User's Manual

Model 1150A DVOR
2-38 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.
The U37 buffer reads TACAN antenna controller signals which enter through connector P1 and are converted to
TTL by U34. The U38 output latch directs activity of the TACAN antenna controller after the U38 latch signals are
converted to RS422 by U35 and U36. The U38-19 loop-back signal may be used for fault-isolation purposes to
buffer U37-9. Latch U38-16 also controls ~TACAN_RESET though transistor Q5 and TVS diode CR42 before
routing to P1-C8.
2.3.2.11
Interface CCA Theory
The Interface CCA provides interface connections between the RMS/Facilities/Control Backplane CCAs and the
outside world. Examples include spare analog and digital inputs, spare digital outputs, temperature sensors, smoke
detector, intrusion sensor, and a TACAN antenna controller. RS232 communications are provided to RCSU and
PMDT terminals as well as an optional Ethernet module. All signals are protected by transient voltage suppression
(TVS) devices on the Interface CCA before exiting.
2.3.2.12
Interface CCA Block Diagram Theory
NOTE
TACAN interfaces are described but not used in the VOR system. The Interface CCA is also
used in DME/TACAN systems.
Refer to Figure 2-14. All connections between the Interface CCA and the RMS/Facilities/Control Backplane CCAs
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.
Connectors J5 and J6 are DB9-types which provide interface to the RCSU and PMDT terminals mentioned
previously.
Connector J7 is an RJ11 phone jack provided for exterior temperature sensing.
Connector J8 is a header provided for in-factory test purposes.
Connector J9 is an RJ45 jack intended for use as an Ethernet port. The port will be powered by a +3.3V DC-DC
converter (PS1).
Terminal block TB1 facilitates connection of up to ten spare analog inputs, four digital inputs, and four digital
outputs.
Terminal block TB2 allows connection of the RCSU and Dial-Up modem tip and ring signals. These signals are
transient protected by common-mode chokes as well as spark-gaps, sidactors, and power resistors. INTERLOCK
and EXT_KEY_IN signals are TVS-protected and optically isolated. True isolation for these signals may be enabled
or disabled depending on the strapping of JP1 and JP2. EXT_KEY_OUT signals are optically isolated and TVS-
protected before exiting via TB2.
SMOKE_DETECTOR, INTRUSION_SENSOR, ILS-VOR_RX_232, and ILS-VOR_TX_232 signals are TVS-
protected before further routing. DET_IDENT1 and DET_IDENT2 signals are scaled as well as TVS-protected
before exiting via TB2.
Earth ground lug E1 provides a return path for all transient voltage protection devices on the Interface CCA.