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(self, pos)

Check that the position is within the soft limits

egu

The engineering units (EGU) for a position

home(self, 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(self, 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(self, pos)

Configure the motor user position to the given value

Parameters:
pos

Position to set.

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')