REDUNDANCY OPTION COMPONENTS
SNAP PAC Redundancy Option User’s Guide
4
controller, and updating redundant variables and I/O values. If neither controller is qualified, the
arbiter favors controller
#1 if both are started up within one second of each other.
•
When a controller is disqualified, the arbiter tells the controller to reset itself.
•
Manages the power supply of each controller using a supply-voltage output to drive
normally-closed relays in the SNAP-RPSW redundant power switch. This allows the arbiter to
reliably restart a controller ensuring that I/O never has more than one master.
SNAP-RPSW Redundant Power Switch
The SNAP-RPSW redundant power switch is a relay device designed
especially for use in a SNAP
PAC redundant system. Connected to
the SNAP-PAC-SRA arbiter and both controllers, this switch responds
to the supply-voltage output from the arbiter. This allows a
controller to be restarted in order to bring the controller back up, or
to re-commission the controller after its firmware has been updated.
PAC Control Professional and PAC
Redundancy Manager
The controllers in a redundant system run a control program built
with PAC Control
™
Professional, one component of PAC Project
™
Professional software. Also included with PAC Project Pro, the PAC
Redundancy Manager provides tools to configure the arbiter, monitor the devices in a redundant
system, install firmware on the arbiter and the controllers, and more.
