CAN dictionary

Explains vocabulary and abbreviations used in CAN technology

Alphabetic selection:


fault confinement

CAN nodes are able to distinguish short disturbances from permanent failures. Defective transmitting nodes are switched off, meaning the node is logically disconnected from the network (bus-off).

fault confinement entity (FCE)

A supervisor entity fulfilling the fault confinement.

fault-tolerant transceiver

Transceivers as specified in ISO 11898- 3 and ISO 11992-1 are capable of communication via one bus-line and CAN ground when one bus-line is broken down, short circuited or termination resistors are not well connected.


See FD base frame format.


See fault confinement entity.

FD base frame format (FBFF)

In CAN FD, the FBFF uses 11-bit identifiers in data frames.

FD enabled

CAN device able to receive and transmit FD frames and Classical frames.

FD extended frame format (FEFF)

In CAN FD, the FEFF uses 29-bit identifiers in data frames.

FD format indicator (FDF)

This bit distinguishes between Classical CAN frames (dominant) and CAN FD frames (recessive). In frames with 11-bit identifiers, FDF comes after the IDE bit. In frames with 29-bit identifiers, it comes as the first bit of the control field.

FD frame

Data frame using FBFF or FEFF format.

FD intolerant

A CAN device that is only able to receive or to transmit Classical frames; FD frames are destroyed.

FD tolerant

A CAN device that is not able to transmit or to receive FD frames. However, it does not destroy the CAN FD frame by an error frame.


See FD format indicator.


See FD extended frame format.

field device

Independent physical entity of an automation system which hosts zero, one or several CAN open devices, and performs specific functions such as e.g. controlling, actuating, sensing and/or data transferring.

finite state automaton (FSA)

FSA is an abstraction to describe the behavior of a black box. It is composed of several states, transitions between those states, and actions.

flying master

In safety-critical applications, it may be required that a missing NMT master is substituted automatically by another stand-by NMT master. This concept of redundancy is called flying master.

form error

A corruption of one of the pre-defined recessive bits (CRC delimiter, ACK delimiter and EOF) is regarded as a form error condition that will cause the transmission of an error frame in the very next bit time.


Data link protocol entity specifying the arrangement and meaning of bits or bit fields in the sequence of transfer.

frame coding

Sequence of fields in the CAN frames, e.g. SOF, arbitration field, control field, data field, CRC field, ACK field and EOF for data frames. The frame coding covers also the bit stuffing.

frame format

The CAN standard distinguishes between the base frame format (CBFF and FBFF) using 11-bit identifiers and the extended frame format (CEFF and FEFF) using 29-bit identifiers.

frame padding

Frame padding is padding of a CAN data field to an 8-byte data.

frame types

In CAN, four frame types are used: data frame, remote frame (only in Classical CAN), error frame, and overload frame.


See finite state automaton.

full CAN

A term used in the early days of CAN describing an implementation, which features single receive and transmit buffers for a number of IDs.

function code

First four bits of the CAN identifier in the CANopen and CANopen FD pre-defined connection set indicating the function (e.g. SDO or USDO request, TPDO or EMCY).

FUP message

CAN data frame containing the remainĀ­ ing part of the current value of a timeĀ­ base plus the value of transmit delays of the preceding SYNC message. It is defined in CiA 603 (in development).

Source CANdictionary (2016) - CiA CAN in Automation -