pcdsdevices.valve.VFS

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

VFS = Fast Shutter Valve

This valve is typically used to protect sensitive beamline components from bad vacuum events that would otherwise damage them. It has an especially fast response time compared to other vacuum system elements.

This corresponds with ST_VFS in the lcls-twincat-vacuum library, but rather than inherit from other classes it includes repeated elements from ST_ValveBase.

Ophyd Device Components

Attribute	Class	Suffix	Docs	Kind	Notes
lightpath_summary	SummarySignal			omitted	Inherited from LightpathMixin
valve_position	EpicsSignalRO	:POS_STATE_RBV	Ex: OPEN, CLOSED, MOVING, INVALID, OPEN_F	hinted
vfs_state	EpicsSignalRO	:STATE_RBV	Fast Shutter Current State	hinted
request_close	EpicsSignalWithRBV	:CLS_SW	Request Fast Shutter to Close. When both closeand open are requested, VFS will close.	normal
request_open	EpicsSignalWithRBV	:OPN_SW	Request Fast Shutter to Open. Requires a risingEPICS signal to open. When both close andopen are requested, VFS will close.	normal
reset_vacuum_fault	EpicsSignalWithRBV	:ALM_RST	Reset Fast Shutter Vacuum Faults: fastsensor triggered, fast sensor turned off.To open VFS, this needs to be reset to TRUEafter a vacuum event.	normal
override_mode	EpicsSignalWithRBV	:OVRD_ON	Epics Command to set Override mode	normal
override_force_open	EpicsSignalWithRBV	:FORCE_OPN	Epics Command to force openthe valve in override mode	normal
gfs_name	EpicsSignalRO	:GFS_RBV	Gauge Fast Sensor Name	normal
gfs_trigger	EpicsSignalRO	:TRIG_RBV	Gauge Fast Sensor Input Trigger	normal
position_close	EpicsSignalRO	:CLS_DI_RBV	Fast Shutter Closed Valve Position	normal
position_open	EpicsSignalRO	:OPN_DI_RBV	Fast Shutter Open Valve Position	normal
vac_fault_ok	EpicsSignalRO	:VAC_FAULT_OK_RBV	Fast Shutter Vacuum Fault OK Readback	normal
mps_ok	EpicsSignalRO	:MPS_FAULT_OK_RBV	Fast Shutter Fast Fault Output OK	normal
veto_device	EpicsSignalRO	:VETO_DEVICE_RBV	Name of device that can veto this VFS	normal

Methods

calc_lightpath_state(position_open: int, position_close: int)

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

configuration_attrs

connected

connection_timeout

hints

kind

lightpath_cpts = ['position_open', 'position_close']

md

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