Z-World Fox LP3500, Руководство пользователя

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20 Fox (LP3500)
Table 2 lists the power modes based on clock frequency that can be defined in software
using the
powerMode
function.
The LP3500 can operate at various power levels, depending on the clock frequency and on
which subsystems on the board are turned off using the
devPowerSet
function. Table 3
lists the LP3500 subsystems that can be turned off with the
devPowerSet
function.
NOTE: RxE always remains active when the above systems are turned off to allow the
LP3500 to “listen” while it is in the
power-save
mode.
The LP3500 processor turns off automatically when VIN is removed, and the processor
will not operate again until VIN is restored. The onboard battery provides backup for the
SRAM and the real-time clock. VIN must be applied to the LP3500 in order to run or set
the processor in any of the numbered modes listed in Table 2.
3.2.1 Setting the Power-Save Mode
The LP3500 can be placed in the power-save mode using one of three different software
calls,
serCommAlert ,
timedAlert , or
digInAlert ,
depending on whether you wish to use Serial Port E, a simple timeout, or a digital input to
trigger the LP3500 to resume operation in one of the other power modes.
If you call
serCommAlert
, then any activity on Serial Port E will trigger the LP3500 out
of the low-power mode. If you call
timedAlert
, then the LP3500 is triggered out of the
power-save mode when the specified time has elapsed. If you call
digInAlert
, then the
LP3500 is triggered out of the power-save mode when the specified channel is activated.
In addition,
digInAlert
and
serCommAlert
have “backup” timeout parameters associ-
ated with them to wake up the LP3500 after a specified period even in the absence of the
digital or serial triggers.
Table 3. LP3500 Subsystems That Can Be Turned Off
LP3500 Section Description
RS-232 Receivers and transmitters are disabled, RxE remains active.
RS-485 Transmitter is disabled.
A/D Converter
(LP3500 model only)
ADS7870 internal oscillator is turned off.
LCD/Keypad Module LCD/keypad module is turned off.
All of the Above All sections are disabled as described above.