User manual

2U Rack Series User Manual
102
12.2.3 Watchdog Timer Behavior Under Different ACPI States
The Advanced Configuration and Power Interface (ACPI) specification provides
an open standard for device configuration and power management by the
operating system. Table 1 below defines the different states:
Power state
ACPI state
Description
Working
S0
The system is fully usable. Devices that are not in use can save
power by entering a lower power state.
Sleep
S3
The system appears to be off. Power consumption is reduced to
one of several levels, depending on how the system is to be used.
The lower the level of power consumption, the more time it takes
the system to return to the working state.
Hibernation
S4
The system appears to be off. Power consumption is reduced to
the lowest level. The system saves the contents of memory to a
hibernation file, preserving the state of the operating system,
applications, and open documents.
Off State
S5
The system appears to be off. Some components remain powered
so the computer can wake from input from the keyboard, LAN, or
a USB device. The working context can be restored if it is stored
on nonvolatile media.
Table 1: ACPI State Descriptions
Correspondingly, the watchdog timer on IV70 behaves differently under different
ACPI states, shown in the Table 2:
Power state
ACPI state
Watch Dog Behavior
Working
S0
1. Supported
2. Works by having the windows application to set the
watch dog timer. When the system hangs, and the
watchdog timer times out, the watchdog timer notify
the system to shutdown or reboot.
If the watchdog behavior is reboot, please set the
“Restore AC Power Loss” option to “on”. Please refer to
Chapter 11.3.
Sleep
S3
Not Supported
Hibernation
S4
Not Supported
Off State
S5
Not Supported
Table 2: Watchdog Timer Behavior for each ACPI state