nqontrol.servo package¶

Module contents¶

Servo class.

class nqontrol.servo.Servo(channel, adw, applySettings=None, offset=0.0, gain=1.0, filters=None, name=None, keep_state=False)[source]¶

Bases: object

Servo object that communicates with a control channel of the ADwin.

readFromFile overwrites all other parameters.

Parameters

channel (int) – Channel used vor the Servo. Possible is 1..8 Channel number is used for input, output and process number
adw (ADwin) – For all servos of a ServoDevice to use the same ADwin object, it is necessary to pass an ADwin object.
applySettings (str or dict) – Apply settings directly from file or dict.
offset (offset) – Overall offset.
gain (float) –
filters (5 * 5 list) – Filter coefficient matrix. Default is a 0.0 matrix.
name (str) – Choose an optional name for this servo.
keep_state (bool) – Keep the current state of the running device. It will not reset or alter any configuration on ADwin.

REALTIME_DICTS = ['realtime', '_fifo']¶

DEFAULT_COLUMNS = ['input', 'aux', 'output']¶

realtime = <DictProxy object, typeid 'dict'>¶

DEFAULT_FIFO_STEPSIZE = 10¶

MAX_CHANNELS = 8¶

property channel¶

property filterStates¶

List of all filter states.

Getter: Return the filter states.
Setter: Set all filter states.
Type: list of 5*bool.

filterState(id_, enabled)¶

Enable or disable the SOS filter with number id_.

Parameters

id (int index from 0 to 4) – Index of the filter to control.
enabled (bool) – True to enable.

property auxSw¶

Switch for mixing the aux signal to the output.

Getter: Return the state of aux mixing.
Setter: Enable or disable the aux mixing.
Type: bool

property offsetSw¶

Enable or disable offset switch.

Getter: Return the state of the switch.
Setter: Enable or disable the offset.
Type: bool

property outputSw¶

Enable or disable output switch.

Getter: Return the state of the switch.
Setter: Enable or disable the output.
Type: bool

property inputSw¶

Enable or disable input switch.

Getter: Return the state of the switch.
Setter: Enable or disable the input.
Type: bool

property offset¶

Offset value in volt. (-10 to 10)

Getter: Return the offset value.
Setter: Set the offset.
Type: float

property gain¶

Overall gain factor.

Getter: Return the gain value.
Setter: Set the gain.
Type: float

property inputSensitivity¶

Input sensitivity mode (0 to 3).

The input voltage is amplified by \(2^\mathrm{mode}\).

mode	amplification	limits (V)
0	1	10
1	2	5
2	4	2.5
3	8	1.25

Getter: Return the sensitivity mode.
Setter: Set the mode.
Type: int

property auxSensitivity¶

Aux sensitivity mode (0 to 3).

The input voltage is amplified by \(2^\mathrm{mode}\).

mode	amplification	limits (V)
0	1	10
1	2	5
2	4	2.5
3	8	1.25

Getter: Return the sensitivity mode.
Setter: Set the mode.
Type: int

property filters¶

All second order sections (SOS) of all filters.

A neutral filter matrix looks like:

[ [1, 0, 0, 0, 0],
  [1, 0, 0, 0, 0],
  [1, 0, 0, 0, 0],
  [1, 0, 0, 0, 0],
  [1, 0, 0, 0, 0] ]

Use ServoDesign from openqlab.analysis to create your filters. That object you can simply pass to a servo using applyServoDesign.

Getter: Return all filter values.
Setter: Write all 5 filters to ADwin and trigger reloading.
Type: (5, 5) matrix with filter values (float).

applyServoDesign(servoDesign=None)¶

Apply filters from a ServoDesign object.

Parameters: servoDesign (openqlab.analysis.ServoDesign) – Object to apply filters from.

property lockSearch¶

Return the lock search state. Don’t confuse with locked.

0: off 1: search

Getter: Trigger a read from ADwin. Return current value.
Setter: Set new lock state. Will convert given value to bool and then back to int.
Type: int

property locked¶

Return the locked state. Whether the servo is currently in locked state.

0: not locked 1: locked

Getter: Trigger a read from ADwin. Return current value.
Setter: Set new locked state. Will convert given value to bool and then back to int. Really only makes sense to turn this off manually, not on. Still, when manually switching on, will make sure to turn off lock search.
Type: int

property relock¶

Set the lock to trigger a relock automatically when falling below or above threshold (according to greater setting). The relock parameter is either 0 or 1, can also be passed as a boolean.

Getter: Return the current value.
Setter: Set the condition.
Type: int

property lockGreater¶

Set the lock direction to either greater (True) or lesser (False) than the threshold.

Getter: Return the current value.
Setter: Set the condition.
Type: bool

property lockRampmode¶

Enable rampmode bit for lock function. If in ramp mode, the autolock will keep searching even if a lock is found. This replaces the previous ramp.

Getter: Return current rampmode bit.
Setter: Set rampmode bit True or False.
Type: bool

property lockThreshold¶

Get or set the autolock threshold.

Getter: Trigger a read from ADwin. Return the threshold.
Setter: Set the threshold.
Type: float

property lockThresholdBreak¶

Get or set the autolock threshold break. This is the tolerance value for falling out of lock.

