Cisco FastHub 100 series Installation Manual page 15

rps1 Page 7 Monday, September 14, 1998 8:17 AM
Redundant With Reboot
Figure 1-5 Redundant-With-Reboot Configuration
AC input
AC
AC
DC
DC
DC
DC
Cisco RPS
DC output
External devices
150W or less
AC power cords
AC power strip
In this configuration, one Cisco RPS can support four devices instead of two. Despite
30 seconds of downtime that occur when using redundancy with reboot, this configuration
provides additional redundancy and extends the capacity of the Cisco RPS.
In this way, the Cisco RPS and external device internal power supply can be connected
simultaneously. A sense circuit in the Cisco RPS reads that the device has its AC power
connected and shuts the Cisco RPS output off. In this way competition between the power
supplies is prevented.
Normally, the external device internal power supply always provides power. If the internal
power system of the external device fails, the device powers down briefly until the
Cisco RPS begins supplying power. When the device comes back up, the Cisco RPS is the
main power source.
Overview of the Cisco RPS 1-7