ISA50.3, Data Link Subcommittee

Scope

To develop standards for signals used in process measurement and control, to transmit information between subsystems or separated elements of systems. Such signals may be analog or digital. However, data highway and other time-shared transmission paths, such as those within the scope of ISA72, are excluded.

Purpose

To define a common interface between components of electronic measurements and/or control systems.

A Word from the Chairman

Richard Caro, Chairman of ISA50 since 1993, and Cullen Langford, Chairman from 1987 to 1993, wish to thank everyone who participated in the development of the ISA-50.02 Fieldbus standards. The standards were administratively withdrawn as ANSI standards and have now also been withdrawn as ISA standards as they are no longer in use due to the issuance and acceptance of a more current IEC 61158 standards series.

The technical report ISA-TR50.02, Parts 3 & 4, Fieldbus Standard for Use in Industrial Control Systems, Parts 3 & 4, TR1: Technical Report for Fieldbus Data Link Layer - Tutorial, under the coordination of Patrizio Leviti, is still in use. This tutorial explains the "why" and "how" relevant to "what" has been included in the Data Link Layer standards. This document addresses those who have not had any contact with the Data Link Layer Standards, now a part of the IEC 61158 standards series.

The tutorial eases the initial review of the Data Link Layer Standards by 1) presenting the particular reasons why some of the features have been included; 2) describing its main features; and 3) making simple examples or graphic representations of these features. The tutorial goes into further detail by 1) linking separate parts of the standards relevant either to the same subject or to related items; and 2) making detailed examples of this Data Link Layer mechanism.

Ashok Gupta
ISA50.3 Chair

Paul Andreassen Information Member FieldNet AS Phone: 479 303 0193 Fax: 476 682 1371	Eliana Brazda Staff Contact ISA Phone: (919) 990-9228 Fax: (919) 549-8288
Antony Capel Information Member Comgate Engineering Ltd Phone: (613) 235-4778 Fax: (613) 248-4644	Salvatore Cavalieri Voting Member Universita' degli studi di Catania Phone: +39 095 738 2362 Fax: +39 095 338280
Robert Crowder Voting Member	Bernard Dumortier Voting Member Schneider Electric Phone: +33 9 82 50 99 60 Fax: +33 1 39 16 38 84
Ashok Gupta Voting Member Chair Aniotek Inc Phone: (732) 274-2648 Fax: (732) 274-2332	David Hewitson Voting Member Ronan Engineering Co Phone: (818) 888-3521 Fax: (818) 992-6435
Toru Ito Voting Member Fuji Electric Phone: 81425 84430 Fax: 81425 810400	Vincent Jacobson Voting Member
Jean-paul Lerare Voting Member CEGELEC Phone: 33146 29159 Fax: 33146 327523	Patrizio Leviti Voting Member Alstom Power Italia SpA Phone: +39 02 26232 783 Fax: +39 02 26232 293
Klaus-Peter Lindner Information Member Endress+Hauser Process Solutions AG Phone: +41 79 335 66 38 Fax: +41 61 715 2802	Orazio Mirabella Information Member Univ di Catania Phone: (399) 573-2361 Fax: (399) 533-8280
Lutz Oreans Voting Member Siemens AG Phone: +49-7 21-595-4858 Fax: +49-7 21-595-2181	Tom Phinney Voting Member Phone: (602) 938-3163
Rajkumar Rajendran Information Member Shell Phone: +74242663177	Kang Shin Information Member Univ of Michigan Phone: (313) 947-0609 Fax: (313) 947-0941
Libanio Souza Voting Member Smar Intl Corp Phone: +55 16 6456455 Fax: +55 16 645 6450	Ian Verhappen Information Member Industrial Automation Networks Inc Phone: (403) 829-1077
Robert Webb Voting Member ICS Secure LLC Phone: (360) 394-3692 Fax: (360) 930-0546	Graeme Wood Voting Member Graeme Wood Consulting Phone: +44 1 883 62 7797 Fax: +44 1 870 135 1131
Qi YAN Information Member Emerson Phone: 13918009479