Developers guide

Chapter 6: Power Management
Controlling Power Through The SDK
42 Psion Teklogix Mobile Devices SDK Developers Guide
6.2.2 Controlling Power Through The SDK
Each of the API libraries has methods for the following (refer to the documentation for the rele-
vant API library for more details)
Querying The Power State
When the power state of a card slot is queried, the result is interpreted as follows:
• PowerState_Off — returned when there is no card in the card slot, or when there is a card in
the slot and the card slot is powered down.
• PowerState_On — returned when there is a card in the slot and the card slot is powered on.
• PowerState_Unknown — returned when the power state of the slot cannot be determined.
Changing The Power State
When a slot is in PowerState_On, it is powered down by one of the following:
• Using the SDK method for setting the power state.
• Through the Windows Control Panel.
When a slot is in PowerState_Off, it is powered up by one of the following:
• Using the SDK method for setting the power state.
• Through the Windows Control Panel.
• Performing a clean start of the Windows operating system (see Section 1.5: “Resetting
Psion Teklogix Computers”).
Events
If there is a card in the card slot when the power state is changed, the following events are
generated:
• Changing the state from PowerState_On to PowerState_Off generates a card removal event.
• Changing the state from PowerState_Off to PowerState_On generates a card insertion event.
While the card slot is in PowerState_On, the following events occur:
• Inserting a card generates a card insertion event.
• Removing a card generated a card removal event.
While the slot is in PowerState_Off, no card insertion or card removal events are generated.
Method Purpose Input & Output
Set the power state Input: <Hardware name> and <Power state>
Get the power state Input: <Hardware name>
Output: <Power state>
Where: <Hardware name> identifies the card slot. See “Card Slots” on page 39
for valid values.
<Power state> has one of the following values:
PowerState_Off
PowerState_On
PowerState_Unknown (only valid when querying the power state)