pcdsdevices.ccm.CCM

class pcdsdevices.ccm.CCM(*, prefix: str | None = None, in_pos: float, out_pos: float, **kwargs)

The full CCM assembly.

This requires a huge number of motor pv prefixes to be passed in. Pay attention to this docstring because most of the arguments are in the kwargs.

Parameters:

• prefix (str, optional) – Devices are required to have a positional argument here, but this is not used. If provided, it should be the same as alio_prefix.

• in_pos (float, required keyword) – The x position to consider as “inserted” into the beam.

• out_pos (float, required keyword) – The x position to consider as “removed” from the beam.

• alio_prefix (str, required keyword) – The PV prefix of the Alio motor, e.g. XPP:MON:MPZ:07A

• theta2fine_prefix (str, required keyword) – The PV prefix of the motor that controls the fine adjustment of the of the second crystal’s theta angle.

• theta2coarse_prefix (str, required keyword) – The PV prefix of the motor that controls the coarse adjustment of the of the second crystal’s theta angle.

• chi2_prefix (str, required keyword) – The PV prefix of the motor that controls the adjustment of the of the second crystal’s chi angle.

• x_down_prefix (str, required keyword) – The prefix for the downstream ccm x translation motor (x1).

• x_up_prefix (str, required keyword) – The prefix for the upstream ccm x translation motor (x2).

• y_down_prefix (str, required keyword) – The prefix for the downstream ccm y translation motor (y1).

• y_up_north_prefix (str, required keyword) – The prefix for the north upstream ccm y translation motor (y2).

• y_up_south_prefix (str, required keyword) – The prefix for the south upstream ccm y translation motor (y3).

• acr_status_pv_index (int) – The index for the energy request PV in the case of the acr status wait. Default: 2.

• acr_status_suffix (str) – The suffix for the ACR status energy change move. Default to ‘AO805’

Ophyd Device Components

Attribute	Class	Suffix	Docs	Kind	Notes
theta0_deg (FCpt)	EpicsSignal	{_constants_prefix}:THETA0	Reference angle for the first crystal in deg.	config	Inherited from CCMConstantsMixin
dspacing (FCpt)	EpicsSignal	{_constants_prefix}:DSPACING	Crystal lattice spacing.	config	Inherited from CCMConstantsMixin
gr (FCpt)	EpicsSignal	{_constants_prefix}:GR	The radius of the sapphire ball connected to the Alio stage in mm.	config	Inherited from CCMConstantsMixin
gd (FCpt)	EpicsSignal	{_constants_prefix}:GD	Distance between the rotation axis and the center of the sapphire sphere located on the Alio stage in mm.	config	Inherited from CCMConstantsMixin
lightpath_summary	SummarySignal			omitted	Inherited from LightpathMixin
energy	CCMEnergy		PseudoPositioner that moves the alio in terms of the calculated CCM energy.	hinted
energy_with_vernier	CCMEnergyWithVernier		PseudoPositioner that moves the alio in terms of the calculated CCM energy while also requesting a vernier move.	normal
energy_with_acr_status (FCpt)	CCMEnergyWithACRStatus	{prefix}	PseudoPositioner that moves the alio in terms of the calculated CCM energy while also requesting an energy change to ACR. This will wait on ACR to complete the move.	normal
alio (UnrelatedComponent)	CCMAlio		The motor that rotates the CCM crystal.	normal
theta2fine (UnrelatedComponent)	CCMMotor		The motor that controls the fine adjustment of the of the second crystal theta angle.	normal
theta2coarse (UnrelatedComponent)	CCMPico		The motor that controls the coarse adjustment of the of the second crystal theta angle.	normal
chi2 (UnrelatedComponent)	CCMPico		The motor that controls the adjustment of thesecond crystal chi angle.	normal
x (UnrelatedComponent)	CCMX		Combined motion of the CCM X motors.	normal
y (UnrelatedComponent)	CCMY		Combined motion of the CCM Y motors.	normal

Methods

calc_lightpath_state(x_up: float) → LightpathState

Update the fields used by the lightpath to determine in/out.

Compares the x position with the saved in and out values.

configure(d: Dict[str, Any]) → Tuple[Dict[str, Any], Dict[str, Any]]

Configure the device for something during a run

This default implementation allows the user to change any of the configuration_attrs. Subclasses might override this to perform additional input validation, cleanup, etc.

Parameters:

d (dict) – The configuration dictionary. To specify the order that the changes should be made, use an OrderedDict.

Returns:

• (old, new) tuple of dictionaries

• Where old and new are pre- and post-configure configuration states.

describe() → OrderedDictType[str, Dict[str, Any]]

Provide schema and meta-data for read().

This keys in the OrderedDict this method returns must match the keys in the OrderedDict return by read().

This provides schema related information, (ex shape, dtype), the source (ex PV name), and if available, units, limits, precision etc.

Returns:

data_keys (OrderedDict) – The keys must be strings and the values must be dict-like with the event_model.event_descriptor.data_key schema.

get(**kwargs)

Get the value of all components in the device

Keyword arguments are passed onto each signal.get(). Components beginning with an underscore will not be included.

get_lightpath_state(use_cache: bool = True) → LightpathState

Return the current LightpathState

Returns:

LightpathState – a dataclass containing the Lightpath state

insert(wait: bool = False) → MoveStatus

Move the x motors to the saved “in” position.

Parameters:

wait (bool, optional) – If True, wait for the move to complete. If False, return without waiting.

