finslib_memory_area_read_bit( sys, start, data, num_bit );
||A pointer to a structure with the FINS context|
||An ASCII string describing the first memory element to retrieve|
||Pointer to the buffer where the result must be stored|
||The number of bits to return|
||A return value from the list
finslib_memory_area_read_bit() can be used to retrieve a block of bits from a memory area in a remote PLC. The connection with the PLC should already be present before this function is called.
Data is transferred unmodified from the FINS data stream to the caller supplied buffer. Enough dataspace is the responsibility of the calling function, but
finslib_memory_area_read_word() will return an error if a NULL pointer is provided for data storage.
The start of the memory area is provided as an ASCII string which represents the starting address in human readable format. Example formats are
The requested number of bits is not limited by the amount of data a PLC can send in one FINS packet because
finslib_memory_area_read_bit() will automatically use multiple request at the FINS layer if the dataset will be too large.
The return value is either
FINS_RETVAL_SUCCESS when the function succeeded, or one of the other
FINS_RETVAL_ values if an eror occurs. In the latter case the data in the return buffer is unreliable and should not be used.