pcdsdevices.valve.VRCDA

class pcdsdevices.valve.VRCDA(*args, input_branches=[], output_branches=[], **kwargs)

VRCDA = Valve with Readback and Control, Dual Acting

This is a valve that has no default state. It will maintain its current state until asked to change it, and it can be interlocked in either direction to prevent opening and to prevent closing.

This corresponds to ST_VRC_NO in the lcls-twincat-vacuum library, just like VRCNO, but it uses more of the PVs that were defined in ST_ValveBase.

Ophyd Device Components
Attribute	Class	Suffix	Docs	Kind	Notes
lightpath_summary	`SummarySignal`			omitted	Inherited from `VRC`
close_command	`EpicsSignalWithRBV`	`:CLS_SW`	Epics command to close valve	normal	Inherited from `VRCNO`
override_force_close	`EpicsSignalWithRBV`	`:FORCE_CLS`	Epics Command for close the valve in override mode	omitted	Inherited from `VRCNO`
override_on	`EpicsSignalWithRBV`	`:OVRD_ON`	Epics Command to set/reset Override mode	omitted	Inherited from `VRCNO`
close_ok	`EpicsSignalRO`	`:CLS_OK_RBV`	used for normally open valves	normal	Inherited from `VRCNO`
close_do	`EpicsSignalRO`	`:CLS_DO_RBV`	PLC Output to close valve	normal	Inherited from `VRCNO`
state	`EpicsSignalRO`	`:STATE_RBV`	Valve state	normal	Inherited from `VRC`
error_reset	`EpicsSignalWithRBV`	`:ALM_RST`	Reset Error state to valid by toggling this	normal	Inherited from `VRC`
open_limit	`EpicsSignalRO`	`:OPN_DI_RBV`	Open limit switch digital input	hinted	Inherited from `VRC`
closed_limit	`EpicsSignalRO`	`:CLS_DI_RBV`	Closed limit switch digital input	hinted	Inherited from `VRC`
valve_position	`EpicsSignalRO`	`:POS_STATE_RBV`	Ex: OPEN, CLOSED, MOVING, INVALID, OPEN_F	hinted	Inherited from `VRC`
open_command	`EpicsSignalWithRBV`	`:OPN_SW`	Epics command to Open valve	normal	Inherited from `VRC`
interlock_ok	`EpicsSignalRO`	`:OPN_OK_RBV`	Valve is OK to Open interlock	normal	Inherited from `VRC`
open_do	`EpicsSignalRO`	`:OPN_DO_RBV`	PLC Output to Open valve, 1 means 24V on command cable	normal	Inherited from `VRC`
override_status	`EpicsSignalRO`	`:OVRD_ON_RBV`	Epics Readback on Override mode	omitted	Inherited from `VRC`
override_force_open	`EpicsSignalWithRBV`	`:FORCE_OPN`	Epics Command to force open the valve inoverride mode	omitted	Inherited from `VRC`

Methods

calc_lightpath_state(open_limit: int, closed_limit: int) → LightpathState: Callback for updating inserted/removed for lightpath.

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

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

close_override: Fixes potential API breaks with old name

configuration_attrs

connected

connection_timeout

hints

kind

lightpath_cpts = ['open_limit', 'closed_limit']

md

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