air
avionics
2. System Interconnects and Interfaces
Connection of the lighting bus to incorrect pins can cause damage to the unit that
will require return to the factory for repair. Ensure that the lighting bus is connected
to the correct pins and does not short to any adjacent pins prior to applying power to
the unit, including the lighting bus.
In aircraft certified for VFR night operations, the lighting bus interface is mandatory.
2.4 Discrete Inputs
A ‘‘NO WARNINGS SWITCH’’ or a ‘‘NORTH UP SWITCH’’ or both can be connected to either
one of the two active-low discrete inputs.
Active-low discrete inputs are considered active if either the voltage to ground is below 2V
or the resistance to ground is below 375 Ohm. These inputs are considered inactive if the
voltage to ground is 9–32VDC.
Pin Name
Pin number
I/O
Switch Input
1.13 or 2.13
In
ATD
·
Installation Manual
·
rev. 3.0
·
2019/05/09
15
