User's Manual

Model 1150A DVOR
Rev. - November, 2008
This document contains proprietary information and such information may not be disclosed
to others for any purposes without written permission from SELEX Sistemi Integrati Inc.
2-39
Figure 2-14 Interface CCA Block Diagram
2.3.2.12.1
Interface CCA Detailed Theory
Refer to Figure 11-8. The Interface CCA provides interface connections between the Backplane CCA and the
outside world. All signals are protected by transient voltage suppression (TVS) devices. All connections between the
Interface CCA and the Backplane CCA are accomplished via headers J1 and J2. The J2 and J3 connections will not
be used in a VOR system since there will not be a TACAN antenna system controller.
On-board sensor U1 provides interior (cabinet) temperature while an exterior sensor can be interfaced via RJ11
connector J7. Interior temperature sensor U1 is TVS-protected by diode CR68 while the exterior temperature signal
is protected by diode CR29. Earth or chassis ground is connected by lug E1 and inductor L1. Circuit or analog
ground is accessible at test points TP4 and TP5.
The +24VDC power, which originates at the Facilities CCA, is indicated present by LED CR71 and resistor R30.
The +24VDC is TVS-protected by diode CR44 and available to be measured through resistor R28 and test point
TP3. The +24VDC powers the INTERLOCK and EXT_KEY_IN opto-isolators, the optional Ethernet module J9,
and an off-board radio/RF modem via terminal block TB2-9.