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

1756-SYNCH
Master
Node
SynchLink

Daisy Chain Topology Configurations

In the daisy chain topology, the SynchLink system starts at the master
node and ends at an end node but may also include center nodes that
receive and transmit data; the only difference between center and end
nodes is their physical location.
Daisy Chain Topology Configuration #1
In this configuration, a ControlLogix SynchLink module is the master
node, and ControlLogix SynchLink or Drive modules are the center
and end nodes.
Figure 4.4
1756-SYNCH 1756-DMxxx
Center
Node
ControlNet
Table 4.5 lists more information about this configuration.
Table 4.5
Category:
Time synchronization
Data transfer
Restrictions
Typical applications
(1)
The local ControlLogix 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.
· Axis data is not supported in the configuration.
· A 1756-SYNCH module must be the time master.
· A 1756-SYNCH module is required in each chassis to
synchronize the CST. The Drive modules then synchronize
their VPLs with the CST.
· You can use a maximum of 10 SynchLink connections.
Multi-Section Drive Synchronization
Publication 1756-TD008A-EN-P - August 2002
1756-SYNCH 1756-DMxxx
End
Node
(1)
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