CAN_Write

PCAN-Basic

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PCAN-Basic Documentation

CAN_Write

Transmits a CAN message.

Syntax

C++

TPCANStatus __stdcall CAN_Write(
        TPCANHandle Channel,
        TPCANMsg* MessageBuffer
);

Parameters

Parameters	Description
Channel	The handle of a PCAN Channel (see TPCANHandle).
MessageBuffer	A TPCANMsg buffer containing the CAN message to be sent.

Returns

The return value is a TPCANStatus code. PCAN_ERROR_OK is returned on success. The typical errors in case of failure are:

PCAN_ERROR_ILLPARAMVAL:	Indicates that the parameters passed to the function are invalid. Check the value of the MessageBuffer; it should point to a TPCANMsg structure.
PCAN_ERROR_INITIALIZE:	Indicates that the given PCAN channel was not found in the list of initialized channels of the calling application.
PCAN_ERROR_BUSOFF:	Indicates a bus error within the given PCAN Channel. The hardware is in bus-off status.
PCAN_ERROR_QXMTFULL:	Indicates that the transmit queue of the Channel is full.

Remarks

If a bus-off error occur, an application cannot use the channel to communicate anymore, until the CAN controller is reset. With PCAN-Basic it is not possible to reset the CAN controller through a function directly. Consider using the PCAN-Basic property PCAN_BUSOFF_AUTORESET which instructs the API to automatically reset the CAN controller when a bus-off state is detected.

Another way to reset errors like BUSOFF, BUSHEAVY, and BUSLIGTH, is to uninitialize and initialise again the channel used. This causes a hardware reset, but only when no more clients are connected to that channel.

Example

The following example shows the use of CAN_Write on the channel PCAN_USBBUS1. In case of failure, the returned code will be translated to a text (according with the operating system language) in English, German, Italian, French or Spanish, and it will be shown to the user.

Note: It is assumed that the channel was already initialized.

C++:

TPCANMsg msg;
TPCANStatus result;
char strMsg[256];

// A CAN message is configured
//
msg.ID = 0x100;
msg.MSGTYPE = PCAN_MESSAGE_STANDARD;
msg.LEN = 3;
msg.DATA[0] = 1;
msg.DATA[1] = 2;
msg.DATA[2] = 3;

// The message is sent using the PCAN-USB Channel 1
//
result = CAN_Write(PCAN_USBBUS1, &msg);
if(result != PCAN_ERROR_OK)
{
    // An error occurred, get a text describing the error and show it
    //
    CAN_GetErrorText(result, 0, strMsg);
    MessageBox(strMsg);
}
else
    MessageBox("Message sent successfully");