TraceMgrPacketReadFirst (FUN)

FUNCTION TraceMgrPacketReadFirst : RTS_IEC_HANDLE

Reads the contents of the first record.

Note

if the result code is ERR_ENTRIES_REMAINING, data has been successfully copied to pTraceBuffer, but more data can be read by a subsequent call. (Either because the destination buffer was too small, or because new data has been recorded in the mean time.)

Note

You should call TraceMgrPacketReadBegin before calling this function, to make sure any outstanding trace values are written to the trace buffers.

Note

Data is always returned in little endian byte order even if the device has big endian byte order.

InOut:

Scope	Name	Type	Comment
Return	TraceMgrPacketReadFirst	RTS_IEC_HANDLE	Returns the runtime system error code (see CmpErrors.library): ERR_PARAMETER if hPacket is not a valid packet handle ERR_NO_OBJECT if the packet does not have a single record ERR_NOTINITIALIZED if the packet is not complete ERR_TIMEOUT if reading took too long ERR_ENTRIES_REMAINING if more data can be read by a subsequent call (this is not an error)
Input	hPacket	RTS_IEC_HANDLE	The trace packet handle
Inout	pTraceBuffer	TraceRecordEntry	Pointer to the destination buffer
	pulReadBytes	UDINT	Size of the destination buffer in bytes (in), number of bytes copied (out)
	pResult	RTS_IEC_RESULT	The result code