United States Department of Transportation logo AASHTO logo ITE logo NEMA logo

NTCIP 1201 - Global Object Definitions


NTCIP 1201 V3 has been in preparation for several years. Version 3.03 is available for download as a User Comment Draft at NTCIP.ORG. Version 3.08 was approved as a Recommeded Standard in April 2008.

This Fact Sheet was written on September 25, 2009. The status of the standard at the time was: Published in October 2005.

This Fact Sheet was last verified on October 09, 2009

Overview

The National Transportation Communications for Intelligent Transportation System (ITS) Protocol (NTCIP) is a family of standards that provides both the rules for communicating (called protocols) and the vocabulary (called objects) necessary to allow electronic roadside equipment from different manufacturers to operate with each other as a system. The NTCIP is the first set of standards for the transportation industry that allows transportation systems to be built using a "mix and match" approach with equipment from different manufacturers. Therefore, NTCIP standards reduce the need for reliance on specific equipment vendors and customized one-of-a-kind software. To assure both manufacturer and user community support, NTCIP is a joint product of the National Electronics Manufacturers Association (NEMA), the American Association of State Highway and Transportation Officials (AASHTO), and the Institute of Transportation Engineers (ITE). More information concerning the NTCIP family of standards and their related documents is available in the NTCIP 9001 - NTCIP Guide, available on-line at (www.ntcip.org).

Human communications relies on a vocabulary of words, each defined with a fixed meaning and spelling that are understood by the members of the conversation group. Computers have a similar vocabulary, called "objects" in the NTCIP standards. These objects define all possible commands, responses and information that may be exchanged among microprocessor-controlled electronic equipment, a central computer, and by extension, their human operators. The NTCIP groups these objects by subject material (e.g., dynamic message signs) and calls these groupings "object definitions." The objects defined in this standard are generic to many different types of devices, e.g., the standard includes objects for time and manufacturer's name.

What are these standards for?

This standard, NTCIP 1201 - Global Object Definitions, provides the vocabulary - commands, responses and information - necessary for general device management, including those objects required for device identification, time-based schedule configuration, and event log configuration. As a minimum, all field devices that are required to communicate with a central system should support the device identification objects.

The NTCIP-Global Object Definitions defines the vocabulary for those features that are supported by a variety of devices. Simple devices may only support the device identification objects. More complex devices, such as controllers, may be required to support additional features such as time base schedules and event logs. The conformance requirements previously included in version 1 have been removed from this standard. This document only defines the data that may be useful for a given device; any requirements for supporting a specific piece of data is defined in device-specific standards, such as NTCIP 1202 for Actuated Traffic Signal Controller (ASC) Units.

Who uses them?

This standard, NTCIP 1201 - Global Object Definitions, should be used by transportation engineers involved with the specification, testing, and operation of field equipment. Hardware and software developers should design their products to be compliant with this standard, including support of any appropriate options.

How are they used?

This standard, NTCIP 1201 - Global Object Definitions, defines a vocabulary of "objects" used to assure that the transportation management center computer-system and roadside devices "speak" a common language. A message must be understood by the device it was intended for, and equally important, it must not be misunderstood or misinterpreted by another device on the same network. Object definitions unambiguously define the content, terminology, value, and format of commands, responses, and information affecting communications with field devices.

This standard must be used with one of the NTCIP communications profiles (NTCIP 2101, 2102, etc.) which provide the communications channel for information transfer between devices.

Scope

Communications between a transportation management center’s central computer and field devices are accomplished by using the objects defined in NTCIP 1201 - Global Object Definitions. These objects define the information, commands and responses that must be understood by the devices at both ends of the communications channel.

Related documents

The following ITS standards and documents are related and should be considered when using this standard:

The following standards and documents, while not part of the ITS standards, should also be considered when using this standard:

How to obtain Standards
American Association of State Highway and Transportation Officials
202-624-5800
https://www.transportation.org/
Institute of Transportation Engineers
202-289-0222
http://www.ite.org
Association of Electrical and Medical Imaging Equipment Manufacturers (NEMA), formerly known as National Electrical Manufacturers Association
703-841-3200
http://www.nema.org