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mapp Services V5.16
A PGN that is not available via the configuration can be transmitted or received using function blocks MpJ1939Receive, MpJ1939Transmit and MpJ1939SpecificRequest.
To work with PGNs that are not available via the configuration, it is recommended to take the necessary information from the J1939 standard. For additional information, see here.
The desired PGN is defined via input parameter "PGN". The numeric code of the PGN is specified. Which numerical value a PGN identifies can be taken from the J1939 standard. There are two ways to manage the information of a PGN.
Depending on how the signals are in the PGN, a decision can be made between the two variants. The signals of a PGN always have a start bit and maximum length.
It is important to note that a PGN can have limit values, scaling and an offset. These must be taken into account when further processing the PGN. The limit values, offset or scaling of a PGN can be taken from a J1939 database that can be downloaded here.
For example, if you have a PGN containing signals "Test_A" and "Test_B", these signals have a start bit and defined length.
For variant Managing a PGN using a PV, the signals must follow each other directly. There are no bits between the signals:
For variant Managing PGN in memory, the signals do not follow each other directly. In the example below, signal "Test_A" has a length of 8 bits. Signal "Test_B" only starts at bit position 16, however.