BACnetReadFile (FUN)

FUNCTION BACnetReadFile : IEC_BACNET_STATUS

Sends an AtomicReadFile request.

Sends a request to read the contents of the specified file beginning from the specified position. The file may be accessed as records or as a stream of octets that is defined by the contents of File_Access_Method property of the File object. Since the present version of this API does not support a default processing of this service, the user application has to include a Hook procedure to process it. This routine may control APDU properties like APDU length, segmentation, and timeout for both request and response. This routine can execute asynchronously, i.e. this routine will return to the caller before the BACnet reply comes so that the applications can keep running. In this case the response information will be received by the thread which is responsible for receiving asynchronous responses. An optional BACNET_READ_FILE_COMPLETE_CB routine, which is provided by the BACnet application, shall be used to process this information. If a number of asynchronous requests are sent, the responses shall be queued and identified by the transaction handles. If application does not supply the BACNET_READ_FILE_COMPLETE_CB routine; then the BACnetReadFile routine sends a request and waits for reply.

Asynchron call, which fills pResult with the call result in an asynchronus manner. As soon as pResultStatus is IEC_BACNET_STATUS.BACNET_STATUS_OK the data in pResult is valid.

InOut:

Scope	Name	Type	Comment
Return	BACnetReadFile	IEC_BACNET_STATUS	A status indicating if the operation worked.
Input	pSourceAddress	POINTER TO IEC_BACNET_ADDRESS	If the BACnet application has only one device constructed and installed, this can be 0. In this case the MAC address of this device will be used. Otherwise this shall be the MAC address returned on device object construction.
	pDestinationAddress	POINTER TO IEC_BACNET_ADDRESS	This is the MAC address of the device to which the request should be sent.
	pReadInfo	POINTER TO IEC_BACNET_READ_FILE_INFO	A pointer to hold the request information data structure. This data structure contains the objectID, File Access Type (IEC_BACNET_FILE_ACCESS_TYPE.FILE_ACCESS_STREAM or IEC_BACNET_FILE_ACCESS_TYPE.FILE_ACCESS_RECORD) and Read File Range information.
	pAPDUParams	POINTER TO IEC_BACNET_APDU_PROPERTIES	A pointer to the APDU-Properties structure which sets APDU properties for this transaction only. This does not change global defaults or settings for the application APDU Properties. This argument may be 0. In this case APDU properties are used which were specified in the device object properties of the applications device which sends the request.
	pResult	POINTER TO IEC_BACNET_READ_FILE_RESULT	A pointer to a buffer to hold the response data if successful reading (datatype IEC_BACNET_READ_FILE_RESULT). This pointer may be 0 if the asynchron call is used. In this case the memory for the response is allocated by the API and the application is responsible to release it with a call to BACnetFreeStackAllocatedMemory if the buffer is no longer needed.
	pTransactionToken	POINTER TO BACnetAsyncTransactionToken	Transaction token of the asynchronous call - see BACnetAsyncTransactionToken.
	pError	POINTER TO IEC_BACNET_ERROR	A pointer to a structure to hold BACnet Error information. pError may be 0 if the application isn’t interested in detailed error information.