ADLINK ETX-PVR - Manual (Page 50)

Chapter 3 Hardware
44 Reference Manual ETX-PVR
Sleep States (ACPI)
The ETX-PVR supports the ACPI (Advanced Configuration and Power Interface) standard, which is a key
component of certain Operating Systems’ (OSs’) power management. The supported features (sleep states)
listed here are only available when an ACPI-compliant OS is used for the ETX-PVR. The term “sleep” state
refers to a low wake latency (reduced power consumption) state, which can be re-started (awakened)
restoring full operation to the ETX-PVR.
In these various sleep states, the computer 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. Normally, when a computer
detects certain activity (i.e. power switch, mouse, keyboard, serial port, or certain types of LAN activity), it
returns to a fully operational state.
The ETX-PVR supports at least five 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 ETX-PVR must either be powered Off (S5), or in a sleep
state (S1 or S4), and then the Power-On switch is pressed for less than 4 seconds (default).
 The ETX-PVR 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 there are internal operations taking place, including the internal RTC (Real Time Clock),
contents of RAM, activity for the CPU, but the external peripherals, such as hard disk drives, CD-
ROMs, and monitor are off. The ETX-PVR appears to be on due to the Power-On LED.
• Normally, to enter this sleep state, the ETX-PVR must be fully powered on (S0) and the OS
transitions the ETX-PVR into this standby state (S1) under user control.
• To exit this sleep state a wake-up event, such as the Power-On switch, is used to wake up the
ETX-PVR and restore full operation, including the Power-On LED. Typically, pressing the
Power-On switch for less than 4 seconds (default) will restore full operation.
• 3rd state is a suspend-to-RAM state (S3).
This sleep state stores your open files and programs in RAM before powering down. In this state there
are no internal operations taking place, except for the internal RTC (Real Time Clock) and low power
level keeping the contents of RAM alive. This includes no activity for the CPU and external peripherals,
such as hard disk drives or CD-ROMs. The ETX-PVR's Power-On LED is off, but the S3 Mode LED is
turned on only when in S3 Mode. This state is only safe as long as you have power to your system. If
power is lost to the ATX power supply or the battery fails, then the contents of RAM is lost, including
any open applications and data files. This state is quicker than S4, but much more volatile.
 Normally, to enter this sleep state, the ETX-PVR must be fully powered on (S0), and the OS
transitions the ETX-PVR into this suspend-to-RAM (S3) state under user control.
 To exit this sleep state a wake-up event, such as the Power-On switch, is used to wake up the
ETX-PVR and restore full operation, including the Power-On LED, but the S3 Mode LED turns
off. Typically, pressing the Power-On switch for less than 4 seconds (default) will restore full
operation.
NOTE Currently, the Power-On switch, Wake-on-Ring, Wake-on-LAN, Wake on RTX
alarm, Wake on PME, and Keyboard/Mouse activity are the only activities that will
wake the ETX-PVR from a powered-down state, such as Standby (S1), Suspend-to-
RAM (S3), Hibernate (S4) and Power Off (S5). However, not all of the listed
activities will wake each sleep state.