pcdsdevices.stopper.PPSStopper2PV

class pcdsdevices.stopper.PPSStopper2PV(prefix, *, in_suffix='INSUM', out_suffix='OUTSUM', in_value=1, out_value=1, **kwargs)

PPS Stopper with two PVs defining the state together.

One PV is the state of the IN limit switch, one is the state of the OUT limit switch.

By default, these stoppers have IN/NOT_IN and OUT/NOT_OUT PVs with a PV suffix of ‘INSUM’ and ‘OUTSUM’, but often this is not true and there are init arguments to get around these inconsistencies.

We have no direct control over these from the photon side, so this Device only serves as a way to check status and display in the lightpath.

In addition to standard device args, note the following additions:

Parameters:

• in_suffix (str, optional) – The suffix for the in_signal that tells us if the stopper is inserted or not. Defaults to ‘INSUM’.

• out_suffix (str, optional) – The suffix for the out_signal that tells us if the stopper is removed or not. Defaults to ‘OUTSUM’

• in_value (int, optional) – The value of the in_signal that tells us that the stopper is inserted. Defaults to 1.

• out_value (int, optional) – The value of the out_signal that tells us that the stopper is removed. Defaults to 1.

Ophyd Device Components

Attribute	Class	Suffix	Docs	Kind	Notes
lightpath_summary	SummarySignal			omitted	Inherited from LightpathMixin
in_signal (FCpt)	EpicsSignalRO	{prefix}{in_suffix}	Tells us if the stopper is IN or NOT_IN	hinted
out_signal (FCpt)	EpicsSignalRO	{prefix}{out_suffix}	Tells us if the stopper is OUT or NOT_OUT	hinted

Methods

calc_lightpath_state(in_signal: int, out_signal: int) → LightpathState

Create and return a LightpathState object containing information needed for lightpath, given a set of signal values

kwargs should be the same as the signal names provided in lightpath_cpts

Device logic goes here.

Returns:

LightpathState – a dataclass containing the Lightpath state

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

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.

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.

Attributes

configuration_attrs

connected

hints

kind

lightpath_cpts = ['in_signal', 'out_signal']

md

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