- Overview
- 1. Introduction
- 2. General Description of the Protocol
- 3. Document Structure
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4. Fundamentals
- 4.1. Names and Addresses
- Device Names
- Device Address
- 4.2. Parameter Group
- Structure and Type of a Parameter Group
- Example of a Global Parameter Group
- Example of a Specific Parameter Group
- Parameter Groups reserved specially for the Protocol
- 4.3. Data Management
- Suspect Parameter Number (SPN)
- SLOT Definition
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5. Network Management
- Network Access
- 5.1. Address Conflict
- Solution and Configurations
- Handling in a Dynamic Network
- 6. Transport Protocols (Multi-packet Messages)
- 7. Diagnostics
General
PGN
A parameter group is a set of information that has a common context and thus shares the same transmission rate. Each parameter group is identified by a unique number – the Parameter Group Number (PGN). The parameter group is easily confused with the CAN identifier. The purpose of this chapter is to explain the difference between a J1939 parameter group and a CAN message identifier. The following comparison presents the commonalities and differences:
Commonalities:
- Grouping of signals with identical or similar context
- Can be identified by a unique number
- Contains application and protocol data
Differences:
- Not limited to 8 data bytes (upper limit of 1785 bytes)
- Can be transmitted point-to-point
- The priority of the message is independent of the PGN
If a data length of more than 8 bytes is defined for a parameter group, this will be sent as a multi-packet message. The standard provides a so-called transport protocol.
Last modified: Friday, 27 April 2018, 8:23 AM