:WAVeform:XYFormat:IBLock:DOUBle:XDATa?

Query Syntax

:WAVeform:XYFormat:IBLock:DOUBle:XDATa? [<starting_point_index>,[<number_of_points>]]

<starting_point_index>

Optional zero-based integer that is the starting point index.

<number_of_points>

Optional integer that is the number of point values to return. When using this parameter, the <starting_point_index> parameter is required. If this parameter is not used, it means the number of points to the end of the record.

Description

Returns the X-axis data for XY-formatted data as 64-bit (8 byte) double-precision floating-point values in an indefinite-length block. The data is sent point-by-point starting from the graticule's left side and progressing to the right side. Use the :WAVeform:XYFormat:IBLock:DOUBle:YDATa? query to return the y-axis data. Use the :WAVeform:XYFormat:POINts? query to return the number of points contained in the array.

The XY-format data format is designed for waveforms that have been sampled using unequal time separations between adjacent data points. Unequal time separations occurs with pattern waveforms or when using a precision timebase.

See Indefinite-Length Block Response Data for more information.

Returned Data Type

The :WAVeform:XYFormat:IBLock:DOUBle:XDATa? query returns double (8 bytes) values as definite-length block data. You must specify this data type in your program language's command that you use to query the data. The specifier for this data type in your programming language will likely be "d" and it is identified in this example with red text. Confirm this with your programming language's documentation. The following is an example of the command used in Python using PyVISA.

endianness = Infiniium.query(':SYSTem:BORDer?')
Infiniium.write(':SYSTem:BORDer LENDian')
data = Infiniium.query_binary_values(':WAVeform:XYFormat:IBLock:DOUBle:XDATa?',
	datatype='d',
	container=list,
	is_big_endian=False,
	header_fmt='ieee')
Infiniium.write(':SYSTem:BORDer ' + endianness)

Endianness of Returned Block Data

To correctly interpret block data, you must know the endianness (byte order) of the returned data (integers or real), and you will most likely have to specify this same endianness in your program language's command that is used to query the data. Endianness can be set to "little endian" order in which the least significant byte is sent first and the most significant byte sent last. Or, the endianness can be set to "big endian" order in which the most significant byte is sent first and the least significant byte sent last.

To specify or query the endianness setting for binary block data, use the :SYSTem:BORDer command. The endianness setting applies to all binary queries except for :DISK:FILE:READ? query.

If you plan to change Infiniium's current endian setting, it is a good practice to query Infiniium's current endian setting and restore the setting when your program completes. This will avoid other programs having errors due to assuming a particular endianness setting.

After a factory default (:SYSTem:FACTory), little endian is set. A default setup (:SYSTem:DEFault) does not affect endianness.