Table Of Contents

Applying J1939 Application Protocol

Last Modified: January 1, 2018

Apply J1939 Application protocol to signals to .

  1. Click Add Signals on the CAN port you want to configure.
  2. Select the Database that contains the signals you want to update.
  3. Select the Cluster that contains the signals you want to apply J1939 to.
  4. Select J1939 from the Application protocol pull-down menu.
  5. Select the desired signals from the Signals pane.
    spd-note-note
    Note  

    The Signals pane is organized by frames, and each frame contains a grouping of signals. The Signals Search filter searches for signal names only. To locate a specific frame within the database, search for a signal contained by the frame, select the signal, and then clear the search results.

  6. Click Okay.

J1939 application protocol uses a 29-bit extended frame identifier. The ID is divided into several parts, including the PGN, which identifies the frame and defines which signals it contains.

You can send a frame to a global address (all nodes) or a specific address (node with this address). This information is coded inside the PGN, as shown in the following figure.

The PF value in the identifier defines whether the message has a global or specific destination:

  • 0-239 (0x00-0xEF): specific destination
  • 240-255 (0xF0-0xFF): global destination

In the CAN identifier, this looks like the following (X = don't care):

  • 0xXXF0XXXX to 0xXXFFXXXX are messages with global destination (broadcast)
  • 0xXX00XXXX to 0xXXEFXXXX are messages with specific destination

For global messages, the PS byte of the ID defines group extension. This extends the number of possible global PGNs to 4096 (0xF000 to 0xFFFF).

For destination-specific messages, PS defines the destination address, so PF defines only 240 destination-specific PGNs (0-239).


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