Dip Switch Settings; Power Challenges In A Vehicle Pc - mini-box M4-ATX Installation Manual

DIP Switch (ON=down)
1 2 3
P
OFF OFF OFF
P0
ON OFF OFF
P1
OFF ON OFF
P2
ON ON OFF
P3
OFF OFF ON
P4
ON OFF ON
P5
OFF ON ON
P6
ON ON ON
P7
*AutoLatch is active during the fist 60s of PC operation (and only during the first 60
seconds). For example, If Ignition is turned ON and then OFF right away, M4-ATX will
latch Ignition in ON position for the next 60 seconds, allowing your operating system
to fully come up. This will prevent disk drive corruption or systems that remain hung in
the ON position. After the first 60 seconds of system operation, the AutoLatch feature will
be removed and system will shut down at as governed by the "Off-delay" setting.
P0: In this mode, the M4-ATX behaves like a regular ATX power supply. If J6 is
connected to the motherboard, M4-ATX will also send a gratuitous "ON pulse" to the
motherboard right after power is first applied.
P1 (recommended): Sends ON pulse to motherboard when ignition is ON for more than
5 seconds, sends OFF pulse to motherboard 5 seconds after ignition is turned off. Waits
another 60 seconds and then shuts down 5VSB to conserve battery. In this mode, the
M4-ATX consumes less than 0.5mA. This is our recommended setting.
NOTE: Should you need to reset to factory defaults (in case changes were made via the USB uplink), simply power
off the unit, connect a jumper to JP1 and then apply power back up for more than 2 seconds. The LED light will start to
flash rapidly indicating that the factory defaults were loaded. Don't forget to Remove jumper! Disconnect M4-ATX
from battery for at least few seconds. You are done!
Power challenges in a vehicle PC: One of most difficult tasks of operating a PC in a
vehicle is power consumption while the computer is OFF. Even when your computer is
OFF or in Suspend, it will still consume about 50-150mA on the 5VSB rail. No matter how
big your battery is, you will eventually drain it if proper actions are not taken.
The M4-ATX is addressing these issues by cutting off the 5VSB rail after a pre-defined
amount of time (see jumper chart, HARDOFF). During HARDOFF if the battery level
drops below 11.2V for more than one minute, M4-ATX will shut down and re-activate only
when the input voltage is above 12V.
Engine Cranks, under-voltage and over-voltage situations. Another difficult task is
maintaining stable power to your PC. While car batteries are rated at 12V, they actually
provide voltages in between 8-16V (engine cranks) or as high as 80 volts (load dump).
Most times, your battery will stay at 13.5V but extra precautions need to take place in
M4-ATX User Guide
Off-delay Hard-off
(All rails ON) (5VSB)
Standard PSU mode
5sec + 1min AutoLatch*
1min + 1min AutoLatch*
1min + 1min AutoLatch*
15min
15min
30min
2hour
IMPORTANT: Always use the
"Hibernate" feature, never use
"Standby" as it can severely
discharge your battery over
1 min
extended periods of time.
NEVER
NEVER use "hard-off = NEVER"
1min
settings unless you understand the
1min
risks of battery depletion. Even with
safety limits in place, your battery
NEVER
might be not be able to start your
1min
engine. "Hard-off=NEVER keeps
NEVER
your 5VSB rail on at all times"
Page 3