Advantech-DLoG TREK-753, User Manual

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TREK-753 User Manual 4
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5.4 Power Management
5.4.1 Power Management Mechanism
The Power Management feature is provided for users to fulfill special requirements
for different applications.
„
Ignition on/off:
– Turn on the system by ignition
In the case of applications, an ignition signal is often used to turn on or shut-
down the system. When the system is in an OFF state and the ignition is
turned ON, the VPM controller will countdown to ON_DELAY; once it counts
to zero, the system will be turned on.
– Shutdown the system by ignition
When the system is powered on and the ignition is turned off, the
OFF_EVENT_DELAY will start to count down. During this stage, if the igni-
tion is switched back to ON, the VPM controller will stop countdown and reset
the OFF_EVENT_DELAY value. If OFF_EVENT_DELAY counts to zero, the
VPM controller will send an event (power button press) to the system and
start to count HARD_OFF_DELAY. Application programs can watch this
event and do pre-defined tasks, like storing data and preparing to turn off the
system.
Once going into the HARD_OFF_DELAY stage, this process cannot be
reversed. If HARD_OFF_DELAY counts to zero, the system power will be cut
off abruptly.
„
Low power protection:
To avoid draining power, low-power protection is ensures their is enough power
to start the vehicle. When the system is ON, the VPM controller will monitor the
power voltage. If the voltage is lower than the programmable threshold
(LOW_THRESHOLD), the VPM controller will go into LOW_DELAY stage and
start to count down. During the stage of LOW_DELAY countdown, if voltage
goes back above LOW_THRESHOLD, the VPM controller will stop counting
down and exit. If LOW_DELAY counts to zero, the VPM controller will send an
event (power button press) to notify the system, go into LOW_ HARD_DELAY
stage and start to count down. Once LOW_ HARD_DELAY counts to zero, the
VPM controller will cut off the system power abruptly to avoid draining the
power.
The table below lists the user programmable parameters for VPM features:
Default value Acceptable range
ON_DELAY 2 seconds 1 ~ 18000 seconds
OFF_EVENT_DELAY 5 seconds 1 ~ 18000 seconds
HARD_OFF_DELAY 60 seconds 1 ~ 18000 seconds
LOW_THRESHOLD (12V mode) 11.42 V 10.09 ~ 12.25 V
LOW_THRESHOLD (24V mode) 22.44 V 21.11 ~ 23.28 V
LOW_DELAY 30 seconds 1 ~ 3600 seconds
LOW_ HARD_DELAY 60 seconds 1 ~ 3600 seconds