WriteFD

PCAN-Basic

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PCAN-Basic Documentation

WriteFD

Transmits a CAN message using a FD capable PCAN Channel.

Syntax

Pascal OO

class function WriteFD(
    Channel: TPCANHandle;
    var MessageBuffer: TPCANMsgFD
    ): TPCANStatus;

[DllImport("PCANBasic.dll", EntryPoint = "CAN_WriteFD")]
public static extern TPCANStatus WriteFD(
    [MarshalAs(UnmanagedType.U1)]
    TPCANHandle Channel,
    ref TPCANMsgFD MessageBuffer);

C++ / CLR

[DllImport("PCANBasic.dll", EntryPoint = "CAN_WriteFD")]
static TPCANStatus WriteFD(
    [MarshalAs(UnmanagedType::U1)]
    TPCANHandle Channel,
    TPCANMsgFD %MessageBuffer);

Visual Basic

<DllImport("PCANBasic.dll", EntryPoint:="CAN_WriteFD")> _
Public Shared Function WriteFD( _
    <MarshalAs(UnmanagedType.U1)> _
    ByVal Channel As TPCANHandle, _
    ByRef MessageBuffer As TPCANMsgFD) As TPCANStatus
End Function

Python

def WriteFD(
    self,
    Channel,
    MessageBuffer)

Parameters

Parameters	Description
Channel	The handle of a FD capable PCAN Channel (see TPCANHandle).
MessageBuffer	A TPCANMsgFD 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 method are invalid. Check the value of the MessageBuffer; it should point to a TPCANMsgFD structure.
PCAN_ERROR_ILLOPERATION:	Indicates that the PCAN Channel passed to the method was not initialized using InitializeFD (plain function: CAN_InitializeFD).
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

The use of Write and WriteFD are mutually exclusive. The PCAN Channel passed to this method must be initialized using InitializeFD (plain function: CAN_InitializeFD). Otherwise the error PCAN_ERROR_ILLOPERATION is returned.

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 method 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, BUSWARNING, and BUSPASSIVE, is to uninitialize and initialise again the channel used. This causes a hardware reset.

Python Notes

Class-Method: Unlike the .NET Framework, under Python a variable has to be instantiated with an object of type PCANBasic in order to use the API functionality.
Python's first argument convention: Under Python, 'self' is a parameter that is automatically included within the call of this method, within a PCANBasic object and hasn't to be indicated in a method call. This parameter represents the calling object itself.

Example

The following example shows the use of the method WriteFD 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 using the method InitializeFD.

C#:

TPCANStatus result;
StringBuilder strMsg;
TPCANMsgFD msg;

strMsg = new StringBuilder(256);

// A CAN message is created. The Data field (64 bytes)
// of the message must also be created
//
msg = new TPCANMsgFD();
msg.DATA = new Byte[64];

// A CAN message is configured
//
msg.ID = 0x100;
msg.MSGTYPE = TPCANMessageType.PCAN_MESSAGE_STANDARD | TPCANMessageType.PCAN_MESSAGE_FD;

// DLC 9 means 12 data bytes
//
msg.DLC = 9;
for(byte i=0; i < 12; i++)
    msg.DATA[i] = i;

// The message is sent using the PCAN-USB Channel 1
//
result = PCANBasic.WriteFD(PCANBasic.PCAN_USBBUS1, ref msg);
if (result != TPCANStatus.PCAN_ERROR_OK)
{
    // An error occurred, get a text describing the error and show it
    //
    PCANBasic.GetErrorText(result, 0, strMsg);
    MessageBox.Show(strMsg.ToString());
}
else
    MessageBox.Show("Message sent successfully");

C++/CLR:

TPCANStatus result;
StringBuilder^ strMsg;
TPCANMsgFD^ msg;

strMsg = gcnew StringBuilder(256);

// A CAN message is created. The Data field (64 bytes)
// of the message must also be created
//
msg = gcnew TPCANMsgFD();
msg->DATA = gcnew array<Byte>(64);

// A CAN message is configured
//
msg->ID = 0x100;
msg->MSGTYPE = TPCANMessageType::PCAN_MESSAGE_STANDARD | TPCANMessageType::PCAN_MESSAGE_FD;

// DLC 9 means 12 data bytes
//
msg->DLC = 9;
for(Byte i=0; i < 12; i++)
    msg->DATA[i] = i;

// The message is sent using the PCAN-USB Channel 1
//
result = PCANBasic::WriteFD(PCANBasic::PCAN_USBBUS1, *msg);
if (result != TPCANStatus::PCAN_ERROR_OK)
{
    // An error occurred, get a text describing the error and show it
    //
    PCANBasic::GetErrorText(result, 0, strMsg);
    MessageBox::Show(strMsg->ToString());
}
else
    MessageBox::Show("Message sent successfully");

Visual Basic:

Dim result As TPCANStatus
Dim strMsg As StringBuilder
Dim msg As TPCANMsgFD

strMsg = New StringBuilder(256)

' A CAN message is created. The Data field (64 bytes)
' of the message must also be created
'
msg = New TPCANMsgFD
msg.DATA = CType(Array.CreateInstance(GetType(Byte), 64), Byte())

' A CAN message is configured
'
msg.ID = &H100
msg.MSGTYPE = TPCANMessageType.PCAN_MESSAGE_STANDARD Or TPCANMessageType.PCAN_MESSAGE_FD

' DLC 9 means 12 data bytes
'
msg.DLC = 9
For i As Byte = 0 To 11
    msg.DATA(i) = i
Next

' The message is sent using the PCAN-USB Channel 1
'
result = PCANBasic.WriteFD(PCANBasic.PCAN_USBBUS1, msg)
If result <> TPCANStatus.PCAN_ERROR_OK Then
    ' An error occurred, get a text describing the error and show it
    '
    PCANBasic.GetErrorText(result, 0, strMsg)
    MessageBox.Show(strMsg.ToString)
Else
    MessageBox.Show("Message sent successfully")
End If

Pascal OO:

var
    result : TPCANStatus;
    strMsg: array [0..256] of Char;
    msg: TPCANMsgFD;
    I: Integer;
begin
    // A CAN message is configured
    //
    msg.ID := $100;
    msg.MSGTYPE := TPCANMessageType(Byte(PCAN_MESSAGE_STANDARD) OR Byte(PCAN_MESSAGE_FD));

    // DLC 9 means 12 data bytes
    //
    msg.DLC := 9;
    for I:=0 To 11 do
        msg.DATA[I] := I;

    // The message is sent using the PCAN-USB Channel 1
    //
    result := TPCANBasic.WriteFD(TPCANBasic.PCAN_USBBUS1,msg);
    If (result <> PCAN_ERROR_OK) Then
    begin
        // An error occurred, get a text describing the error and show it
        //
        TPCANBasic.GetErrorText(result, 0, strMsg);
        MessageBox(0, strMsg, 'Error',MB_OK);
    end
    else
        MessageBox(0,'Message sent successfully','Success', MB_OK);

Python:

# A CAN message is configured
#
msg = TPCANMsgFD()
msg.ID = 0x100
msg.MSGTYPE = PCAN_MESSAGE_STANDARD.value | PCAN_MESSAGE_FD.value

# DLC 9 means 12 data bytes
#
msg.DLC = 9
for i in range(12):
    msg.DATA[i] = i

#  The message is sent using the PCAN-USB Channel 1
#
result = objPCAN.WriteFD(PCAN_USBBUS1,msg)
if result != PCAN_ERROR_OK:
    # An error occurred, get a text describing the error and show it
    #
    result = objPCAN.GetErrorText(result)
    print result
else:
    print "Message sent successfully"