ARINC 735B

Purpose of this Document

This document describes a Traffic Computer with Traffic Alertand Collision Avoidance System (TCAS) functionality that providesthe necessary interface definitions and protocols to accommodatethe requirements of RTCA DO-185: Minimum OperationalPerformance Standards for TCAS (latest version applies).

Additionally, this document describes interfaces and protocolsnecessary to accommodate Cockpit Display of Traffic Information(CDTI) based on reception of Automatic Dependent Surveillance –Broadcast (ADS-B) data and Traffic Information Services – Broadcast(TIS-B) data. The equipment becomes TCAS with ADS-B and TIS-Bfunctions added, as defined by RTCA DO-260: Minimum OperationalPerformance Standards for 1090 MHz (latest versionapplies)

COMMENTARY

The control and Human Machine Interface (HMI) for CDTI and ADS-BIn have not been standardized. Therefore this specificationattempts to provide interfaces which could potentially support manydifferent options for control and interfacing. It is expected thatactual aircraft installations will use a subset of these.

Older TCAS equipment (ARINC 735 and ARINC 735A compliant) isdesigned to be backward compatible with Mode S transponders definedby ARINC Characteristic 718, which are only compatible with RTCADO-185. ARINC 735A equipment is compatible with Mode S transpondersdefined by ARINC 718 and 718A, which are compatible with both RTCADO-185 and RTCA DO-185A.

ARINC 735B TCAS equipment (defined by this standard) is intendedto be compatible with ARINC 718A transponders that provide extendedsquitter capability. ARINC 718 transponders may also be used.However, this will result in the loss of ADS-B transmitcapability.

As of the release of this document, RTCA DO-185B requirementswere not yet completed, but the essential interface level changeswere considered captured. Therefore, we do not anticipate thatchanges planned for RTCA DO-185B will impact this document. Theadditional labels found in Attachment 19K and 19L are meant tocapture the latest requirements. These labels include hybridsurveillance capability indications, RTCA DO- 185B compatibility,and TCAS-to-transponder part number reporting. Any changes to RTCADO-185B that affect this document will be reflected in a futureSupplement to this document.

RTCA MOPS for ASSAP/CDTI are under development at the time ofthis writing.

Edition:

07

Published:

12/14/2007

Number of Pages:

348

File Size:

1 file , 1.6 MB