pcdsdevices.epics_motor.EpicsMotorInterface

class pcdsdevices.epics_motor.EpicsMotorInterface(*args, **kwargs)

The standard EpicsMotor class, but with our interface attached.

This includes some PCDS preferences, but not any IOC differences.

Notes

The full list of preferences implemented here are:

Use the FltMvInterface mixin class for some name aliases and bells-and-whistles level functions.

Instead of using the limit fields on the setpoint PV, the EPICS motor class has the ‘LLM’ and ‘HLM’ soft limit fields for convenient usage. Unfortunately, pyepics does not update its internal cache of the limits after the first get attempt. We therefore disregard the internal limits of the PV and use the soft limit records exclusively.

The disable puts field ‘.DISP’ is added, along with enable() and disable() convenience methods. When ‘.DISP’ is 1, puts to the motor record will be ignored, effectively disabling the interface.

The description field keeps track of the motors scientific use along the beamline.

The post-move error logs only appear after a move in that session, not after a move in another user’s session. This is achieved by keeping track of whether or not a move was caused by this session and filtering self.log appropriately.

Ophyd Device Components
Attribute	Class	Suffix	Docs	Kind	Notes
user_readback (UpdateComponent)	`EpicsSignalROEditMD`	`.RBV`	Component attribute Component(EpicsSignalRO, '.RBV', auto_monitor=True, kind='hinted')	hinted	Inherited from `EpicsMotor`
user_setpoint (UpdateComponent)	`EpicsSignalEditMD`	`.VAL`	Component attribute Component(EpicsSignal, '.VAL', limits=True, auto_monitor=True, kind='normal')	normal	Inherited from `EpicsMotor`
user_offset	`EpicsSignal`	`.OFF`		config	Inherited from `EpicsMotor`
user_offset_dir	`EpicsSignal`	`.DIR`		config	Inherited from `EpicsMotor`
offset_freeze_switch	`EpicsSignal`	`.FOFF`		omitted	Inherited from `EpicsMotor`
set_use_switch	`EpicsSignal`	`.SET`		omitted	Inherited from `EpicsMotor`
velocity	`EpicsSignal`	`.VELO`		config	Inherited from `EpicsMotor`
acceleration	`EpicsSignal`	`.ACCL`		config	Inherited from `EpicsMotor`
motor_egu	`EpicsSignal`	`.EGU`		config	Inherited from `EpicsMotor`
motor_is_moving	`EpicsSignalRO`	`.MOVN`		normal	Inherited from `EpicsMotor`
motor_done_move	`EpicsSignalRO`	`.DMOV`		omitted	Inherited from `EpicsMotor`
high_limit_switch	`EpicsSignalRO`	`.HLS`		normal	Inherited from `EpicsMotor`
low_limit_switch	`EpicsSignalRO`	`.LLS`		normal	Inherited from `EpicsMotor`
high_limit_travel (UpdateComponent)	`EpicsSignal`	`.HLM`	Component attribute Component(EpicsSignal, '.HLM', auto_monitor=True, kind='omitted')	config	Inherited from `EpicsMotor`
low_limit_travel (UpdateComponent)	`EpicsSignal`	`.LLM`	Component attribute Component(EpicsSignal, '.LLM', auto_monitor=True, kind='omitted')	config	Inherited from `EpicsMotor`
direction_of_travel	`EpicsSignal`	`.TDIR`		normal	Inherited from `EpicsMotor`
motor_stop	`EpicsSignal`	`.STOP`		normal	Inherited from `EpicsMotor`
home_forward	`EpicsSignal`	`.HOMF`		normal	Inherited from `EpicsMotor`
home_reverse	`EpicsSignal`	`.HOMR`		normal	Inherited from `EpicsMotor`
disabled	`EpicsSignal`	`.DISP`		omitted
description	`EpicsSignal`	`.DESC`		normal
dial_position	`EpicsSignalRO`	`.DRBV`		normal
velocity_base	`EpicsSignal`	`.VBAS`		omitted
velocity_max	`EpicsSignal`	`.VMAX`		config
msta_raw	`EpicsSignalRO`	`.MSTA`		omitted

Methods

camonitor()

Shows a live-updating motor position in the terminal.

This will be the value that is returned by the position attribute.

This method ends cleanly at a ctrl+c or after a call to end_monitor_thread(), which may be useful when this is called in a background thread.

check_limit_switches()

Check the limits switches.

Returns:: limit_switch_indicator (str) – Indicate which limit switch is activated.

clear_limits(): Set both low and high limits to 0.

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.

disable()

Disables the motor.

When disabled, all EPICS puts to the base record will be dropped.

enable()

Enables the motor.

When disabled, all EPICS puts to the base record will be dropped.

end_monitor_thread(): Stop a camonitor() or wm_update() that is running in another thread.

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_high_limit(): Get high limit.

get_lim(flag)

Returns the travel limit of motor

flag > 0: returns high limit
flag < 0: returns low limit
flag == 0: returns None

Included here for compatibility with similar with SPEC command.

