mapp Services V5.16
Using the mapp component, data can be transmitted and received via a CAN interface that uses the J1939 network protocol. This can be diagnostic data or control information, for example. For information about how the J1939 CAN message is structured, see here. See this link for how the network protocol J1939 is structured and works:
Data is transmitted and received using function block MpJ1939Generic.
Which information is transferred is determined by the "parameter group number" (PGN). The PGNs to be transmitted or received are defined in the MpJ1939Generic configuration. Some of the PGNs are available in the configuration. Some PGNs can be queried cyclically; others are available on request.
PGNs that are defined by the configuration
For each PGN to be used, a process variable of a certain data type must be created. This process variable contains the desired information to be transmitted or received. For more information, see Working with PGNs in the configuration.
PGNs that are not defined by the configuration
Due to the variety of possible PGNs, not all are directly available in the configuration. For those PGNs that are not found in the configuration, function blocks MpJ1939Receive, MpJ1939Transmit or MpJ1939SpecificRequest can be used.
Function blocks MpJ1939Receive and MpJ1939Transmit can be used for PGNs that are read/transmitted cyclically. For those PGNs that can only be queried once, function block MpJ1939SpecificRequest is used. Whether a PGN is queried cyclically or once can be taken from the J1939 standard. For more information, see here.
The desired PGN must be specified on the function block. In this case, the user is responsible for managing the data. For more information, see here.