Psion 2739D-7545MBW, User Manual

Page: 103 / 280

Chapter 4: Configuration
Suspend Threshold and Estimated Battery Backup
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Psion Omnii Hand-Held Computer User Manual
Suspend Timeout
When the Omnii is idle—not receiving any user input (a key touch, a scan, and so on) or system activity
(serial data, an activity initiated by an application, and so on)—the hand-held uses the value assigned in the
Suspend Timeout field to determine when the unit will go to sleep (appear to be off).
When the time in the Suspend Timeout field elapses without any activity, the unit enters suspend state. In
suspend state, the Omnii CPU enters a sleep state, and wireless communication is shut off. The state of the
device (RAM contents) is preserved. Pressing
[Enter] wakes the system from suspend state.
4.20.3 Suspend Threshold and Estimated Battery Backup
The Suspend Threshold adjustment tells the system when to shut down when the battery drains. If you
choose Maximum Operating Time , the unit will run until the battery is completely empty; the RAM is only
backed up for a short period of time. If you choose Maximum Backup Time , the hand-held shuts off with
more energy left in the battery so RAM can be backed up for a longer period of time.
The Estimated Battery Backup is the amount of battery power that has been reserved or set aside to
protect data until a charged battery can be installed in the hand-held. When the battery capacity is depleted
up to the
Estimated Battery Backup reserve specified in the Suspend Threshold menu, the Omnii shuts off
automatically and uses the reserve power to preserve the data stored on the computer. Once the Omnii
shuts down, it cannot be switched on until a fresh battery is installed, or the unit is inserted in a docking
station or cradle.
• Slide the Suspend Threshold button to the right to increase the battery capacity reserved for backup
purposes. Data will be preserved to a maximum of 124 hours.
• Slide the Suspend Threshold button to the left to decrease the power reserved for backup purposes;
this increases the Omnii operating time—the amount of time the unit will operate before shutting
down—but reduces the power reserved for backup purposes to a minimum of 24 hours.
Important: Psion recommends setting the Suspend value to 3 minutes. To further reduce
power consumption, carefully consider the duration of time that the display back-
light is ‘on’ (see
“Backlight” on page 68 ).
Important: Selecting Maximum backup time will reserve approximately 20% of the battery
capacity for memory backup. Once the battery is drained, the system RAM
memory is lost and the unit must cold boot.
In most real-time transaction environments this is not a problem (it only takes a
few seconds to cold boot). Batch transaction environments, where data is not
saved to a non-volatile memory (such as an SD FLASH card), may need to pay
particular attention to this parameter. Psion does not recommend the storage of
any valuable data in system RAM.
The Omnii Windows Embedded CE 6.0 environment does not store any critical
data in RAM (such as the registry or file system).
If your application does not save data to RAM, Psion recommends keeping the
Suspend Threshold setting as low as possible to maximize battery run time.