Returns:

move_status (MoveStatus) – A status object that tells you information about the success/failure/completion status of the move.

post_elog_status()

Post device status to the primary elog, if possible.

read() → OrderedDictType[str, Dict[str, Any]]

Read data from the device.

This method is expected to be as instantaneous as possible, with any substantial acquisition time taken care of in trigger().

The OrderedDict returned by this method must have identical keys (in the same order) as the OrderedDict returned by describe().

By convention, the first key in the return is the ‘primary’ key and maybe used by heuristics in bluesky.

The values in the ordered dictionary must be dict (-likes) with the keys {'value', 'timestamp'}. The 'value' may have any type, the timestamp must be a float UNIX epoch timestamp in UTC.

Returns:

data (OrderedDict) – The keys must be strings and the values must be dict-like with the keys {'value', 'timestamp'}

read_configuration() → OrderedDictType[str, Dict[str, Any]]

Dictionary mapping names to value dicts with keys: value, timestamp

To control which fields are included, change the Component kinds on the device, or modify the configuration_attrs list.

remove(wait: bool = False) → MoveStatus

Move the x motors to the saved “out” position.

Parameters:

wait (bool, optional) – If True, wait for the move to complete. If False, return without waiting.

Returns:

move_status (MoveStatus) – A status object that tells you information about the success/failure/completion status of the move.

reset_calc_constant_defaults(confirm: bool = True) → None

Put the default values into the ccm constants.

This can be useful if values were reset due to autosave errors or if they’ve otherwise accidentally been set to crazy values.

This relies on the default values in ccm.py being set up reasonably: theta0_deg = 15.1027 dspacing = 3.1356011499587773 gr = 3.175 gd = 231.303

Parameters:

confirm (bool, optional) – If True, we’ll ask for confirmation from the user before doing the reset. This is because an accidental reset can cost some time as we scramble to figure out what the values should be restored to.

screen()

Open a screen for controlling the device.

Default behavior is the typhos screen, but this method can be overridden for more specialized screens.

stage_group_instances() → Iterator[OphydObject]

Yields an iterator of subdevices that should be staged.

status() → str

Returns a str with the current pv values for the device.

stop(*, success=False)

Stop the Device and all (instantiated) subdevices

summary()

trigger() → StatusBase

Trigger the device and return status object.

This method is responsible for implementing ‘trigger’ or ‘acquire’ functionality of this device.

If there is an appreciable time between triggering the device and it being able to be read (via the read() method) then this method is also responsible for arranging that the StatusBase object returned by this method is notified when the device is ready to be read.

If there is no delay between triggering and being readable, then this method must return a StatusBase object which is already completed.

Returns:

status (StatusBase) – StatusBase object which will be marked as complete when the device is ready to be read.

warn_invalid_constants(only_new: bool = False) → None

Warn if we have invalid values for our calculation constants.

The motivation here is twofold: 1. It should be easy for the user to know what is wrong and

why. The calculations should not be opaque.

2. The user should still be able to do “something” if there is an issue here.

For values to be valid, the PVs need to be connected and all but theta0 must be nonzero. Theta0 should also not be zero, but it doesn’t break the math and someone could conceivably set it to zero during debug.

If this isn’t satisfied, we will show an appropriate warning message when this method is called. The intention is for this to pop up whenever we run the forward/inverse calculations.

For more detail, consider the following failure modes: 1. The constant PVs don’t connect and never connect

• In this case, we must warn that the constants IOC is off

• We should use the default values in calculations

2. The constant PVs connect, but their values are zero

• In this case, we must warn that the constant values were lost

• We should use the default values in calculations

3. The constant PVs connect, but disconnect later

• In this case, we should warn that the IOC died

• We should continue using the last known good values

Parameters:

only_new (bool, optional) – If False, the default, always show us the warnings. If True, do not show warnings if they have not changed.

Attributes

configuration_attrs

connected

dspacing_val

The dspacing value currently used in calculations.

This is the crystal lattice spacing.

This will be the value from the PV if things are working properly, otherwise it will fall back to the default value.

This is necessary because a value of 0 is nonphysical and in the case of a disconnected value the show must go on.

gd_val

The gd value currently used in calculations.

This is the distance between the rotation axis and the center of the sapphire sphere located on the Alio stage in mm.

This will be the value from the PV if things are working properly, otherwise it will fall back to the default value.

This is necessary because a value of 0 is nonphysical and in the case of a disconnected value the show must go on.

gr_val

The gr value currently used in calculations.

This is the radius of the sapphire ball connected to the Alio stage in mm.

This will be the value from the PV if things are working properly, otherwise it will fall back to the default value.

This is necessary because a value of 0 is nonphysical and in the case of a disconnected value the show must go on.

hints

kind

lightpath_cpts = ['x.up.user_readback']

md

needs_parent: list[type[OphydObject]] = [<class 'ophyd.signal.AttributeSignal'>, <class 'ophyd.signal.DerivedSignal'>, <class 'ophyd.areadetector.plugins.PluginBase'>, <class 'ophyd.pseudopos.PseudoSingle'>, <class 'pcdsdevices.signal.PVStateSignal'>, <class 'pcdsdevices.signal.AggregateSignal'>]

stage_group: list[Component] = None

subscriptions: ClassVar[FrozenSet[str]] = frozenset({'acq_done'})

theta0_deg_val

The theta0 value currently used in calculations.

This is the reference angle for the first crystal in deg.

This will be the value from the PV if things are working properly, otherwise it will fall back to the default value.

theta0_rad_val

The theta0 value currently used in calculations.

This is the reference angle for the first crystal in rad.

This will be the value from the PV if things are working properly, otherwise it will fall back to the default value.