Rockwell Automation 1785-CHBM ControlNet PLC-5 Hot Backup System User Manual - Manual (Page 127)

Publication 1785-UM024B-EN-P - January 2003
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ControlNet network address The address on the ControlNet network given to each node
(also referred to as the node address). For the PLC-5s in the hot
backup system, the ControlNet network addresses must be
consecutive numbers, with the lower number being odd. For
example, a valid network address pair is 5 and 6.
D
Data Highway Plus crossload A configuration option that allows you to crossload data table
files over Data Highway Plus instead of ControlNet. This may be
desirable when the unscheduled bandwidth of the ControlNet
channel is so busy, that any additional traffic may cause network
problems.
designated primary A feature you configure that, when enabled, causes an automatic
switchover to the PLC-5 with the odd-numbered ControlNet
network address as soon as that PLC-5 is ready to take control of
the system. By default, this feature is disabled.
You can configure this feature via the RSlogix 5 Backup
Configuration dialog; configuration must be complete before
you put the backup system into Run mode.
Note: If there is a difference in how the primary and secondary
PLC-5s are configured, the secondary PLC-5 will assume the
setting in the primary before it completes qualification.
E
equivalence check A feature of the ControlNet hot backup system that provides
periodic comparisons of the contents of various memory
sections within the secondary PLC-5 with those in the active
primary. The result of the equivalence check is provided as
status in the Backup Configuration and Status file. No other
automatic action is taken due to the results of this ongoing
system check.
equivalence mode A feature you configure that, when enabled, requires the
secondary PLC-5 to pass an equivalence check, with no
differences detected, before the secondary can successfully
complete qualification.
This feature allows you to require that the secondary be
equivalent to the primary. You can configure this feature via the
RSLogix 5 Backup Configuration screen. You can modify the
settings for this feature at any time, however it is the setting in
the active primary that dictates how the system will operate.