beautypg.com

Choosing a backup configuration chapter 1 – Rockwell Automation 1775-MX_S4A,D17756.3.1 User Manual PLC-3 BACKUP CONC(OR.DU1 User Manual

Page 15

background image

Choosing a Backup Configuration

Chapter 1

1-8

Switchover

Method:

Attributes:

Manual

Switchover

Ć When the primary processor faults, the system shuts down as though no

backup system were available.

Ć Operator intervention is required at switchover.

Ć Control of the process is lost until switchover occurs.

Ć Quickly resume control of a process following a fault in the primary

processor.

Ć Easy to transfer between primary and backup processor.

Ć Manual switchovers do not guard against unexpected shutdowns as well as

automatic switchovers do.

Ć We suggest this method for applications using multidrop modems with

1775ĆKA modules.