Purpose: This document contains the electrical interface definition, and a functional description of a portable maintenance access terminal (PMAT). The intent of this document is to provide general and specific design guidance for the development of a PMAT primarily for airline use. This document describes the aircraft interface, operational capabilities, and the standards necessary to achieve interoperability with ARINC 624 Onboard Maintenance Systems (OMS) and ARINC 649 Electronic Library Systems (ELS).

This characteristic defines the interface protocol, and the basic and optional PMAT functions. The PMAT should be designed to operate in an ATN-compliant environment.