environmental monitoring

All systems have a large number of sensors that monitor temperature, voltage, and current. The System Controller polls devices in a timely manner and makes the environmental data available. The System Controller will shut down various components to prevent damage.


Field-Replaceable Unit. A discrete part of the system, such as a power supply, a CPU/Memory board or a fan.


Lights Out Management.

LOM prompt

The LOM prompt is the operating environment for the system administrator. It provides configuration control, environmental status, the ability to power on and off the system, the ability to change the System Controller password and access to other System Controller functions.

If POST, the Solaris operating environment, or the OpenBoot PROM is not running and only the System Controller software is running, you can access the LOM prompt, which is lom>.

It also provides a location for console messages to be displayed.


Power-on self-test. This is the program that takes uninitialized system hardware and probes and tests its components, configures what seems worthwhile into a coherent initialized system, and hands it off to the OpenBoot PROM.


The software application that runs on the System Controller and which provides a command line interface for you to modify the system settings.


Serial Eraseable Programmable Read-Only Memory.

System Controller

The System Controller is an embedded system resident on the IB_SSC Assembly which connects to the system baseplane. The system controller is responsible for providing the Lights Out Management (LOM) functions which include power on sequencing, sequencing module power on self tests (POST), environmental monitoring, fault indication and alarms.

virtual time of day (TOD)

The TOD/NVRAM chip is located on the System Controller board. The System Controller multiplexes the physical TOD chip to provide TOD services.