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Node Documentation

This section describes all the nodes in the Sweeper Module node tree organized by branch.

averaging

/averaging/sample

Properties: Read, Write

Type: Integer (64 bit)

Unit: Samples

Sets the number of data samples per sweeper parameter point that is considered in the measurement.

/averaging/tc

Properties: Read, Write

Type: Double

Unit: TC

Sets the effective number of time constants per sweeper parameter point that is considered in the measurement.

/averaging/time

Properties: Read, Write

Type: Double

Unit: Seconds

Sets the effective measurement time per sweeper parameter point that is considered in the measurement.

awgcontrol

/awgcontrol

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Enable AWG control for sweeper. If enabled the sweeper will automatically start the AWG and records the sweep sample based on the even index in hwtrigger.

bandwidth

/bandwidth

Properties: Read, Write

Type: Double

Unit: Hz

Defines the measurement bandwidth when using Fixed bandwidth mode (sweep/bandwidthcontrol=1), and corresponds to the noise equivalent power bandwidth (NEP).

bandwidthcontrol

/bandwidthcontrol

Properties: Read, Write

Type: Integer (enumerated)

Unit: None

Specify how the sweeper should specify the bandwidth of each measurement point. Automatic is recommended, in particular for logarithmic sweeps and assures the whole spectrum is covered.

Value Description
0 "manual": Manual (the sweeper module leaves the demodulator bandwidth settings entirely untouched)
1 "fixed": Fixed (use the value from sweep/bandwidth)
2 "auto": Automatic. Note, to use either Fixed or Manual mode, sweep/bandwidth must be set to a value > 0 (even though in manual mode it is ignored).

bandwidthoverlap

/bandwidthoverlap

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

If enabled the bandwidth of a sweep point may overlap with the frequency of neighboring sweep points. The effective bandwidth is only limited by the maximal bandwidth setting and omega suppression. As a result, the bandwidth is independent of the number of sweep points. For frequency response analysis bandwidth overlap should be enabled to achieve maximal sweep speed.

clearhistory

/clearhistory

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Remove all records from the history list.

device

/device

Properties: Read, Write

Type: String

Unit: None

The device ID to perform the sweep on, e.g., dev123 (compulsory parameter, this parameter must be set first).

endless

/endless

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Enable Endless mode; run the sweeper continuously.

filtermode

/filtermode

Properties: Read, Write

Type: Integer (enumerated)

Unit: None

Selects the filter mode.

Value Description
0 "application": Application (the sweeper sets the filters and other parameters automatically)
1 "advanced": Advanced (the sweeper uses manually configured parameters)

gridnode

/gridnode

Properties: Read, Write

Type: String

Unit: Node

The device parameter (specified by node) to be swept, e.g., "oscs/0/freq".

historylength

/historylength

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Maximum number of entries stored in the measurement history.

loopcount

/loopcount

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

The number of sweeps to perform.

maxbandwidth

/maxbandwidth

Properties: Read, Write

Type: Double

Unit: Hz

Specifies the maximum bandwidth used when in Auto bandwidth mode (sweep/bandwidthcontrol=2). The default is 1.25 MHz.

omegasuppression

/omegasuppression

Properties: Read, Write

Type: Double

Unit: dB

Damping of omega and 2omega components when in Auto bandwidth mode (sweep/bandwidthcontrol=2). Default is 40dB in favor of sweep speed. Use a higher value for strong offset values or 3omega measurement methods.

order

/order

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Defines the filter roll off to set on the device in Fixed and Auto bandwidth modes (sweep/bandwidthcontrol=1 and 2). It ranges from 1 (6 dB/octave) to 4 (24 dB/octave) or 8 (48 dB/octave) depending on the device type.

phaseunwrap

/phaseunwrap

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Enable unwrapping of slowly changing phase evolutions around the +/-180 degree boundary.

remainingtime

/remainingtime

Properties: Read

Type: Double

Unit: Seconds

Reports the remaining time of the current sweep. A valid number is only displayed once the sweeper has been started. An undefined sweep time is indicated as NAN.

samplecount

/samplecount

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

The number of measurement points to set the sweep on.

save

/save/csvlocale

Properties: Read, Write

Type: String

Unit: None

The locale to use for the decimal point character and digit grouping character for numerical values in CSV files: "C": Dot for the decimal point and no digit grouping (default); "" (empty string): Use the symbols set in the language and region settings of the computer.

