ARINC SPECIFICATION 720-1-1980 (1993) PDF

Full title and description

ARINC SPECIFICATION 720-1-1980 (1993) — Digital Frequency/Function Selection (DFS) for Airborne Electronic Equipment. This characteristic defines recommended industry standards for a digital frequency/function selection system used to select radio frequencies and functions in airborne electronic equipment, including both centralized and federated DFS architectures and the associated radio-interface requirements.

Abstract

This specification describes the functional and interface requirements for Digital Frequency/Function Selection (DFS) systems for aircraft avionics. It covers system architectures (centralized and federated), electrical and logical interfaces to radio equipment, message and control formats, and verification/test considerations to ensure interoperable selection of frequencies and functions across airborne electronics. The standard also references compatibility with ARINC 429 data links where applicable.

General information

• Status: Current (issued as ARINC characteristic; listed as active in distribution catalogs).
• Publication date: Original issue: 1 July 1980; document commonly cited with a 1993 reissue/reaffirmation notation.
• Publisher: Aeronautical Radio, Incorporated (ARINC) / Airlines Electronic Engineering Committee (AEEC) characteristic (published/distributed via industry standards repositories).
• ICS / categories: Aerospace electrical equipment and on-board instruments — ISO ICS 49.060 and 49.090 (aircraft avionics / on‑board telecommunications & instruments).
• Edition / version: ARINC 720-1, original 1980 characteristic; referenced in some sources with “(1993)” indicating a reissue or catalog entry date.
• Number of pages: 22 pages (typical printed characteristic length).

Scope

This characteristic applies to the functional, electrical and logical interface requirements for digital frequency/function selection systems used in airborne electronic equipment. It defines interface signals, message formats, architectural options (centralized vs. federated DFS), and minimum performance/accuracy and test requirements necessary to ensure interoperable control of radio and other frequency‑selecting avionics equipment. The scope includes reference guidance for integration with prevailing ARINC data links (for example ARINC 429) and installation considerations within transport-category aircraft.

Key topics and requirements

• DFS system architectures: centralized controller and federated (distributed) implementations.
• Electrical and logical interface definitions between DFS controllers and radio/avionics units.
• Message formats, control words, and status reporting conventions for frequency and function selection.
• Compatibility and mapping guidance for ARINC 429 data link integration where applicable.
• Performance, accuracy, timing and reliability requirements for selection commands and acknowledgements.
• Mechanical, installation and connector considerations to support field interchangeability.
• Verification and test procedures, including bench and system-level checks to validate DFS operation.

Typical use and users

Used by avionics equipment manufacturers, aircraft systems integrators, airline engineering groups, certification authorities and avionics test laboratories to design, integrate and verify frequency/function selection interfaces between flightdeck control units and airborne radios or other frequency‑selecting equipment. Systems engineers and maintenance planners also reference the characteristic when ensuring interoperability and maintainability of DFS installations.

Related standards

Primary related standards and guidance include ARINC 429 (data‑bus format and signalling used for many avionics point‑to‑point links), general ARINC characteristic series for avionics interfaces, and industry avionics environmental and software standards (for example DO‑160 environmental testing and RTCA/DO‑178 guidance for software where DFS functions are software‑controlled). ARINC 720-1 is part of the broader family of ARINC characteristics that define avionics interface standards.

Keywords

Digital Frequency Selection, DFS, ARINC 720-1, avionics interface, radio interface, ARINC 429, AEEC, airborne electronic equipment, frequency/function selection.

FAQ

Q: What is this standard?

A: ARINC 720-1 is an ARINC characteristic titled “Digital Frequency/Function Selection (DFS) for Airborne Electronic Equipment” that specifies functional and interface requirements to enable digital selection of radio frequencies and related functions in aircraft avionics.

Q: What does it cover?

A: It covers DFS system architectures (centralized and federated), electrical and logical interfaces to radios and avionics units, message/control formats, performance and reliability requirements, and test/verification guidance; it also provides mapping guidance for integration with ARINC 429 links.

Q: Who typically uses it?

A: Avionics manufacturers, aircraft systems integrators, airline engineering departments, test labs and certification authorities use this characteristic when designing, integrating and validating DFS-capable equipment and installations.

Q: Is it current or superseded?

A: The characteristic is listed in industry catalogs as the ARINC 720-1 characteristic originally issued in 1980; references show a 1993 reissue notation in some catalogs. Users should check their organization's ARINC/AEEC distribution or standards repository for the latest status and any amendments before design or certification activities.

Q: Is it part of a series?

A: Yes — ARINC 720-1 is one characteristic in the ARINC (AEEC) family of avionics interface standards; related ARINC characteristics and reports cover complementary interfaces, data buses and installation practices.

Q: What are the key keywords?

A: DFS, digital frequency/function selection, ARINC 720-1, avionics interface, radio interface, ARINC 429, AEEC.