Some of the events that can cause a switchover are:

•Hardware failure within the active controller

•Communications failure between the active controller and I/O

•Communications failure on both control network ports of the

active controller

•Removal of the active controller from the carrier

•User request initiated from Diagnostic Explorer

The MQ, MX, SQ, SX and PK Controllers are all capable of

redundancy. For more information on these controllers, refer to

the respective controller product data sheet.

SZ Controllers are also capable of redundancy. For more

information on this controller, refer to the DeltaV SIS Electronic

Marshalling or DeltaV SIS IS Electronic Marshalling product data sheets.