Glossary - neoVI
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ALDL - Assembly Line Data Link - The pre-OBD-II communications link found on GM vehicles.

Arbitration ID (Arb ID) - The identifier portion of the CAN (Controller Area Network) message.

CARB - California Air Resources Board - Agency in California which sets emission standards which relate to OBD.

CAN - Controller Area Network - A vehicle network which has messages which contain an Arbitration ID (Arb ID) field, a DLC data length code field and an eight byte data field. The Arb ID can be 11 bits or 29 bits. This specification was released by Bosch.

Class 2 - General Motors messaging strategy based on the VPW part of the J1850 specification.

Ford SCP - Ford Motor Company messaging strategy based on the PWM part of the J1850 specification

GMLAN - General Motors messaging strategy using CAN. This strategy is planned to replace the Class 2 messaging strategy (J1850).

IDB - Infotainment data bus - Different specifications related to in-vehicle information and entertainment data buses. IDB-C is a specification that uses dual wire CAN.

ISO9141 - A UART based protocol which is allowed under OBD-II.

J1587 - Standard which defines messaging packets for J1708 physical layer networks.

J1708 - Physical Layer specification and Protocol for using a RS485 style network. Used in truck and bus applications.

J1850 - Physical Layer and Protocol specification for north American in-vehicle communications. It consists of two physical layers VPW and PWM which share similar data formats. This includes a 11 byte message with a CRC. In-frame responses are also available in the protocol.

J1939 - Specification for communications for Heavy Truck and Bus based on CAN messages using a 29 bit Arb ID.

J1962 - Specification detailing the diagnostic connector found in North American vehicles. This connector is also called the ODB-II connector and the ALDL connector.

J1979 - Specifications which detail ODB-II test modes and data. This includes requesting values from the Vehicle such as RPM, Engine Load, Coolant Temp, Vehicle Speed, Etc.

Keyword 2000 - An enhanced version of ISO9141 which specifies many diagnostics services.

LIN - Local Interconnect Network - A UART based network which consist of a master and many slave nodes.

Messaging Strategy - This is a higher-level protocol which defines how the content of vehicle network messages is used and when messages are transmitted.

OBD - On-board Diagnostics - Software inside the Vehicle which automatically diagnoses the Vehicle. OBD-II specifies diagnostics services required by law in North America. 

Physical Layer - The electrical signaling portion of a protocol.

PWM - Pulse Width Modulation - This type of electrical coding is used in the J1850 spec PWM protocol.

RS232 - PC communication port which can operate at speeds between 300 and 115k bits per second.

SAE - Society of Automotive Engineers (www.sae.org)

UART - Universal Asynchronous Receiver Transmitter - A network protocol based on a UART found on many microcontrollers.

USB - Universal Serial Bus - A 12 megabits per second bus communication port.

VPW - Variable Pulse Width - This type of electrical coding is used in the J1850 spec VPW protocol.

Last Update: Wednesday, April 11, 2001