PACSys
tems™ RX3i DNP3 Outstation User Manual
Section 6
GFK-3103B
June 2020
CPU Performance Calculations
87
Section 6
CPU Performance Calculations
For CPE400/CPL410, this section summarizes on how to estimate CPU sweep time due to Event
synchronization between the ACTIVE & BACKUP Units in the HSB Redundancy System for the
CPE400/CPL410 DNP3 Outstation controllers.
6.1
Impact on CPU Sweep Time due to Event
Synchronization
DNP3 Event Synchronization between ACTIVE and BACKUP units in a HSB Redundancy System requires
the transfer of event data in addition to the user transfer list data, which impacts the sweep time of the
CPUs.
In normal operating conditions, the impact on sweep time due to DNP3 Event Synchronization is
minimal (approximately a few milliseconds). However, if either of the two units is powered down and
one unit accumulates DNP3 events, then the sweep time of the units will experience an increase in time
when the unit powers up. This increase in sweep time is due in part by all the accumulated events that
are to be transferred from ACTIVE unit to BACKUP unit in one sweep cycle. This one-time increase in
sweep time depends on the actual accumulated number of events in the ACTIVE unit. Therefore, the
maximum impact on sweep time can be observed if the accumulated events are equal to the total
number of configured events (maximum possible accumulation).