
Category:
Time synchronization
Data transfer
Restrictions
Typical applications
(1)
The local Logix controller must move the buffered data for a 1756-SYNCH module. For the 1756-DMxxx module,
the module's VPL microprocessor must move the data. For more information, see page 1-7.
1756-SYNCH 1756-DMxxx
Center
Node
Explanation:
Master - 1756-SYNCH module
Slaves - 1756-SYNCH modules and 1756-DMxxx
series modules
The SynchLink node clocks and the CST clocks are synchronized
across all nodes.
The VPL values are synchronized across all 1756-DMxxx series
modules because the modules are synchronized by the respective
CST values in each chassis.
· Typically, this configuration is used to transfer direct data.
· If you want to pass buffered data, the local controller at
each node must pass the data.
· Data can be passed back to the master node.
Axis data is not supported in the configuration.
Progressive draw
Publication 1756-TD008A-EN-P - August 2002
4-13
1756-SYNCH 1756-DMxxx
End
Node
42748
(1)