High-Availability Chassis Manager (Hcm); Hcm Components - Juniper M10i Hardware Manual

For information about the pinouts for the connectors, see
Pinouts"

High-Availability Chassis Manager (HCM)

The High-Availability Chassis Manager (HCM) works with its companion Routing
Engine to provide control and monitoring functions for router components. The HCM
also displays alarm status and takes PICs online and offline.
Two HCMs are installed into the midplane from the front of the chassis, as shown
in
for the first FPC. The standby HCM provides PIC removal buttons for the second FPC.
The HCM in the slot labeled
RE0
in the slot labeled
NOTE: When HCM mastership changes because of failure, Routing Engine mastership
will change as well. For a description of Routing Engine mastership, see
Engine"
The HCM performs the following functions:

HCM Components

Each HCM (shown in
on page 199.
Figure 1 . The master HCM performs all functions and provides PIC removal buttons
HCM0
. Likewise, the HCM in the slot labeled
RE1 . By default, the HCM in the slot labeled
on page 14.
Monitoring and control of router components—The HCM collects statistics from
all sensors in the system. When it detects a failure or alarm condition, it sends
a signal to the Routing Engine, which generates control messages or sets an
alarm. The HCM also relays control messages from the Routing Engine to the
router components.
Controlling component power-up and power-down—The HCM controls the
power-up sequence of router components as they start and powers down
components when their offline buttons are pressed.
Signaling of mastership—In a router with more than one Routing Engine, the
HCM signals to all router components which Routing Engine is the master and
which is the standby.
Alarm display—If an alarm exists, the HCM displays the alarm condition. For
more information, see
"Alarm LEDs"
PIC removal—If a PIC offline button is pressed, the HCM relays the request to
the CFEB, which takes the PIC offline and informs the Routing Engine. Other
PICs are unaffected, and system operation continues. For more information, see
on page 19.
"PIC Offline Buttons"
Figure 6
Chapter 2: Hardware Component Overview
is paired with the Routing Engine in the slot labeled
is paired with the Routing Engine
HCM1
on page 18.
) has the following components:
High-Availability Chassis Manager (HCM)
"Cable Connector
HCM0 is the master.
"Routing
17