Use cip sync – Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual User Manual
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Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
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Configure the EtherNet/IP Network
Chapter 4
Use CIP Sync
Beginning with enhanced redundancy system revision
19.052 or later, you can
use CIP Sync technology. CIP Sync technology provides a mechanism to
synchronize clocks between controllers, I/O devices, and other automation
products in your architecture with minimal user intervention.
CIP Sync technology uses Precision Time Protocol (PTP) to establish a Master/
Slave relationship among the clocks for each CIP Sync-enabled component in
the system. A single master clock, known as the Grandmaster, sets the clock to
which all other devices on the network synchronize their clocks.
Consider these points when you use CIP Sync technology in an enhanced
redundancy system, revision 19.052 or later:
• If you enable CIP Sync Time Synchronization in the controllers in a
redundant chassis pair, you must also enable Time Synchronization in the
EtherNet/IP communication modules in the redundant chassis pair so all
devices have a single path to the Grandmaster.
If time synchronization is enabled in any controller in the primary chassis
of a disqualified redundant chassis pair, and no other devices in the
primary chassis have time synchronization enabled, the redundant chassis
pair attempts to qualify. However, in these application conditions, the
attempt to qualify fails.
• While CIP Sync technology can handle multiple paths between master
and slave clocks, it resolves mastership most effectively if you configure the
redundant paths so that Time Synchronization is enabled in only the
minimum required number of EtherNet/IP communication modules.
For example, if your redundant chassis pair has three 1756-EN2T
communication modules and all are connected to the same network,
enable Time Synchronization in only one of the modules.
IMPORTANT
Before you use this enhancement in an enhanced redundancy system, revision
19.050 or later, see these publications for a full understanding of CIP Sync
technology in any system:
• Integrated Architecture™ and CIP Sync Configuration Application
Technique, publication
• ControlLogix System User Manual, publication