ADLINK ReadyBoard 910 - Manual (Page 44)

Chapter 3 Hardware
38 Reference Manual ReadyBoard 910
Power and Sleep States
The following information applies to the ReadyBoard 910 only if an ATX power supply is used to provide
power. If a non-ATX power supply is used, the ReadyBoard 910 is controlled only by the Power On/Off
switch on the power supply and the various sleep states are not available.
Sleep States (ACPI)
The ReadyBoard 910 supports the ACPI (Advanced Configuration and Power Interface) standard, which is a
key component of certain Operating Systems’ power management. The supported features (sleep states)
listed here are only available when an ACPI-compliant OS is used for the ReadyBoard, such as Windows
2000/XP. The term “sleep” state refers to a reduced power consumption state, which can be re-started
(awakened), restoring full operation to the ReadyBoard 910.
In these various sleep states, the ReadyBoard 910 appears to be off, indicated by such things as no display on
the attached monitor and no activity for the connected CD-ROM or hard drives. However, when the
ReadyBoard 910 detects certain types of activity (i.e. power button, mouse, keyboard, or LAN activity), it
returns to a fully operational state. The type of activity detected is based on those supported by the
ReadyBoard 910.
The ReadyBoard 910 supports at least four ACPI power states, depending on the operating system used and
its ability to manage sleep states. Typically, the Power On switch is used to wake up from a sleep state, or
transition from one state to another, but this is dependent on the operating system.
• 1st state is normal Power-On (S0).
 To go to a fully powered on state, the ReadyBoard 910 must either be powered Off (S5), or in a
sleep state (S1 or S4), and then the Power On/Off switch is pressed for less than 4 seconds
(default).
 The ReadyBoard 910 can transition from this state (S0) to the various states described below,
depending on the power management capability of the OS and how it is programmed.
• 2nd state is a standby state (S1).
In this state, no internal operations take place except for the internal RTC (Real Time Clock) and the
contents of RAM. This typically includes no activity for the CPU, CD-ROM, or hard disk drives. The
CPU may be active, and the peripheral devices may power down if no signals occur or power to the
device(s) is not provided. The ReadyBoard 910 appears to be off including the Power-On LED.
 Normally, to enter this sleep state, the ReadyBoard 910 must be fully powered on (S0) while the OS
transitions the ReadyBoard into this standby state (S1) under user control.
 To exit this sleep state, typically the power button is used to wake up the ReadyBoard 910 to restore
full operation, including the Power-On LED. Typically, pressing the power switch for less than 4
seconds (default) will restore full operation.
• 3rd state is Suspend to RAM or Standby [Windows] (S3).
In this state, main memory (RAM) and the internal RTC (Real Time Clock) are the only devices where
power is maintained. This state (Suspend to RAM) stores the state of the operating system prior to
shutdown including all open applications and open documents, etc. in main memory. This allows users
to resume their work exactly where they left off just prior to entering this state (S3) when the system
restores power and the contents of main memory.
This state takes longer to restore and uses less power than S1 or S2, but if AC power is completely lost,
the contents of main memory (RAM), including any changes to documents or data stored in RAM
during S3, is also lost.
 To enter the Suspend to RAM (S3) or Standby state, the computer must be fully powered on and the
OS transitions the computer into this sleep state under user control.
 To exit this sleep state, typically pressing the Power On switch for less then 4 seconds (default) will
restore full operation.