DEFSTAN 00-18(PT4)/4(1995) : 1995

Section A. Introduction
1 Scope
2 Discrete signal types
3 Purpose
4 Related documents
5 Definitions
Section B. General requirements
6 Test and operating requirements
7 Form of signals
8 Interface categories and constraints
Section C. Critical timing signalling
9 General
10 Transmitter
11 Receiver
12 Cable
Section D. Non-critical timing signalling
13 General
14 Transmitter
15 Receiver
16 Cable
Section E. Low power switching
17 General
18 Low power switch
19 Switching loads
20 Cable
Section F. Fault detecting, non-critical timing signalling
           interface
21 General
22 Switch element
23 Sensor element
24 Cable
25 Electromagnetic compatibility
Figure 1: Discrete interface for critical timing signalling
Figure 2: Transmitter test circuit
Figure 3: Transmitter waveforms for critical timing signalling
Figure 4: Receiver test circuit
Figure 5: Receiver waveform for critical timing signalling
Figure 6: Discrete interface for non-critical timing signalling
Figure 7: Transmitter waveforms for non-critical timing signalling
Figure 8: Receiver waveform for non-critical timing signalling
Figure 9: Low power switching interface
Figure 10: Discrete interface for fault detecting, non-critical
           timing signalling
Figure 11: Switch element output waveforms
Figure 12: Sensor element operation
Figure 13: Example of interconnection of multiple sensor elements

Describes the electrical characteristics of four types of discrete signal interfaces for use in avionics systems.