MotoHawk SAEJ1939 PGN Transmit Raw

This block sets up a raw PGN Transmit message using the specified handler.

Block ID

Library

MotoHawk_Protocols_lib

Description

The "PGN Definition" script is required to follow the template outlined in the "motohawk_saej1939_pgntx_raw_example" example file.

The definition script specifies a constant value, a port value, or an external datastore for each input parameter. The location of the block in the application will determine when the port-related information is updated.

If interval is specified as "0", then the block will not transmit unless the PGN is requested via PGN 59904. At this point, there is no "transmit now" function. The PGN can only be transmitted based on the interval and on request.

The PGN transmit block is capable of referencing J1939 SPN and Vector SPN transmit blocks by name in order to import the referenced SPN's data into the Raw PGN transmit data. The referenced SPN will overwrite any constant, port or data store defined PGN block data. With an SPN reference, an SPN offset may be provided in the PGN's data definition script to offset the SPN into the correct start bit location of the PGN. It is the application developers responsbility to verify that multiple SPN references don't write to the same bits in a PGN.

The block will enforce some PGN numbering rules specified in J1939-21. It is required that the application developer become familiar with these rules.

A brief overview:

PDU Format 1 means that Destination Address is available for use. PDU2 PGNs do not have this available.
Some PGN ranges do not allow multipacket transmissions and thus the "maximum length" parameter must be set to a number that is less than or equal to 8.

The interval requirements are not enforced by the block. The user is responsible for assigning appropriate intervals.

Block Parameters

Parameter Field	Values	Comments/Description
PGN Definition	String	Evaluates to a PGN Transmit Raw definition specified in the example script.