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

prefixstr

The record to use

read_attrssequence of attribute names

The signals to be read during data acquisition (i.e., in read() and describe() calls)

namestr, optional

The name of the device

parentinstance or None

The instance of the parent device, if applicable

settle_timefloat, optional

The amount of time to wait after moves to report status completion

timeoutfloat, optional

The default timeout to use for motion requests, in seconds.

check_value(pos)

Check that the position is within the soft limits

property 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

highfloat

Limit of travel in the positive direction.

lowfloat

Limit of travel in the negative direction.

home(direction, wait=True, **kwargs)

Perform the default homing function in the desired direction

Parameters

directionHomeEnum

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_cbcallable

Call this callback when movement has finished. This callback must accept one keyword argument: ‘obj’ which will be set to this positioner instance.

timeoutfloat, optional

Maximum time to wait for the motion. If None, the default timeout for this positioner is used.

Returns

statusMoveStatus

Raises

TimeoutError

When motion takes longer than timeout

ValueError

On invalid positions

RuntimeError

If motion fails other than timing out

property moving

Whether or not the motor is moving

Returns

movingbool

property position

The current position of the motor in its engineering units

Returns

positionfloat

property precision

The precision of the readback PV, as reported by EPICS

property report

A report on the object.

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

highfloat

Limit of travel in the positive direction.

lowfloat

Limit of travel in the negative direction.

stop(*, success=False)

Stop the Device and all (instantiated) subdevices

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

stop(*, success=False)

Stop the Device and all (instantiated) subdevices

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')