CAN dictionary

Explains vocabulary and abbreviations used in CAN technology

Alphabetic selection:



In general, the term refers to a CAN message identifier. See CAN identifier.

identifier extension flag (IDE)

This bit distinguishes whether the frame uses the base frame format (dominant) or the extended frame format (recessive). Thus, the IDE bit indicates if the following bits are interpreted as control bits or the second part of the 29-bit identifier.

identifier field

The identifier field contains 11 bits in base frame format, and additional 18 bits in extended frame format.


State of the network, when there is recessive state after the completion of a frame.

idle condition

Detection of a sequence of 11 consecutive sampled recessive bits on the bus.


See intermission field.


16-bit address to access information in the CANopen object dictionary; for array and records the address is extended by an 8-bit sub-index.

inhibit time

Parameter in CANopen that defines the minimal time that elapses between transmission of the same PDOs and emergency messages.

initialization state

NMT slave state in CANopen that is reached automatically after power on and communication or application reset.

inner priority inversion

Occurs, if a low-prior message can not be transmitted because of high-prior message traffic on the CAN network and a high­ prior transmission request occurs in the device and cannot be passed to the CAN controller due to the still pending low-prior transmission request.


A node is integrating into bus communication after starting the protocol operation during bus off recovery, or after detecting the protocol exception event; until the idle condition is detected.

interface profile

CANopen profile that describes just the interface and not the application behavior of a device, e.g. gateway device.

intermission field (IMF)

Three-bit field after the EOF. Detection of a dominant bit at the third IMF bit is interpreted as SOF.

I-O message

Communication object in DeviceNet trans­ porting application objects representing inputs or outputs. I/O messages are mapped to one or more CAN data frames supporting segmented transfer.

ISO 11783 series

International standard series defining the CAN-based application profile used in agriculture and forestry machines and vehicles (Isobus). It is based on the J1939 application profile.

ISO 11898-1

International standard defining the CAN data link layer including LLC, MAC and PCS sub-layers.

ISO 11898-2

International standard defining the CAN high-speed medium access unit. Since version ISO 11898-2:2016 it includes also transceivers supporting low-power mode (former ISO 11898-5) and selective wake­ up functionality (former ISO 11898-6).

ISO 11898-3

International standard defining the CAN fault-tolerant, low-speed medium access unit.

ISO 11898-4

International standard defining a time­ triggered communication protocol based on the Classical CAN data link layer protocol.

ISO 11898-5

ISO 11898-5:2007 represents an extension of ISO 11898-2:2003, dealing with functionality for systems requiring low-power consumption features while there is no active bus communication. The standard is now included in ISO 11898-2:2016.

ISO 11898-6

International standard defining selective wake-up functionality for high-speed transceiver included in ISO 11898-2:2016. Those transceivers implement partly the CAN (FD) protocol.

ISO 11992 series

International standard series defining a CAN-based application profile for truck-trailer communication. Part 2 specifies the brake and gearing devices, part 3 specifies other devices, and part 4 defines the diagnostics.

ISO 15745-2

International standard defining an application integration framework for ISO 11898 based control systems such as CAN open and DeviceNet.

ISO 16844 series

International standard defining the CAN­ based tachograph to be used in trucks and buses.

ISO 16845-1

International standard that defines the conformance test plan for ISO 11898-1 implementations.

ISO 16845-2

International standard that defines the conformance test plan for high-speed transceiver compliant with ISO 11898-2.

Source CANdictionary (2016) - CiA CAN in Automation -