Configure Redundancy

Redundancy is the use of two or more controllers, each carrying out the same function, to improve reliability or availability. Use the
Controller Properties
dialog box
Redundancy
tab to configure the redundancy features of a controller.
WARNING:
When using redundancy with an Equipment Sequence, sequence execution may not be as expected after switchover if the phase and sequence are not scheduled on the same task. With redundancy enabled, Equipment Sequences are supported only on 1756-L8zP controllers.
To configure redundancy:
  1. Select
    Redundancy Enabled
     to enable the redundant features of the controller.
    TIP:
    This option cannot be changed if the controller is online, but the redundancy state is still visible.
  2. Review the remaining information provided on this dialog box.
    The other parameters provide information regarding the status of the connected controller, the status of the partner module, and any minor faults that are set in the partner controller.
  3. Select
    Advanced
    to access the
    Advanced Redundancy Configuration
     dialog box, to configure additional redundancy features.
IMPORTANT:
Motion is not supported with redundancy. Delete motion groups, axes, and coordinate systems when redundancy is enabled.
These additional components are not supported with redundancy:
  • Embedded controller Ethernet port
  • Event tasks
  • Inhibited tasks
  • License Source Control
  • Unicast connections
  • Safety partner in a redundant chassis
  • Produced safety tags
  • Consumed safety tags
  • OPC UA Access
  • Non-concurrent safety connections
  • HMIBC tags and instructions
  • Match Project to Controller
     feature
  • With redundancy enabled, Equipment sequences are supported only on 1756-L8zP controllers
  • Bumpless output connections controlled by IOT instructions
  • Listen Only or Input Only connections for FLEX 5000 I/O or devices that utilize Highly Integrated Hart from a redundant controller (There is no ability for another controller to create listen only or dual-own for these types of connections.)
TIP: When Redundancy is turned on, the safety task must have the highest priority, for example, 1.
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