Parameters:

high (float) – Limit of travel in the positive direction.
low (float) – Limit of travel in the negative direction.

get_low_limit(): Get the low limit.

home(direction, wait=True, **kwargs)

Perform the default homing function in the desired direction

Parameters:: direction (HomeEnum) – Direction in which to perform the home search.

move(position: float, wait: bool = True, **kwargs) → MoveStatus

Move to a specified position, optionally waiting for motion to complete.

Parameters:

position – Position to move to
moved_cb (callable) – Call this callback when movement has finished. This callback must accept one keyword argument: ‘obj’ which will be set to this positioner instance.
timeout (float, optional) – Maximum time to wait for the motion. If None, the default timeout for this positioner is used.

Returns:

status (MoveStatus)

Raises:

TimeoutError – When motion takes longer than timeout
ValueError – On invalid positions
RuntimeError – If motion fails other than timing out

mv(position, timeout=None, wait=False, log=True)

Absolute move to a position.

Parameters:

position – Desired end position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
wait (bool, optional) – If True, wait for motion completion before returning. Defaults to False.
log (bool, optional) – If True, logs the move at INFO level.

mv_ginput(timeout=None)

Moves to a location the user clicks on.

If there are existing plots, this will be the position on the most recently active plot. If there are no existing plots, an empty plot will be created with the motor’s limits as the range.

mvr(delta, timeout=None, wait=False, log=True)

Relative move from this position.

Parameters:

delta (float) – Desired change in position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
wait (bool, optional) – If True, wait for motion completion before returning. Defaults to False.
log (bool, optional) – If True, logs the move at INFO level.

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.

screen()

Open a screen for controlling the device.

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

set(new_position: Any, *, timeout: float | None = None, moved_cb: Callable | None = None, wait: bool = False) → StatusBase

Set a value and return a Status object

Parameters:

new_position (object) – The input here is whatever the device requires (this should be over-ridden by the implementation. For example a motor would take a float, a shutter the strings {‘Open’, ‘Close’}, and a goineometer (h, k, l) tuples
timeout (float, optional) – Maximum time to wait for the motion. If None, the default timeout for this positioner is used.
moved_cb (callable, optional) –
Deprecated

Call this callback when movement has finished. This callback must accept one keyword argument: ‘obj’ which will be set to this positioner instance.
wait (bool, optional) –
Deprecated

If the method should block until the Status object reports it is done.

Defaults to False

Returns:

status (StatusBase) – Status object to indicate when the motion / set is done.

set_current_position(pos)

Configure the motor user position to the given value

Override ophyd’s method temporarily for error handling.

Parameters:: pos (number) – Position to set.

set_high_limit(value)

Limit of travel in the positive direction.

Parameters:: value (float) – High limit value to be set.
Raises:: ValueError – When motor in motion or position outside of limit.

set_lim(low, high)

Sets the low and high travel limits of motor

No action taken if motor is moving.
Low limit is set to lesser of (low, high)
High limit is set to greater of (low, high)

Included here for compatibility with similar with SPEC command.

Parameters:

high (float) – Limit of travel in the positive direction.
low (float) – Limit of travel in the negative direction.

set_low_limit(value)

Set the low limit.

Parameters:: value (float) – Limit of travel in the negative direction.
Raises:: ValueError – When motor in motion or position outside of limit.

set_position(position)

Alias for set_current_position.

Will fail if the motor does not have set_current_position.

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.

tweak(scale=0.1)

Control this motor using the arrow keys.

Use left arrow to step negative and right arrow to step positive. Use up arrow to increase step size and down arrow to decrease step size. Press q or ctrl+c to quit.

Parameters:: scale (float) – starting step size, default = 0.1

umv(position, timeout=None, log=True, newline=True)

Move to a position, wait, and update with a progress bar.

Parameters:

position (float) – Desired end position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
log (bool, optional) – If True, logs the move at INFO level.
newline (bool, optional) – If True, inserts a newline after the updates.

umvr(delta, timeout=None, log=True, newline=True)

Relative move from this position, wait, and update with a progress bar.

Parameters:

delta (float) – Desired change in position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
log (bool, optional) – If True, logs the move at INFO level.
newline (bool, optional) – If True, inserts a newline after the updates.

wait(timeout=None)

wm(): Get the mover’s current positon (where motor).

wm_update()

Shows a live-updating motor position in the terminal.

This will be the value that is returned by the position attribute.

This method ends cleanly at a ctrl+c or after a call to end_monitor_thread(), which may be useful when this is called in a background thread.

Attributes

configuration_attrs

connected

egu

Engineering units str if available, otherwise ‘’

Use the monitored/cached value rather than checking EPICS.

high_limit

hints

homed: Get the home status of the motor as reported by the MSTA field.

kind

limits: Override the limits attribute

low_limit

moving

Whether or not the motor is moving

Returns:: moving (bool)

msta: Returns the msta fields as a dictionary.

position

The current position of the motor in its engineering units

Returns:: position (float)

precision: The precision of the readback PV, as reported by EPICS

settle_time: Amount of time to wait after moves to report status completion

subscriptions: ClassVar[FrozenSet[str]] = frozenset({'_req_done', 'acq_done', 'done_moving', 'readback', 'start_moving'})

timeout: Amount of time to wait before to considering a motion as failed

tolerated_alarm = 0