MoTeC ACL VIM - Manual (Page 30)

26 Operation
Switch Inputs
Available on: ADL2, SDL, E888, E816
Switch inputs are generally used for the external toggle switches or
press buttons.
Switches are typically used to operate features such as Change Display
Mode, Alarm Acknowledge, Fuel Used Reset and other similar
functions. They can also be used to monitor items such as brake status.
Normally the switch inputs have a pull-up resistor connected internally
from the input pin to the 12 V or the 5 V sensor supply. This allows a
switch to be connected between the input pin and 0 V, so that the input
is pulled to 0 V when the switch is closed.
Digital Inputs
Available on: VIM, ADL2, SDL, E888, E816
Digital inputs are identical to the switch inputs, except that they include
the ability to measure frequency, period or pulse width.
Note Not all these measurement methods are available on all input
devices, for example the E888 can only measure frequency.
Speed Inputs
Available on: VIM, ADL2, SDL
Speed inputs are similar to the digital inputs, except that they can also
be configured to suit variable reluctance (magnetic) sensors such as
some wheel speed sensors.
Because the amplitude of the signal from these sensors varies with
speed of rotation, variable trigger levels are required, which must vary
with the frequency of the input signal.
The speed inputs can also be used with Hall Effect (open collector
output) type wheel speed sensors.
Note It is possible to monitor the voltage of the input signal directly as
well as reading the speed. While not intended for precision
measurement, this is especially useful when setting magnetic sensor
levels, where the measured voltages on the pin can be used to set the
trigger voltages.