Cabletron Systems 9T122-24 - Manual (Page 25)

3-5
Operation
System Diagnostic Controller
This diagnostic controller is composed of a Z-80 microprocessor and its
supporting logic. The diagnostic controller is designed to control the power-up
sequencing of modules, monitor the 9T122-24 input and output power
parameters, keep watch over the main host processor, as well as monitor the
temperature and control the SMB LANVIEW diagnostic LED. Although the
diagnostic controller and the main host processor can operate independent of
each other if needed, they exchange information about each other’s status and
overall module condition. The information gathered by the diagnostic controller
is available to the network manager via local/remote management and the LCD
located on the environment module. The 9T122-24 has been designed so that in
the event of a diagnostic controller fault, the module will continue to function.
DC/DC Converter
The DC/DC converter converts the 48 VDC on the system power bus to the
necessary operating voltages for its host network services module. The diagnostic
controller controls the operation of the DC/DC converter.
FNB Interface
SmartSwitch 9000 modules are designed with one of two attachment policies. One
allows a module to dual attach to either FNB-1 or FNB-2; the second allows dual
attachment to both FNB-1 and FNB-2. The 9T122-24 have one dual attachment to
the FNB backplane, connecting to either FNB-1 or FNB-2. The module can insert
into the FNB or bypass it. These flexible configuration options make the
SmartSwitch 9000 ideal for networks designed to Bridge/Route multiple lower
speed LANs to FDDI and/or networks designed using an FDDI collapsed
backbone.
i960 Core
The i960 core in the FNB module serves two major functions: it provides the
packet forwarding logic and performs all network management services. FNB
modules can be configured to run as layer 2 bridges, layer 3 routers or as
SecureFast Packet Switches. It is possible to run the bridging and routing options
concurrently, but the SFPS option cannot run with bridging and routing.