/save/csvseparator

Properties: Read, Write

Type: String

Unit: None

The character to use as CSV separator when saving files in this format.

/save/directory

Properties: Read, Write

Type: String

Unit: None

The base directory where files are saved.

/save/fileformat

Properties: Read, Write

Type: Integer (enumerated)

Unit: None

The format of the file for saving data.

Value Description
0 "mat": MATLAB
1 "csv": CSV
2 "zview": ZView (Impedance data only)
3 "sxm": SXM (Image format)
4 "hdf5": HDF5
/save/filename

Properties: Read, Write

Type: String

Unit: None

Defines the sub-directory where files are saved. The actual sub-directory has this name with a sequence count (per save) appended, e.g. daq_000.

/save/save

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Initiate the saving of data to file. The saving is done in the background. When the save has finished, the module resets this parameter to 0.

/save/saveonread

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Automatically save the data to file immediately before reading out the data from the module using the read() command. Set this parameter to 1 if you want to save data to file when running the module continuously and performing intermediate reads.

scan

/scan

Properties: Read, Write

Type: Integer (enumerated)

Unit: None

Selects the scanning type.

Value Description
0 "sequential": Sequential (incremental scanning from start to stop value)
1 "binary": Binary (Non-sequential sweep continues increase of resolution over entire range)
2 "bidirectional": Bidirectional (Sequential sweep from Start to Stop value and back to Start again)
3 "reverse": Reverse (reverse sequential scanning from stop to start value)

settling

/settling/inaccuracy

Properties: Read, Write

Type: Double

Unit: None

Demodulator filter settling inaccuracy defining the wait time between a sweep parameter change and recording of the next sweep point. The settling time is calculated as the time required to attain the specified remaining proportion [1e-13, 0.1] of an incoming step function. Typical inaccuracy values: 10m for highest sweep speed for large signals, 100u for precise amplitude measurements, 100n for precise noise measurements. Depending on the order of the demodulator filter the settling inaccuracy will define the number of filter time constants the sweeper has to wait. The maximum between this value and the settling time is taken as wait time until the next sweep point is recorded. See programming manual for the relationship between sweep/settling/inaccuracy and sweep/settling/tc.

/settling/tc

Properties: Read, Write

Type: Double

Unit: TC

Minimum wait time in factors of the time constant (TC) between setting the new sweep parameter value and the start of the measurement. This filter settling time is derived from sweep/settling/inaccuracy. The maximum between this value and sweep/settling/time is taken as effective settling time. Note, although it is recommended to use sweep/settling/inaccuracy, it is still possible to set sweep/settling/tc directly (the parameter applied will be simply the last one set).

/settling/time

Properties: Read, Write

Type: Double

Unit: Seconds

Minimum wait time in seconds between setting the new sweep parameter value and the start of the measurement. The maximum between this value and sweep/settling/tc is taken as effective settling time.

sincfilter

/sincfilter

Properties: Read, Write

Type: Integer (64 bit)

Unit: None

Enables the sinc filter if the sweep frequency is below 50 Hz. This will improve the sweep speed at low frequencies as omega components do not need to be suppressed by the normal low pass filter.

start

/start

Properties: Read, Write

Type: Double

Unit: Many

The start value of the sweep parameter.

stop

/stop

Properties: Read, Write

Type: Double

Unit: Many

The stop value of the sweep parameter.

xmapping

/xmapping

Properties: Read, Write

Type: Integer (enumerated)

Unit: None

Selects the spacing of the grid used by sweep/gridnode (the sweep parameter).

Value Description
0 "linear": Linear
1 "log": Logarithmic distribution of sweep parameter values