Rockwell Automation 1756-SYNCH ControlLogix SynchLink Module User Manual - Manual (Page 21)

1 Publication 1756-UM521C-EN-P - July 2004
Chapter
2
Time Synchronization in the
ControlLogix System
This chapter describes how the ControlLogix SynchLink module fits in
the ControlLogix system.
Before you can fully understand how the SynchLink module can be
used in a distributed ControlLogix system, you should understand
how a ControlLogix application works without SynchLink. See the
ControlLogix System User Manual, publication 1756-UM001 for a
detailed description of the ControlLogix system.
Table 2.1
For information on: See page:
Using the Coordinated System Time (CST) 2-2
Time Synchronization in a Distributed Control System 2-2
Time Synchronization in the SynchLink System 2-2
How Do the CST Clock and SynchLink Node Clock Work Together? 2-5
What are the SynchLink Configurations? 2-6
IMPORTANT
In RSLogix 5000, v13 or greater, you can use a
1756-SYNCH module in a remote chassis without a
ControlLogix controller and still provide a CST value
for the chassis. I/O modules (e.g., 1756-IH16ISOE)
can use the CST value when generating timestamps.
For SynchLink systems that use RSLogix 5000, v12 or
earlier, you cannot use a 1756-SYNCH module to
synchronize I/O timestamps in a remote chassis
without first installing a ControlLogix controller in
that chassis.