User`s guide

10 - 2
Suspend/Resume with GPS
When the terminal goes into suspend mode, power is removed from the GPS module. There are two ways
to control the Suspend/Resume activity of the terminal: via the keyboard or via activity timeout.
Suspend Via Keyboard Combination
Press Blue + Backlight keys.
Suspend Via Activity timeout
Dolphin terminals suspend when the device is inactive for a programmed period of time. This period of
time is set in the Settings -> System -> Power applet; see Power on page 6-12.
A GPS application can prevent this suspend by calls to SystemIdleTimerReset(). For example, to
determine the frequency with which to call SystemIdleTimerReset() in a battery powered situation,
retrieve the following registry value:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\Timeouts\BattSuspendTimeout
This value corresponds to the value set in the Power Applet discussed on page 6-12. For example, if this
value is set to 120 (seconds), an inactive system running on battery power will suspend in 120 seconds
unless a running application calls SystemIdleTimerReset() within the 120 second timeout period.
This function must be used appropriately! Keep in mind that a program that never suspends (or
sleeps) by continually calling SystemIdleTimerReset() quickly drains the battery.
Note: For complete instructions about Suspend/Resume in general, see Resetting the Terminal on page 3-25.
Time to First Fix (TTFF)
The duration of time spent in suspend mode affects the time it takes to acquire a positional fix when the
terminal resumes normal operations. This is known as “Time To First Fix” (TTFF).
Note: When the terminal boots up for the first time from the factory, TTFF can take up to 15 minutes.
Typical TTFF From No Satellite Data
The terminal stops acquiring GPS data when
1. The terminal goes into suspend mode, which can happen manually or due to device inactivity.
GPS data acquisition begins again when the terminal resumes normal operation. You have to wake
the terminal manually by pressing the Scan key. For more information, see Resetting the Terminal
on page 3-25.
2. The terminal moves to a location where it cannot receive satellite signals; inside a building that
blocks satellite reception, for example.
Typical TTFF
Type of Start Start Description Typical TTFF
Cold Start No satellite data has been received for 16 hours 40 seconds
Warm Start No satellite data has been received for 30 minutes 25 seconds
Hot Start No satellite data has been received for 15 minutes 1 seconds
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