The Netra CP2500 monitors its CPU diode temperature and issues warnings at both the OpenBoot PROM and Solaris OS levels when these environmental readings are out of limits. At the Solaris OS level, the application program monitors and issues warnings for the board. At the OpenBoot PROM level, the CPU diode temperature is monitored.
Typical Cycle From Power Up to Shutdown
This section describes a typical environmental monitoring cycle from power up to shutdown.
Environmental Monitoring Protection at the OpenBoot PROM
The OpenBoot PROM monitors the CPU diode temperature at the fixed polling rate of 10 seconds and displays warning messages on the default output device whenever the measured temperature exceeds the preprogrammed warning temperature or the critical temperature. These values have defaults set by the SMC and can not be changed for the OpenBoot
OpenBoot
Environmental Monitoring Protection at the Operating System Level
Monitoring changes in the sensor temperatures can be a useful tool for determining problems with the room where the system is installed, functional problems with the system, or problems on the board. Establishing baseline temperatures early in deployment and operation could be used to trigger alarms if the temperatures from the sensors increase or decrease dramatically. If all the sensors go to room ambient, power has probably been lost to the host system. If one or more sensors rise in temperature substantially, there might be a system fan malfunction, the system cooling might have been compromised, or room air conditioning might have failed.
