Artesyn AXP1440, Инструкция по установке и эксплуатации, Страница: 143 / 156

Shelf Management Alarm Module
AXP1440 Installation and Use (6806800H23U) 141
7.5.2.2 HRI Protocol
In the redundant configuration, the two ShMM-1500R boards communicate through the HRI
by exchanging data packets. The HRI continues to be operational in case of a single
interconnection failure and is able to detect a double failure. The HRI has a redundant
communication path, using four signals. In the case of a single wire permanent failure (the
signal gets stuck high, low or breaks), data packets continue to be transmitted through the
redundant communication path. A short between two of these four signals is considered a
double failure.
7.5.2.3 Ethernet Signals
The ShMM1500R provides two 100BaseT Ethernet ports, identified within the Linux
environment as eth0 and eth1.The eth0 port is cross-connected to the eth0 port on the other
SAM to provide a dedicated high-speed inter-SAM link for the exchange of status and
configuration details. The eth1 port is connected to an Ethernet switch (a Broadcom
BCM5325E), which in turn connects to the base ports of the two hub slots and to the front-
panel RJ-45 Ethernet connector.
The port utilization of the switch is:

TP port 1 to Local hub slot

TP port 2 to Remote hub slot

TP port 3 to Front panel RJ-45)

TP port 4 to ShMM1500R

TP port 5 is not used

MII port is not used
The default state of the Ethernet switch is not to forward packets between ports. The correct
switch configuration for normal operation is to allow ingress from ports 1, 2 and 3 to port 4 and
to allow egress from port 4 to ports 1, 2 and 3. With the exception of routing a port to itself, all
other routes are blocked.