Ready-to-Use Devices¶

These devices are have ready-made classes in Python. To configure them, the user need only provide a PV prefix and a name.

EpicsMotor¶

Create an EpicsMotor to communicate with a single EPICS motor record:

from ophyd import EpicsMotor

# the two-theta motor
tth = EpicsMotor('XF:28IDC-ES:1{Dif:1-Ax:2ThI}Mtr', name='tth')

class ophyd.epics_motor.EpicsMotor(prefix='', *, name, kind=None, read_attrs=None, configuration_attrs=None, parent=None, **kwargs)¶

An EPICS motor record, wrapped in a Positioner

Keyword arguments are passed through to the base class, Positioner

Parameters:

prefix : str: The record to use
read_attrs : sequence of attribute names: The signals to be read during data acquisition (i.e., in read() and describe() calls)
name : str, optional: The name of the device
parent : instance or None: The instance of the parent device, if applicable
settle_time : float, optional: The amount of time to wait after moves to report status completion
timeout : float, optional: The default timeout to use for motion requests, in seconds.

check_value(pos)¶: Check that the position is within the soft limits

egu¶: The engineering units (EGU) for a position

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.

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, wait=True, **kwargs)¶

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

moving¶

Whether or not the motor is moving

Returns:	moving : bool

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

set_current_position(pos)¶

Configure the motor user position to the given value

Parameters:	pos Position to set.

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.

EpicsScaler¶

Create an EpicsScaler to control an EPICS scaler record:

from ophyd import EpicsScaler
scaler = EpicsScaler('XF:28IDC-ES:1{Sclr:1}', name='tth')

class ophyd.scaler.EpicsScaler(*args, **kwargs)¶: SynApps Scaler Record interface

EpicsMCA and EpicsDXP¶

MCA records and DXP-based devices are also supported, through the EpicsMCA and EpicsDXP devices.

class ophyd.mca.EpicsMCARecord(*args, **kwargs)¶: SynApps MCA Record interface

class ophyd.mca.EpicsDXP(prefix='', *, name, kind=None, read_attrs=None, configuration_attrs=None, parent=None, **kwargs)¶: All high-level DXP parameters for each channel

MotorBundle¶

Creating ‘bundles’ of motors is very common so we also have a helper class that tweaks the default behavior of read_attrs, configuration_attrs, and hints

class ophyd.epics_motor.MotorBundle(prefix='', *, name, kind=None, read_attrs=None, configuration_attrs=None, parent=None, **kwargs)¶

Sub-class this to device a bundle of motors

This provides better default behavior for :ref:hints.

This must be sub-classed (like Device) to be useful.

from ophyd import MotorBundle, EpicsMotor
from ophyd import Component as Cpt

class StageXY(MotorBundle):
    x = Cpt(EpicsMotor, ':X')
    y = Cpt(EpicsMotor, ':Y')

stage = StageXY('STAGE_PV', name='stage')