SAE EIA-484A-2015
Electrical and Mechanical Interface Characteristics and Line Control Protocol Using Communication Control Characters for Serial Data Link Between a Direct Numerical Control System and Numerical Control Equipment Employing Asynchronous Full Duplex Transmis

Standard No.

SAE EIA-484A-2015

Release Date

2015

Published By

SAE - SAE International

Latest

SAE EIA-484A-2015

Scope

"This standard specifies services whose architecture can be described In the context of the physical layer architecture (1) and the data link layer architecture (2) of the ISO Open Systems Interconnection Basic Reference Model- ISO 7498. This standard specifies the electrical characteristics of the interface. the mechanical characteristics and pin assignment of the connectors. the signal names@ the line control protocol using communication control characters@ and the means for error recovery for a bit serial digital data link employing asynchronous full duplex transmission. This standard does not address the user level language or protocol (reference EIA-511) except for the requirement that It shall be transparent to the user level information. The definitions of terms used in this standard are in accordance with EIA Automation Bulletin SC ""Glossary of terms for Numencally Controlled Machines'. Additional terms are defined In Annex C. The electrical characteristics of the interface are in accordance with EIA-422-A 'Electrical Characteristics of Balanced Voltage Digital Circulte. EIA-232-C or EIA-423 may be optionally used to Interface MODEMS. The mechanical characteristics of the interface are defined as a subset of EIA-449 ""General Purpose 37-Position and 9-Position Interface for Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange'. The line control protocol is based on ANSI Standard X3.28.1976 ""American National Standard Procedures for the use of the Communication Control Characters of American National Standard Code for Information Interchange In Specified Data Communication Linke. A method Is defined in this standard to permit transmission of binary data The specific protocol in this standard is a composite protocol based on subcategories DI and Fl as defined in ANSI X3.28-1976. The protocol description In terms of ANSI X3.28 is: ""Two Way Simultaneous Operation@ Message Independent Blocking. Cyclic Checking. Alternating Aclmowledgements. and Transparent Heading and Text"". NOTE: ASCII-ANSI X3.4-1977 The Line protocol specified in this standard addresses the following: ? Establish and terminate transmission ? Transfer of messages between stations ? Aclmowledgement of messages ? Order of bits ? Error detection and recovery Transmission Characteristics Transmissions shall occur asynchronously serial-by-bit and serial-by-character. The character structure for asynchronous data communication shall consist of ten signal elements having equal time intervals: one ""0 (spacing) start element. eight data btts. and one ""1"" Imarldng) stop element. Data Transmission is in accordance with American National Standard Code for Information Interchange in Serial-by-Bit Data transmission. ANSI X3.15-1976 which specifies the least significant bit shall be transmitted first. Purpose This standard is Intended to serve as a guide in the coordination of design and Implementation of digital data communication links between Direct Numerical Control (DNC) Systems and Numerical Control Units in the machine shop and the automated factory. It Is intended to meet the present and future needs of such links requiring: ? Two way simultaneous message transfer ? Error Protection ? Noise rejection ? Transparency to the data ? Independence from higher level protocols ? Point to point communications ? Switched or non-switched links1 ? Transmission via Modems An additional facet of the purpose Is to establish standards to permit DNC systems and Computer Numerical Control units of the same or different vendor source and having a common messaging syntax and protocol. EIA-511 Is such a standard. The intended communications may include but are not limited to: ? EIA-274 Format Machine Programs ? ISO 6582 ESSI Format Machine Programs ? EIA-494 Binary CC. IBCLI Exchange Data ? BINARY Data including CNC executives and diagnostic programs ? EIA-358 Code (""ASCU"" NC subset) ? GRAPHICS Data ? EIA-511 Manufacturing Messaging Syntax and Protocol 1NOTE: ""Switched links"" may require an E1A-232?C or EIA-423-A Interface until EIA?422?A Is generally implemented."

SAE EIA-484A-2015 history

• 2015 SAE EIA-484A-2015 Electrical and Mechanical Interface Characteristics and Line Control Protocol Using Communication Control Characters for Serial Data Link Between a Direct Numerical Control System and Numerical Control Equipment Employing Asynchronous Full Duplex Transmis