4.10 Radio Power Management - Datalogic Lynx User Manual

USE AND FUNCTIONING

4.10 RADIO POWER MANAGEMENT

The Lynx's power management allows the user to keep device features powered
while the device is off. The features managed by this feature are: Cellular Data/Voice
and GPS.
The Wi-Fi driver has been measured to consume about 50 µA when
left powered. As a result, Wi-Fi will always be left powered during
suspend. This has the positive effect of substantially reducing the
time required for Wi-Fi to fully resume when the device is powered
NOTE
back on.
When the device is powered off, certain features (such as cellular communications
and GPS
) will remain powered if enabled prior to the device powering off. The
behavior of each feature left powered during suspend is as follows:
−
Power is not removed from the radio.
−
The cellular radio can act as a wakeup source for the CPU. When the CPU
wakes up, the device continues to appear "off", but the device driver running in
the CPU can interact with the radio.
−
Depending on what activity takes place, any feature can optionally decide to
change the system power state from Suspend to On. This would appear to the
user as a wakeup event.
If the user releases the power key in the next 1.5 seconds, the system completes the
shutdown of the CPU and device features will remain powered. If instead the user
continues to hold down the power key for a total of at least two seconds, then the
following pop-up dialog will be displayed:
The user is given five seconds to respond. If the user selects "Yes", then the device,
the cellular radio and GPS receiver are powered off. If the user selects "No", or does
not respond within five seconds, the device will power off, but leave radios running as
they were.
4
89