METHOD Read : SysTypes.RTS_IEC_RESULT
This method can be implemented for reading data from a stream like object. The return value can either be:
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ERR_OK: reading succeeded, udiNrBytes is > 0
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ERR_PENDING: reading is temporarily not possible, udiNrBytes = 0
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Any other error code: reading failed, reason see error code, udiNrBytes = 0
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InOut:
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Scope
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Name
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Type
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Comment
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Return
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Read
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SysTypes.RTS_IEC_RESULT
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Input
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pbyBuffer
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POINTER TO BYTE
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A buffer where the data should be written to by the callee. The callee must always write the this buffer starting at offset 0.
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udiMaxNrBytes
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UDINT
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The maximal number of bytes that should be written to pbyBuffer by the callee.
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Output
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udiNrBytes
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UDINT
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The number of bytes that were read by the callee. A value of 0 signals that the end of the stream was reached or that an error happened. The according decision between error or end of stream is made by evaluating the return value.
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