User's Manual

Airbus Iridium SATCOM System
165E5733-00 L-3 Aviation Recorders Proprietary
Issue, Rev. 02
21 January 2014
Page 46
6.6 CFDIU Interface
The SDU communicates with the Airbus Centralized Fault Display Interface Unit (CFDIU) over
two ARINC 429 Low Speed busses, (1) input and (1) output as shown in
Figure 6-4.
Figure 6-4 – CFDIU Interface
6.7 Date, Time and Position
The Airbus Iridium SATCOM System uses date, time and position information for numerous purposes,
including information tags attached to various reports and events. Date, time and position information
is provided by the system’s internal GPS.
6.8 RS-232/422 Databus
The Airbus Iridium SATCOM System has four serial ports (transmit and receive). Each port is
software-configurable for RS-232 or RS-422 mode. The speed, data bits, parity, stop bits, and flow
control settings for each port are also software-configurable. See Figure 6-5.
Each serial port is assigned 5 pins on the rear connector. The function of these pins is dependent on
whether RS-232 or RS-422 mode is being used.
Table 6-1 – Serial Port Pin Assignments
RS-232 RS-422 Port 1 Port 2 Port 3 Port 4
TXD Tx- 9E 9J 10C 10G
RTS Tx+ 9F 9K 10D 10H
RXD Rx+ 9G 10A 10E 10J
CTS Rx- 9H 10B 10F 10K
Com Not Used 7J 9A 9B 7K