MotoHawk SAEJ1939 Dynamic PGN Transmit Raw

This block sets up a raw Dynamic 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_dyn_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.

The dynamic 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 PGN value is "dynamic" and that allows the user to change the value at run time. The PGN Transmit Raw block has a static PGN. The dynamic PGN allows for more flexibility, but also incurs a penalty of more RAM and CPU throughput than the static PGN. It is recommended to use the static PGN unless the PGN or interval needs to change at run time.

The interval value is also "dynamic" and that allows the user to change the value at run time. If the value is 0, then the PGN will only be available by PGN Request. Otherwise, the interval will be transmitted at the rate specified. Note that a change to the interval will be applied immediately and the minimum rate is governed by the SAEJ1939 handler. The transmit rate should be a multiple of 10ms.

Block Parameters

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