JBus Class Reference

#include <jbus.h>

Public Member Functions
virtual int	init (std::string filename, int flags, void *p_other)
virtual int	receive (int fd, j1939_pdu_typ *pdu, int *extended, int *slot)
virtual int	close_conn (int *pfd)
virtual	~JBus ()

Detailed Description

Primary class used to communicate with the CAN card port.

This class is responsible for initializing the connection with the port to the CAN driver which enables communication with the CAN card. It is also responsible for sending and receiving messages to and from the CAN card port. Writing is then handled by device-level register commands.

Constructor & Destructor Documentation

~JBus()

JBus::~JBus ( )

virtual

Virtual destructor.

Member Function Documentation

close_conn()

int JBus::close_conn ( int *  pfd )

virtual

Wrapper for the close call.

Sets the input "file descriptor" to NULL, so that attempts to close twice can be caught. Requires passing address of fd/handle to this routine.

Note: Some drivers are not file structured and may require disconnect functions to be called.

Parameters

pfd	pointer to file descriptor

Returns

-1 if handle is NULL, otherwise returns the value from the close of the real fd

init()

int JBus::init ( std::string  filename, int  flags, void *  p_other  )

virtual

Initialize the jbus connection.

Opens a connection with the CAN card. If access to channel and connection IDs used by the CAN driver are actually required outside of the CAN driver, and its client calls, we must call operations on the "fd" returned by can_open (actually a pointer) to retrieve them.

Parameters

filename	location of the CAN data stream
flags	flag variable for the open() process. If RDONLY, this method will arm the pulse
p_other	pointer in case other information is needed for some driver initialization

Returns

file descriptor that will be used in all subsequent calls, -1 if an error was experienced

receive()

int JBus::receive ( int  fd, j1939_pdu_typ *  pdu, int *  extended, int *  slot  )

virtual

Update a PDU object with information from the can card.

Parameters

fd	file descriptor acquired while opening the connection
pdu	pointer to a generic PDU message that will be updated with information received from the CAN card
extended	updated to be 1 if the identifier is in extended (29 bit) format, 0 if it is in the unextended (11 bit) format
slot	external slot, internal type

Returns

J1939_CAN_MESSAGE_ERROR (0) on can_read failure; otherwise returns the (positive) number of bytes in the message. no fatal error conditions are recognized.

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The documentation for this class was generated from the following files:

• include/jbus/jbus.h
• include/jbus/jbus.cpp