contrast.motors package

Module contents

Provides the Motor base class and derived motor classes.

Does not automatically load hardware-specific submodules or classes as these might have special dependencies that aren’t available everywhere.

contrast.motors.all_are_motors(seq)

Function which returns True if all objects in seq are instances of Motor or its subclasses.

Parameters:seq – List or tuple of objects to check

Submodules

contrast.motors.Motor module

class contrast.motors.Motor.Motor(scaling=1.0, offset=0.0, dial_limits=(None, None), user_format='%.2f', dial_format='%.2f', **kwargs)

Bases: contrast.Gadget.Gadget

General base class for motors.

Motors have dial and user positions, which are related by an offset and a scaling factor. The user position is supposed to be used in all macros and movements. The dial position is hard coded in the Motor subclass to closely reflect what the underlying device quotes.

user = dial * scaling + offset,
dial = (user - offset) / scaling

The user position can be changed, which updates the offset but not the scaling. In the same way, limits on the user position are internally converted to dial limits, such that setting the user position leaves the dial limits unchanged.

Parameters:

• scaling – Scaling factor from dial to user position
• offset – Offset from scaled dial to user position
• dial_limits – Motor limits in dial positions
• user_format – Format string for presenting user positions
• dial_format – Format string for presenting dial positions
• **kwargs – Passed on to base class constructor

dial_position

Override this property, which sets or gets the dial position.

Return type:float

busy()

Overrides this method, which reports on whether or not the motor is busy.

Return type:bool

stop()

Override this method, which stops the motor.

class contrast.motors.Motor.DummyMotor(velocity=None, dial_position=None, *args, **kwargs)

Bases: contrast.motors.Motor.Motor

Dummy motor which can be harmlessly moved with a velocity of 1 / s.

class contrast.motors.Motor.MotorBookmark(name, motors, positions=None)

Bases: object

A bookmark is a set of motor dial positions which together have some significance, for example a sample position or an attenuetor combination.

Parameters:

• name – Name given to the MotorBookmark
• motors (list, tuple) – The motor instances to bookmark.
• positions (list, tuple) – List of positions to bookmark.

class contrast.motors.Motor.MotorMemorizer(filepath=None, **kwargs)

Bases: contrast.Gadget.Gadget

Saves or loads motor scaling, offsets, and limits, as well as any defined bookmarks to or from file.

Parameters:

• filepath (str) – Path to file where motor information will be dumped
• **kwargs – Passed on to the base class

load()

Loads memorized motor configurations from self.filepath, and applies to matching motors.

dump()

Dumps motor configurations for all motors to self.filepath.

class contrast.motors.Motor.Mv(*args)

Bases: object

This class generates the macro `mv`

Move one or more motors.

mvr <motor1> <position1> <motor2> <position2> ...

class contrast.motors.Motor.Mvd

Bases: object

This class generates the macro `mvd`

Move one or more motors to an abolute dial position. Not implemented.

class contrast.motors.Motor.Mvr(*args)

Bases: contrast.motors.Motor.Mv

This class generates the macro `mvr`

Move one or more motors relative to their current positions.

mvr <motor1> <position1> <motor2> <position2> ...

class contrast.motors.Motor.Umv(*args)

Bases: contrast.motors.Motor.Mv

This class generates the macro `umv`

Like mv, but prints the current position while moving, and returns when the move is complete.

class contrast.motors.Motor.Umvr(*args)

Bases: contrast.motors.Motor.Mvr, contrast.motors.Motor.Umv

This class generates the macro `umvr`

Like umv, but in positions relative to the current ones.

class contrast.motors.Motor.Wm(*args)

Bases: object

This class generates the macro `wm`

Print the positions of one or more motors.

wm <motor1> <motor2> ...

class contrast.motors.Motor.WmS(*args)

Bases: contrast.motors.Motor.Wm

This class generates the macro `wms`

Silent ‘where motor’. Print the positions of one or more motors but do not print any output.

wms <motor1> <motor2> ...

class contrast.motors.Motor.Wa

Bases: contrast.motors.Motor.Wm

This class generates the macro `wa`

Print the positions of all motors available at the current user level.

class contrast.motors.Motor.LsM

Bases: object

This class generates the macro `lsm`

List available motors.

class contrast.motors.Motor.SetLim(*args)

Bases: object

This class generates the macro `setlim`

Set limits on motors.

setlim <motor1> <lower 1> <upper 1> ...

