User's Manual Part 2
T
2
CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
Use or disclosure of information on this page is subject to the restrictions in the proprietary notice of this document.
4--49
TAWS/RWS PINOUTS AND PIN DEFINITIONS
3. TAWS/RWS Specifications
The Ground Collision Avoidance Module (GCAM) function performs the core TAWS and
reactive windshear detection processing. Inputs to the GCAM are aircraft state variables,
aircraft performance models, the combined terrain and airport database, aircraft discretes, and
ARINC label busses. The outputs from the GCAM are the TAWS alerts, reactive windshear
(RWS) alerts, and the terrain display buffers.
The TAWS/RWS input data is attained from a variety of aircraft LRUs depending on the
configuration of the specific aircraft. Since the source of the TAWS/RWS input data is
primarily unknown until a Customer Worksheet (Appendix A) and aircraft survey has been
completed, most of the ARINC 600 connector pins are configurable. Once the origin of the
TAWS/RWS input data has been determined an Aircraft Specific Data Base (ASDB) is
generated by ACSS that defines the pin assignments for that specific aircraft. At installation
time, the ASDB is loaded into the aircraft’s Aircraft Personality Module (APM) which then
remains with the aircraft throughout any T
2
CAS LRU removal/replacements to retain the
aircraft configuration data.
In addition to the configurable pins, the TAWS/RWS also contains some permanent or
non-- configurable pin assignments as well as some pin assignments that are shared with the
TCAS functionality.
This section is organized in a generic format to accommodate the dynamic, aircraft dependant
pin assignments. The flow for configurable pin assignments is as follows:
• An aircraft configuration type is determined based on the equipment installed.
• Using the aircraft configuration data, the pin assignments are engineered, assigned and
documented in the ASDB system requirements.
• An Aircraft Configuration Table is then generated in Appendix B of this document that
details the specifics of the equipment installed on the new aircraft (columns) and assigns
an Aircraft Installation Number to the newly identified aircraft installation type (rows).
• The Aircraft Installation Number then references a Table that assigns the TAWS/RWS
signals to an Analog, Discrete or Digital Input/Output number. For example, FMS #1 (Left)
could be assigned Digital Input #2. Table 4--13 of this section would then be referenced to
obtain the specifics (pin numbers, usage, tolerances, etc.) of Digital Input #2.
• If any new aircraft installation data and pinouts match a previously identified aircraft
installation type, then that specific aircraft (identified at a minimum by Customer and aircraft
type) is added to the existing Aircraft Configuration Table.
In addition to providing configurable and non--configurable pinouts, this section also provides
the following:
• Characteristics and tolerances for the generic analog, discrete and digital inputs/outputs.
For example, analog Input #1 must be a 3W or 2W Synchro, be within the
voltage/impedance tolerances defined in Table 4-- 10 and Table 4--11, and have the signal
characteristics defined in the applicable subsection of the “Programmable Analog Input
Pins” section.