41
(5) Virtual off (wireless standby)
Virtual Off is a wireless standby state due to low power consumption. To the user, the unit behaves
as if it is off (suspended). Internally, the terminal is running normally but it seems to be turned off
(suspended) - nothing is displayed and you cannot make key inputs. This function is mainly used to
enable the terminal user to resume communication quickly, while also saving power in
communications standby state. It saves power during standby for wireless communications etc. by
turning the LCD, keys, and touch panel off through an API from an application.
- Summary of virtual off operation
The system takes the status illustrated below. The system has a mode named Virtual OFF and the
state transitions from the ON State to the OFF State in this mode.
The transition is triggered by the message issued by pressing the Power key.
- How to set Virtual Off mode from an application
Use the system library to change to Virtual Off mode. In this mode, the following messages are
displayed alternatively every time the Power key is pressed.
When the Power key is pressed to turn off the power:
WM_POWERBROADCAST (PBT_APMSUSPEND)
When the Power key is pressed to turn on the power:
WM_POWERBROADCAST(PBT_APMRESUMESUSPEND)
In the diagram in Figure 2.11, the application receives PBT_APMSUSPEND message at the first
press of the Power key and then changes the state to Off State in the Virtual Off mode. And then
the application receives PBT_APMRESUMESUSPEND message and returns to the on State of
the Virtual Off mode.
The application undertakes the transition process to the Off state in the Virtual Off mode. The
application disables display, key input, and touch panel operation, etc. and turns off the power to
unnecessary devices.
[Note] For details, refer to the System Library Manual.
To Next Page
Loading...
Need help?
General