CAN dictionary

Explains vocabulary and abbreviations used in CAN technology

Alphabetic selection:



See medium access control.


Communication or application entity that is allowed to control a specific function. In networks this is for example the initialization of a communication service.

master-slave communication

In a master/slave communication system the master initiates and controls the communication. The slave is not allowed to initiate any communication at all.

matrix cycle

In TTCAN (ISO 11898-4) the matrix cycle is made up of one or more basic cycles. Each basic cycle starts with the reference message but may be followed by different windows.


See medium attachment unit.


See medium dependent interface.

medium access control (MAC)

The MAC sub-layer represents the lower part of the OSI data link layer. It services the interface to the LLC sub-layer and the physical layer, and comprises the functions and rules that are related to data en-/de-capsulation, error detection and signaling.

medium attachment unit (MAU)

Unit (functional part of CAN physical layer) used to couple a node to the transmission medium. It comprises the physical medium attachment (PMA) and the medium dependent interface (MDI).

medium dependent interface (MDI)

The MDI defines the interface that ensures proper signal transfer between the media and the physical medium attachment. It defines the connector, cable and termination resistor requirements.

message buffer

CAN controller chips implement message buffers for frames to be received and/or to be transmitted. The implementation and the use of message buffers are not standardized.

message doubling

See double reception of message.


These CAN-based higher-layer protocols have been defined by a group of interested companies and government bodies associated with the specification, manufacture and test of military vehicles. MilCAN A is based on J1939, and MilCAN B is based on CANopen.

minimum time quantum

Smallest time quantum configurable for a specific implementation.


See multiplex PDO.

multicast transmission

Addressing, where a single frame is addressed to a group of nodes simultaneously.

multi-master communication

In a multi-master communication system every node may temporarily control the bus communication. This means every node has theoretically the right to access the bus at any time when the bus is in idle state.


Communication entity comprising several C-PDUs as defined in CiA 602-2.

multiplex PDO (MPDO)

The MPDO is made of 8 byte including one control byte, three multiplexer bytes (containing the 24-bit index and sub­ index), and four bytes of object data.

Source CANdictionary (2016) - CiA CAN in Automation -