Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual - Manual (Page 22)

22 Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
Chapter 1 About Enhanced Redundancy Systems
Restrictions There are restrictions that you must consider when using an enhanced
redundancy system. Most of these restrictions apply to all enhanced redundancy
system revisions. Exceptions are noted:
• The 1756-RM2/A or 1756-RM2XT modules can be used only with other
1756-RM2/A or 1756-RM2XT modules. You cannot mix 1756-RM2/A
and 1756-RM2XT modules with 1756-RM/A, 1756-RM/B, or 1756-
RMXT modules.
• Please note that firmware revision 19.052 applies to 1756-L6x controllers
only and revision 19.053 applies to 1756-L7x controllers only.
• You cannot use standard ControlNet and EtherNet/IP communication
modules in enhanced redundancy systems . You must use enhanced
communication modules in enhanced redundancy systems. Enhanced
communication modules contain a ‘2’ in their catalog number. For
example, the 1756-EN2T module.
• The redundant controller program cannot contain these tasks:
– Event tasks
– Inhibited tasks
For recommendations and requirements related to programming the
redundant controller, see Program the Redundant Controller on
page 141 .
• You cannot use the Firmware Supervisor feature available in RSLogix 5000
software in an enhanced redundancy system.
• You cannot use SERCOS Motion or Integrated Motion on EtherNet/IP
in a redundant controller program.
• You cannot use consumed Unicast connections in an enhanced
redundancy system. If you attempt to use consumed Unicast connections,
disqualification occurs and qualification of an unsynchronized redundant
chassis pair is not allowed. You can use produced Unicast connections
consumed by remote consumers.
• You cannot use a 1756-EWEB module, and any functionality specific to
that module, in an enhanced redundancy system.
• You can use a maximum of 2 controllers and 7 ControlNet or EtherNet/IP
communication modules in each chassis of a redundant chassis pair.
• In enhanced redundancy systems, revision 16.081 and earlier only,
EtherNet/IP communication modules cannot execute these tasks:
– Connect to remote I/O over an EtherNet/IP network
– Connect to 1715 Redundant I/O systems
– Use Produce/Consume tags
– Connect to Device-level Ring networks
– Use CIP Sync technology
You can execute the tasks mentioned above in an enhanced redundancy
system, revision 19.052 or later.