dio_get_historic_scaling_c

	status.i4.v = dio_get_historic_scaling_c(device_index.i4.v,
						 property.i2.v,
						 clinks.u4.v,
						 scaling_data.g.v)

	This routine retrieves scaling information for a device/property
	for a given date.

	device_index	device index 
	property	property index (constants are in 'dbprops')
			(PRREAD -> reading property,
			 PRSET -> setting property)
	clinks		date of interest in clinks
	scaling_data	returned scaling data
			(reading (PRREAD) -> PDB_RS structure,
			 setting (PRSET) -> PDB_RS structure)

	This function returns ACNET status values as follows:

	OK			success
	SQL_xxx			error retrieving scaling information

	This function requires the following include files:

	diolib_h, acnet_errors_h

	Related functions:

	dio_raw_to_scaled_historic_c, dio_historic_data_length_c,
	dio_historic_raw_data_type_c, dio_pdb_to_scaling_info_c,
	dio_get_pdb, dio_pdb_sts, dio_pdb_ctl, dio_scaling,
	dio_data_type_info_c

	C/C++ usage:

	short	property = PRREAD;
	int	status;
	int	device_index = 27235;
	unsigned int	clinks = DATE_IN_CLINKS;
	PDB_RS	scaling_info;

	status = dio_get_historic_scaling_c(device_index,property,clinks,
					    (void *) &scaling_info);