Also saves new limits to all available MotorMemorizer objects.

class contrast.motors.Motor.SetPos(*args)

Bases: object

This class generates the macro `setpos`

Sets user position on motors.

setpos <motor1> <pos1> ...

Also saves new user positions to all available MotorMemorizer objects.

class contrast.motors.Motor.BookmarkMacroBase(*args)

Bases: object

Base class for bookmark macros, which parses arguments into a list of MotorBookmark objects. If none are given, all bookmarks are included.

class contrast.motors.Motor.LsBook(*args)

Bases: contrast.motors.Motor.BookmarkMacroBase

This class generates the macro `lsbook`

Lists the currently defined bookmarks or the contents of a specific bookmark.

lsbook [<bookmark name>]

class contrast.motors.Motor.Bookmark(name, *args)

Bases: object

This class generates the macro `bookmark`

Bookmarks the specified motors at their current dial positions.

bookmark <'bookmark name'> <motor 1> <motor 2> ...

Also saves existing bookmarks to all available MotorMemorizer objects.

class contrast.motors.Motor.Restore(*args)

Bases: contrast.motors.Motor.BookmarkMacroBase

This class generates the macro `restore`

Restore a bookmarked position by moving all motors there.

class contrast.motors.Motor.RmBook(*args)

Bases: contrast.motors.Motor.BookmarkMacroBase

This class generates the macro `rmbook`

Delete one or all bookmarks defined with the bookmark command.

rmbook [<bookmark 1> <bookmark 2> ...]

Also updates all available MotorMemorizer instances.

contrast.motors.PseudoMotor module

Provides base and example classes for pseudo motors, which are combinations of other motors.

class contrast.motors.PseudoMotor.PseudoMotor(motors, dry_run=False, *args, **kwargs)

Bases: contrast.motors.Motor.Motor

Pseudo motor base class.

Abstract base class for pseudo motors. The logic of pseudo motors needs some attention.

Parameters:

• motors – The underlying physical motors.
• dry_run (bool) – Don’t move any physical motors, just print calculated positions.

physicals()

Current positions of physical motors.

Returns:Positions Return type:list

calc_pseudo(physicals)

Override this method, which calculates the pseudo position for given physical positions.

Parameters:physicals – Physical positions Returns:Pseudo position

calc_physicals(pseudo)

Override this method, which calculates the physical positions for a target pseudo position.

Parameters:pseudo – Target pseudo position Returns:Physical positions.

class contrast.motors.PseudoMotor.ExamplePseudoMotor(motors, dry_run=False, *args, **kwargs)

Bases: contrast.motors.PseudoMotor.PseudoMotor

Example pseudo motor which implements the difference between two motors.

Abstract base class for pseudo motors. The logic of pseudo motors needs some attention.

Parameters:

• motors – The underlying physical motors.
• dry_run (bool) – Don’t move any physical motors, just print calculated positions.

contrast.motors.E727 module

Provides a Motor subclass for the PI E727 piezo driver.

class contrast.motors.E727.E727Motor(device, axis, **kwargs)

Bases: contrast.motors.Motor.Motor

Single axis on the E727.

Parameters:

• device (str) – Path to the Tango device
• axis (int) – Axis number of the E727 controller
• **kwargs – Passed to the Motor base class

contrast.motors.KukaMotor module

Provides a Motor interface to the MAX IV Kuka robot Tango device.

class contrast.motors.KukaMotor.KukaRobot(tango_path, names=['gamma', 'delta', 'radius'])

Bases: object

Managing class which coordinates movements of the robot in polar coordinates. The manager’s role is to avoid trying to move more than one robot motor at a time, which would not be compatible with the controller.

