Murphy Xpansion IX3212, Справочное руководство

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Section 80 00-02-0829
2018-02-26 - 53 -
4.6 Example Messages
4.6.1 Arbitration Field
The IX3212 PDM follows SAE J1939-21, which defines proprietary Parameter Group Numbers
(PGNs). The Protocol Data Unit (PDU) is the bit arbitration field of every message on the CAN
bus.
The first three bits are the Priority (P) of the message. The recommended value is 5h (5).
When combined with the Reserved (R) bit and Data Page (DP) bit, the value becomes 14h
(20).
NOTE: Your application may require adjusting the priority based on other
devices on the CAN bus.
The PDU1 format is followed, and the PDU Format (PF) is always set to EFh (239), which is
reserved for proprietary use.
The PowerView display or CAN bus controller send messages to the PDM at Destination
Address 1Eh (30), which is the same as the PDM Source Address.
The PDM broadcasts messages to Destination Address 11h (17) regardless of the actual
Source Address of the PowerView display or CAN bus controller.
The resulting arbitration headers of the messages sent to and from the PDM would look like
the following.
The eight data bytes from the various PGNs follow the respective header.