Getter: Trigger a read from ADwin. Return the threshold break.
Setter: Set the threshold break value.
Type: float

property lockAmplitude¶

Get or set the autolock ramp amplitude. A floating point number from 0 to 10 which will be multiplied to the normalized (-1 to 1 V) ramp.

ramp_position = amplitude * iterator + offset

Getter: Trigger a read from ADwin. Return the amplitude.
Setter: Set the amplitude.
Type: float

property lockOffset¶

Get or set the autolock ramp offset. A floating point number from -10 to 10 V which will be added to the ramp.

ramp_position = amplitude * iterator + offset

Getter: Trigger a read from ADwin. Return the offset.
Setter: Set the offset.
Type: float

property lockStepsize¶

Read out the autolock stepsize.

Returns: Stepsize value.
Return type: int

property lockFrequency¶

Rough frequency of the ramp, might contain rounding errors. Calculates the frequency from the stepsize and search range of the lock. If possible, use the stepsize directly!

Getter: Set the frequency.
Setter: Get the frequency.
Type: float

autolock(search=True, relock=None, rampmode=None, amplitude=None, offset=None, frequency=None, analysis=True, **args)¶

enableRamp(amplitude=None, offset=None, frequency=None, enableFifo=True)¶

Enable the lock ramp on this servo. Intended for command line use.

Parameters

amplitude (float, optional) – Ramp amplitude from 0 to 10 V. (0 does not make too much sense, though.) Default 1.
offset (float, optional) – Ramp offset from -10 to 10 V. Default 0.
frequency (float, optional) – Ramp frequency from 1 to 100 Hz. (Can be changed in settings.)
enableFifo (bool) – Defaults to True. Possible not to enable the FIFO buffering for this servo.

disableRamp()¶: Disable the ramp on this channel. Counterpart to enableRamp.

lockAnalysis(testdata=None, raiseErrors: bool = False, tries: int = 10)¶

Analyze the threshold and direction to be used in the autolock feature. Takes in data or reads out automatically if None was provided. Determines the correct peak by analyzing median value of the AUX channel and comparing it to the signal’s maxima and minima. A peak is deemed valid if it is sufficiently different from the median value. Generally, one would expect good peaks to be much bigger than white noise, thus we deem the analysis valid using a 3 sigma criteria.

You can also use this in conjunction with the autolock command line method, e.g.

`python s = DEVICE.servo(1) s.lockAmplitude = 3 s.lockOffset = -4 s.lockFrequency = 3 s.lockAnalysis() s.autolock() `

Parameters

testdata (pandas.DataFrame, optional) – For testing purposes one can provide a pandas DataFrame to be analyzed. Please make sure it contains a ‘aux’ column. If no data is provided, it will be read out from ADwin. (by default None)
raiseErrors (bool, optional) – Can raise errors instead of logs for testing purposes. (by default False)

getSettingsDict()¶

Get a dict with all servo settings.

Returns: Return all important settings for the current servo state.
Return type: dict

saveJsonToFile(filename)¶

Save this single servo as json to a file.

Parameters: filename (str) – Filename to save the json file.

loadSettings(applySettings, keep_state=False)¶

Load settings from file or dict.

Not reading the channel, it can only be set on creating a servo object.

Parameters

applySettings (str or dict) – Settings to load for this servo.
keep_state (bool) – Apply settings, but do not send them to ADwin.

property fifoStepsize¶

Use nqontrol.Servo.enableFifo()

Trigger ADwin to write the three channels of this servo to the FIFO buffer to read it with the PC over LAN.

input, aux and output will be sent.

Getter: Number of program cycles between each data point.
Setter: Set the number or choose None to disable the FiFo output.
Type: int
Type: Setter DEPRECATED

property realtimeEnabled¶

property fifoEnabled¶

enableFifo(fifo_stepsize: Optional[int] = None)¶

disableFifo()¶: Disable the FiFo output if it is enabled on this channel.

takeData() → pandas.core.frame.DataFrame¶

Take data from ADwin.

It will return a DataFrame containing the columns input, aux and output.

Returns: returnVar
Return type: DataFrame

stopRealtimePlot()¶: Stop the realtime plot.

realtimePlot(ydata=None, refreshTime=None, multiprocessing=True)¶

Enable parallel realtime plotting.

To stop the running job call stopRealtimePlot().

Parameters

ydata (list of str) – Choose the data to be plotted: ['input', 'aux', 'output'].
refreshTime (float) – Sleeping time (s) between plot updates.

property tempFeedback¶

Return or set temperature feedback server associated with the servo.

Getter: Return the FeedbackController.
Setter: Set a new FeedbackController.
Type: FeedbackController.

tempFeedbackStart(dT=None, mtd=None, voltage_limit=None, server='127.0.0.1', port=5917, update_interval=None)¶

Start the temperature feedback server. Setup a server if it hasn’t been previously set.

Parameters

dT (float) – Description of parameter dT.
mtd (tuple) – (1, 1)
voltage_limit (float) – The maximum voltage to which one can go using the temperature control (the default is 5).
server (type) – Description of parameter server (the default is settings.DEFAULT_TEMP_HOST).
port (type) – Description of parameter port (the default is settings.DEFAULT_TEMP_PORT).
update_interval (float) – Description of parameter update_interval (the default is 1).

tempFeedbackStop()¶: Stop the tempFeedback server.