This class owns three KukaMotor instances, which are returned on iteration:

gamma, delta, radius = KukaRobot('path/to/device',
                                 names=['gamma, 'delta', 'radius'])

Parameters:

• tango_path (str) – Path to the underlying Tango device
• names (list, tuple) – Names to assign to the three polar motors

move_me(motor, pos)

Method which makes sure that only one polar axis is moved at a time. For now, this is done by blocking until the device is standing still. Should perhaps be threaded or so, but works like this for scanning for example the two polar angles in a mesh.

Parameters:

• motor – Motor instance to move, typically self for the calling KukaMotor.
• pos (float) – Target position

class contrast.motors.KukaMotor.KukaMotor(manager, **kwargs)

Bases: contrast.motors.Motor.Motor

Single motor as exposed by the KukaRobot class.

Parameters:

• manager – Managing KukaRobot instance
• **kwargs – Passed on to the base class constructor

move(pos)

This motor needs to override the base class move, because move commands must be accepted even if the motor is busy.

Parameters:pos (float) – Target position

contrast.motors.LC400 module

Provides a Motor subclass for the Npoint LC400 piezo driver, and a helper class for generating waveforms. Relies on the Tango server developed at MAX IV (available on request!):

• https://gitlab.maxiv.lu.se/kits-maxiv/lib-maxiv-npoint-lc400
• https://gitlab.maxiv.lu.se/kits-maxiv/dev-maxiv-npoint-lc400

class contrast.motors.LC400.LC400Motor(device, axis, **kwargs)

Bases: contrast.motors.Motor.Motor

Single axis on the LC400.

Parameters:

• device (str) – Path to the underlying Tango device.
• axis – Axis number on the Tango controller
• **kwargs – Passed on to the base class constructor

class contrast.motors.LC400.LC400Waveform(axis, startpoint, endpoint, scanpoints, exposuretime, latencytime, accelerationtime, decelerationtime=None, startvelocity=None, endvelocity=None)

Bases: object

Class to generate waveform configs for the LC400 piezo controller. It generates a JSON string, that can be send to the LC400 Tango Server to configure the waveform.

reset_json()

Create three waveform jsons which deconfigure each channel:

r1, r2, r2 = reset_json()

contrast.motors.SmaractMotor module

Provides a Motor subclass for Smaract positioners. All numbers in micrometers.

Controls these via a MAX IV Tango device, https://gitlab.maxiv.lu.se/kits-maxiv/dev-maxiv-mcs

class contrast.motors.SmaractMotor.SmaractLinearMotor(device, axis, velocity=None, **kwargs)

Bases: contrast.motors.Motor.Motor

Single Smaract motor axis.

Parameters:

• device (str) – Path to the MCS Tango device
• axis (int) – Axis number on the controller
• velocity (float) – Initialize velocity, defaults to None
• **kwargs – Passed on to the Motor base class

contrast.motors.TangoAttributeMotor module

Provides a general Motor interface to any Tango attribute.

class contrast.motors.TangoAttributeMotor.TangoAttributeMotor(device, attribute, force_read=True, **kwargs)

Bases: contrast.motors.Motor.Motor

Motor interface to any Tango attribute, so that anything can be scanned. These motors cannot be stopped and are never considered busy.

Parameters:

• device (str) – Path to the Tango device
• attribute (str) – Name of the Tango attribute
• **kwargs – Passed to the Motor base class

contrast.motors.TangoMotor module

Provides a Motor interface to standard Tango motors.

class contrast.motors.TangoMotor.TangoMotor(device, **kwargs)

Bases: contrast.motors.Motor.Motor

Single Tango motor.

Parameters:

• device (str) – Path to the Tango device
• **kwargs – Passed to the Motor base class

dial_limits

Overridden to expose the limits on the Pool motor.