:WAVeform:YFORmat:WORD:YDATa?

Instrument:
DCA-X
DCA-M
Meas. mode:
Scope
Eye
Flex Apps:
FlexDCA
FlexRT
Y-Format Commands

Query Syntax

:WAVeform:YFORmat:WORD:YDATa?

Description

Returns the amplitude (Y-axis) data point values as 16-bit integers which is useful for long patterns where the time required to return floating-point data would be too long and the precision is not required. If measurement resolution is more important than fast transfer time, use the :WAVeform:YFORmat:FLOat:YDATa? query instead.

Use the :WAVeform:SOURce command to select data from a channel, differential channel, waveform memory, or a function.

The time at any data point:

Xtime = (Xdata)(Xincrement) + (Xorigin)

Where the X-axis increment value is given by the :WAVeform:YFORmat:XINCrement? query.

To convert raw analog-to-digital converter data:

Yamplitude = (Ydata)(conversion factor) + Yorigin

Where the conversion factor is given by the :WAVeform:YFORmat:WORD:ENCoding:YINCrement? query for converting counts to volts.

Returned Data Type

The :WAVeform:YFORmat:WORD:YDATa? query returns short int (signed) values as binary definite-length block data queries binary definite-length block data queries binary definite-length block data queries. 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 "h" 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.

Flex.read_termination = ''
Flex.write_termination = ''
endianness = Flex.query(':SYSTem:BORDER?')
Flex.write(':SYSTem:BORDER LENDian')
data = Flex.query_binary_values(':WAVeform:YFORmat:WORD:YDATa?',
	datatype='h',
	container=list,
	is_big_endian=False,
	header_fmt='ieee')
Flex.write(':SYSTem:BORDER ' + endianness)

Endianness of Returned Definite-Length Block Data

To correctly interpret definite-length block data, you must know the endianness (byte order) of the returned data (integers or real) from FlexDCA and you will must likely need 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 endiannes setting applies to all binary queries except for :DISK:FILE:READ? query.

If you plan to change FlexDCA's current endian setting, it is a good practice to query FlexDCA'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 preset (:SYSTem:FACTory), sets little endian. A default setup (:SYSTem:DEFault) does not affect endianness.

Be aware that VXI plug-and-play drivers can change the endianness setting. As a result always explicitly set the endianness in your program before transferring any binary data.

The ability to specify endianness requires FlexDCA revision A.04.00 and above. Prior to revision A.04.00, the endianness of returned block data was always LSB (Least Significant Byte) first.

Y-Format Commands
Query Description
:WAVeform:YFORmat:WORD:YDATa? 16-bit integer raw analog-to-digital converter counts
:WAVeform:YFORmat:XINCrement? The time spacing between the data points.
:WAVeform:YFORmat:POINts? Returns the number of points in the data . The value Xindex in the following equation, is the data point count, starting at zero and ending at the number of points minus one.
:WAVeform:YFORmat:XORigin? The time value of the first data point.
:WAVeform:YFORmat:WORD:ENCoding:YINCrement? For WORD formatted data, returns the counts-to-volts conversion factor.
:WAVeform:YFORmat:WORD:ENCoding:YORigin? For WORD formatted data, returns the voltage offset.
:WAVeform:YFORmat:POINts:CLIPped:HIGH? Returns the number of data points that are clipped high.
:WAVeform:YFORmat:POINts:CLIPped:LOW? Returns the number of data points that are clipped low.
:WAVeform:YFORmat:POINts:HOLes? Returns the number of data points that have void data.
:WAVeform:YFORmat:WORD:ENCoding:CHIGh? For WORD (integer) formatted data, returns the value that indicates a clipped high data point: 32,256.
:WAVeform:YFORmat:WORD:ENCoding:CLOW? For WORD (integer) formatted data, returns the value that indicates a clipped low data point: 31,744.
:WAVeform:YFORmat:WORD:ENCoding:HOLe? For WORD (integer) formatted data, returns the value that indicates a void data point: 31,232.