User's Manual

Airbus Iridium SATCOM System
165E5733-00 L-3 Aviation Recorders Proprietary
Issue, Rev. 02
21 January 2014
Page 31
3.5.7 Discrete Outputs
Each discrete output transitions between an ‘Open Circuit’ (high-impedance-to-ground) and a ‘Closed
Circuit’ (low-impedance-to-ground) state to indicate a change in output logic.
Quantity: 8 Configurable
‘Open Circuit’ Impedance: >100 kΩ
‘Open Circuit’ Voltage (Max.): 36 VDC
‘Closed Circuit’ Current Limit (Min.): 500 mA
Voltage Across ‘Closed Circuit’: <1.25 V
3.5.7.1 Configurable Outputs
The Discrete Outputs use ‘Open-Closed’ signal levels, where the output is either high-impedance to
ground (Open) or low-impedance to ground (Closed). Each configurable discrete output is individually
software-configurable for the following:
 Logic Assignment: Active Low (Closed) or Active High (Open)
 Function: Selected from list.
Refer to §6.11 for additional information on use of configurable outputs.
3.5.8 Two-Wire Phone
Quantity: 2
Format: Standard 2-Wire Tip and Ring Loop
Loop Battery: 48 ±4 VDC
Ring Signal: 20 Hz ±10%, 90 ±10 VAC RMS
Hook Flash: <700 ms
Load Impedance (Nom.): 600 Ω
Polarity Sensitivity: None
Audio Band Pass: 300 – 3400 Hz
3.5.9 Microphone Input
Quantity: 1
Format: Standard DO-214 Microphone Input
Dynamic Range: 20 mV to 1.5 V RMS
Input Impedance: 150 Ω ± 20%
Mic. Bias (No Load): 16 ± 0.5 V
Mic. Bias Ripple: <1 mV RMS in the 300 – 3400 Hz band