CAN Glossary
Control Area Networking

Dave Funk, Consultant, PHYTEC America – 06/17/1999

Terms - Alphabetized

Acknowledge
A single bit, transmitted by the receiving node, in response to data
Active Error Detection
Detected errors are made public.
Arbitration
Priority bitwise "Bid for Buss" to avoid collision
Basic-CAN
Basic functions limitations - low baud rates
Bit-Construction
Data bits, constructed of 8-12 Time Quantum's ("TQ")
Bit-Monitoring
All nodes monitor the dominate and recessive states
Bit-Stuffing
After 5 consecutive identical data bits, an alternate bit is imposed
Bus Speeds
Class A-up to 10Kb, B-10Kb to 125Kb, C-125Kb to 1 Mb
CAN
Controller Area Network
  • A multi-master bus, using open linear structure, with one logic bus line and equal nodes
  • (Complies with the 7-layer ISO/OSI communication reference model)
CAN_H
CAN High (+3.5V)
CAN_L
CAN Low (+1.5V)
CAN_Open
CAL Based Profile-Layer-Protocol by CiA for interchangeability
Can Overload-Frame
Generated by a node that is not ready
CAN Protocol Versions
V2.0A (Standard) and V2.0B Active and Passive (Extended)
CiA
CAN in Automation
CRC
Cyclic Redundancy Check (X15+X14+X10+X8+X7+X4+X3
DBT
Distributor
DCF
Device Description File
Delimiter
A passive bit between Fields
De-Stuffing
The action of the receiver to remove stuffing bits from the data stream.
Device Limitation
Maximum number of "Nodes"
Distance Limitation
130 ft (40 meters)
DLC
Data Length Code
DLL
Data Link Layer (not Dynamic Link Library)
DOD
Device Object Directory
Dominant Level (Bit)
+1.5V ( bus state for a single-line) [ "Wired-And" Pull-Down]
Dominant Bit ( Bus State)
When the CAN_H line and the CAN_L lines are both at +2.5V
EDS
Electronic Data Sheet
EMI
Electro-Magnetic-Interference
Error Active State
Node will transmit a public dominantError Frame
Error Frame
A series of consecutive dominant or recessive bits, followed by a series of 6 recessive bits.
Error Off State
Error Passive State
Node will transmit a recessive Error Frame
Full-CAN
Greater hardware management – higher baud rates
Hamming
The process of shifting & combining bits to create a unique code
Hard Synchronization
Synchronization on the falling edge of the Start Of Frame Bit
ISO
International Standardization Organization
Line-Termination
120 ohms (each end of the line)
LLC
Logic Link Control
MAC
Medium Access Control
MDTP
Multiplexed Domain Transfer Protocol
NMT
Network Management
Node
Passive or Active Device
Node Guarding
Device Failure Detection ("disconnected")
NRZ Bit Coding
Non-Return to Zero
OSI
Organization of Standards Institute (7 Layer)
Passive Error Detection
PDO
Process Data Object
Phase Buffer Segment 1
Compensation for phasing errors, by lengthening the data-bit for re-sync
Phase Buffer Segment 2
Compensation for phasing errors, by shortening the data-bit for re-sync
Propagation Segment
A programmable 1-8 Time Quanta variation (delay compensation).
Protocol
Established method or procedure for data communication.
Recessive Level (Bit)
+3.5V ( bus state for a single-line, with ground reference)
Recessive Bit ( Bus State)
When the CAN_H line is at +3.5V, and the CAN_L is at +1.5V
Re-synchronizing (Hard)
At each Recessive to Dominant edge transition
Resynchronization Jump Width
Limited to 1-4 TQ, but not longer than Phase Buffer Seg 2
RTR
Remote Transmission Request bit
SAE
Society of Automotive Engineers
SDO
Service Data Object (provide access to entries in a Device Object Directory)
SEP
Stored Event Protocol
SDO
Service Data Object
SLIO
Serial Link I/O (CAN slaves)
SOF
Start of Frame
Sync Sync
Pulse, or Synchronization Process
Synchronization Segment
The first segment within a CAN bit
TQ
Time Quantum /8 to /25 per Bit , [4 Segments per bit time]
Transfer Rates
1 Mb/sec
VAN
Vehicle Area Network

Usage Terms (by groups)

Phases

Key Phrases

Equipment Variations

Frame Formats

Fields within the Data Frame

Fields within the Remote Frame

Start of Frame

Fields within the Error Frame

Fields within the Overload Frame

Fields within the Interframe Space