User's Manual

Airbus Iridium SATCOM System
165E5733-00 L-3 Aviation Recorders Proprietary
Issue, Rev. 02
21 January 2014
Page 48
 Monitored
Unused Ethernet ports should be configured as “None.” A “Monitored” port is one where the system
expects an active link and it will generate a fault if the Ethernet link to the external system is not
available. For example, if the SDU is connected by Ethernet to a Class 2 EFB that is routinely turned
off and stowed for take-off and landing, the port should be configured as “Not Monitored” or the
system will generate a fault whenever the EFB is disconnected.
Figure 6-6 – Ethernet Interface
6.10 Discrete Inputs
The Airbus Iridium SATCOM System has 16 Discrete Inputs, of which 14 are software-configurable for
Open-Ground or Open-28V signaling levels, Active High or Active Low logic, and the assigned
function.
6.10.1 Landing Gear Control Interface Unit (LGCIU) Input
Discrete Input No. 1 (Din 1) is dedicated for use as a Landing Gear Control Interface Unit (LGCIU1)
input. When there is only one LGCIU input (i.e. the LGCIU2 function is not assigned to a Discrete
Input; see §6.10.2) and the ‘LGCIU1’ input transitions to the active state, the system is signaled that
the aircraft is on the ground, and the inactive state indicates that the aircraft is in the air.
LGCIU1 (Din 1) is only an Open-Ground input; it cannot be configured as an Open-28V input. A
Hardware Programming Pin (HPP) is provided to set whether the LGCIU1 input is Active High or
Active Low. If the LGCIU HPP pin (J1B-11F) is tied low, LGCIU1 is configured as an Active Low input,
i.e. Ground = On Ground. If the LGCIU HPP pin is connected to ground, LGCIU1 is configured as an
Active High input, i.e. Ground = In Air.
If one of the configurable Discrete Inputs is configured for the LGCIU2 function (see §6.10.2), the
following logic is used to determine the aircraft’s Air-Ground status:
 When the ‘LGCIU1’ discrete input is in the active state (as configured by the LGCIU HPP
strapping) and the ‘LGCIU2’ discrete input is in the active state (as defined by the ICT setting
for the discrete input configured as ‘LGCIU 2’), the aircraft is considered as ‘on the ground.’