CAPLfunctionC2xInitPacket

C2xInitPacket

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CAPL Functions » Car2x » C2xInitPacket

Function Syntax

• long C2xInitPacket( void );
• long C2xInitPacket( char protocolDesignator[] );
• long C2xInitPacket( char protocolDesignator[], char packetTypeDesignator[] );
• long C2xInitPacket( long packetToCopy );
• long C2xInitPacket( long rawDataLength, byte rawData[] );
• long C2xInitPacket( long rawDataLength, char rawData[] );
• long C2xInitPacket( long rawDataLength, struct * rawDataStruct );

Description

This function creates a new WLAN packet. Other functions can access the newly created packet with the returned handle. Protocol fields that are marked as InitProtocol in the protocol description are initialized.

Parameters

• protocolDesignator: Designator of the protocol, which should be used for initialization.
• packetTypeDesignator: Designator of the packet type.
• packetToCopy: Handle of a packet created with C2xInitPacket before or handle of a packet received within a callback (OnC2xPacket). The header and the data of this packet are copied to the newly created packet.
• rawDataLength: Length of rawData in bytes.
• rawData/rawDataStruct: Raw data of a WLAN packet that is used to initialize the new packet.

Return Values

With C2xGetLastError, you can check if the function has been processed successfully.

• 0: —
• ≠0: Handle of the created packet.

Example

long packetHandle;
char error[100];
byte macAddress[6] = { 0x20, 0x00, 0x00, 0x00, 0x00, 0x01 };

// create packet
packetHandle = C2xInitPacket("geo_cnh");
if (C2xGetLastError() == 0)
{
  // set protocol fields
  C2xSetTokenData(packetHandle, "wlan", "address2", 6, macAddress);
  C2xSetTokenData(packetHandle, "eth", "source", 6, macAddress);

  // set CNH values
  C2xSetTokenInt(packetHandle, "geo_cnh", "lpvSpeed", 100);
  C2xSetTokenInt(packetHandle, "geo_cnh", "lpvHeading", 1800);
  C2xSetTokenInt(packetHandle, "geo_cnh", "lpvAltitude", 0);

  // Complete and send packet
  C2xCompletePacket(packetHandle);
  C2xOutputPacket(packetHandle);

  // release packet
  C2xReleasePacket(packetHandle);
}
else
{
  C2xGetLastErrorText(elCount(error), error);
  write("Error: %s", error);
}

See Also: C2xGetLastError

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