The computers with old AT form-factors can be switched off by pressing the flush Power button on the front panel of the system unit. The ATX-units are equipped with a push button. A system may ignore a single clicking on a power button. BIOS is able to solve this problem.
The parameter “Power Button Function” (Power Button Mode) controls the system behavior while pressing the Power Off Button. This parameter may have two values: On/Off – a computer is turned on/off when the trigger is clicked; Suspend – if a computer is on, the trigger activates the power saving mode, and if pressing the button for more than 4 seconds, a system is turned off. The type of the triggered power-saving mode depends on a value set for the parameter “ACPI Suspend Mode”.
In addition to the parameter “Power Button Function”, the following parameters have similar functions for controlling the power On/Off:
- The parameter “Power Button Over Ride” has got two values: Enabled – to switch off the power it is allowed to use the software tools of operating system while mechanical switch-off is achieved only after holding the power button for more than 4 seconds; Disabled – a computer switch-off is achieved by clicking the trigger.
- The parameter “Power-off by PWR-BTTN” (Soft-Off by PWRBTTN) has got two values: Hold 4 Sec (Delay 4 Sec) – when pressing the trigger, the system goes into the power saving mode, and when holding the Power button for more than 4 seconds, the system switches off; Instant-Off – an instant computer shutdown when triggering.
- The parameter “PWR Button < 4 Secs” has got three values: Soft Off – the software tools are available for entering the power saving mode, and a computer is switched on after pressing the power button; Suspend – after pressing the power button, a system enters the power saving mode, and while holding the button for more than 4 seconds, a computer is switched off; No Function – all power-saving mode functions are switched off and the power button operates as a common on/off button.