pcdsdevices.mps.MPS

class pcdsdevices.mps.MPS(*args, veto=False, **kwargs)

Class to interpret a single bit of MPS information.

There are three major attributes of each MPS bit that are relevant to operations; faulted , bypassed and veto_capable. The first is the most obvious: when the device is faulted, it reports as such to the MPS system. However, how this is actually interpreted by the MPS is determined by whether the bit is bypassed, and if there is a veto device upstream such that the fault can be safely ignored. The summary of both the bypass and fault signals is contained within tripped. The bypassed state is reported through EPICS as well but unfortunately whether a device is considered capable of “veto-ing” or is vetoed by another device is not broadcast by EPICS so this is held within this device and the lightpath module.

Parameters:

• prefix (str) – PV prefix of MPS information.

• name (str) – Name of MPS bit.

• veto (bool, optional) – Whether or not the the device is capable of vetoing downstream faults.

Ophyd Device Components

Attribute	Class	Suffix	Docs	Kind	Notes
fault	EpicsSignalRO	_MPSC		hinted
bypass	EpicsSignal	_BYPS		config

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.

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

SUB_FAULT_CH = 'sub_mps_faulted'

bypassed

Bypass state of the MPS bit.

configuration_attrs

connected

faulted

Whether the MPS bit is faulted or not.

hints

kind

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

tripped

Whether this will trip the MPS system.

This is based off of both the faulted state as well as any temporary bypasses on the MPS bit.