Compaq 850 manual Remote System Alert Support, Aol/Sos

Technical Reference Guide

5.9.3 REMOTE SYSTEM ALERT SUPPORT

These systems provide Remote System Alert (RSA) support for such NIC cards as the 3Com 3C905C-TX NIC card. The RSA function is similar to AOL in that the unit provides, even while powered off, system status alert messages to a network console. However, NIC cards implementing the RSA method do not use the SMBus for receiving alert information and therefore require, in addition to the PCI connection, an auxiliary AOL/SOS cable connection with the system board (Figure 5-13).

NIC Card in PCI Slot

AOL/SOS Cable

Network Cable

AOL/SOS Header P12

System Board

Figure 5-13.Remote Sense Alert Implementation (Generic Representation)

In the Remote Sense Alert implementation, a NIC card receives event notification directly from the system’s thermal sensors and the LPC47B357 I/O controller over an AOL/SOS cable connection (Figure 5-14). During system-off conditions the NIC card receives auxiliary power from the 3.3 VDC auxiliary power rail on the PCI bus.

47B357 I/O Cntlr.

Thermal

ASIC

System Board

BIOS Fail

NC OS Fail

NC Intrusion

NC Fan Alert

NC Pwr Alert

Thermal

PCI

Bus

NIC Card

AOL/SOS
Header 1	SOS

7

PCI

Connector

PCI

Bus

Figure 5-14.RSA Logic, Block Diagram

Compaq Deskpro EXS and Workstation 300 Personal Computers 5-35

Featuring the Intel Pentium 4 Processor

First Edition - December 2000