pcdsdevices.valve.ValveBase

class pcdsdevices.valve.ValveBase(prefix='', *, name, kind=None, read_attrs=None, configuration_attrs=None, parent=None, child_name_separator='_', connection_timeout=<object object>, **kwargs)

Base class for valves.

Valves are normally closed by default.

Newer class. This and below are still missing some functionality. Still need to work out replacement of old classes.

This corresponds to ST_ValveBase in the lcls-twincat-vacuum library. PVs that are omitted in VCGLegacy are instead put in the VVC class.

Ophyd Device Components

Attribute	Class	Suffix	Docs	Kind	Notes
valve_position	EpicsSignalRO	:POS_STATE_RBV	Ex: OPEN, CLOSED, MOVING, INVALID, OPEN_F	hinted
open_command	EpicsSignalWithRBV	:OPN_SW	Epics command to Open valve	normal
interlock_ok	EpicsSignalRO	:OPN_OK_RBV	Valve is OK to Open interlock	normal
open_do	EpicsSignalRO	:OPN_DO_RBV	PLC Output to Open valve, 1 means 24V on command cable	normal
error_reset	EpicsSignalWithRBV	:ALM_RST	Reset Error state to valid by toggling this	normal

Methods

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.

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.

classmethod set_defaults(*, connection_timeout=10.0)

Set class-wide defaults for device communications

This may be called only before any instances of Device are made.

This setting applies to the class it is called on and all its subclasses. For example,

>>> Device.set_defaults(...)

will apply to any Device subclass.

Parameters:

connection_timeout (float, optional) – Time (seconds) allocated for establishing a connection with the IOC.

Raises:

RuntimeError – If called after EpicsSignalBase has been instantiated for the first time.

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

connection_timeout

hints

kind

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