pcdsdevices.twincat_motor.TwinCATAxis

class pcdsdevices.twincat_motor.TwinCATAxis(prefix='', *, name, kind=None, read_attrs=None, configuration_attrs=None, parent=None, **kwargs)

TwinCAT NC AXIS_REF motor device with error handling and homing.

This class extends the TwinCATMotorInterface with:

Additional components (PLC diagnostics, homing command and mode).

end-of-move and error handling: move completion status is checked against PLC error and status codes, so that motion failures are accurately detected and reported.

A clear_error method to reset PLC motion errors from Python or GUI.

A home() method exposing all PLC-configured homing routines with proper mode setting, actuation, status, and timing.

Robust session-tracking and logging logic for post-move diagnostics.

Note

Some methods in this class are identical or adapted from BeckhoffAxis, to ensure the error-handling, staging, homing, and value checking logic behaves identically.

actuate_homePytmcSignal: PV to trigger a homing command.
home_modePytmcSignal: PV to select the homing mode (see HomeEnum).
plcBeckhoffAxisPLC: Sub-device interface for further PLC status and diagnostics.

prefixstr: The EPICS PV prefix for this motor.
namestr: An identifying name for this motor.
settle_timefloat, optional: The amount of extra time to wait before interpreting a move as done.
timeoutfloat, optional: The amount of time to wait before automatically marking a long in-progress move as failed.

Ophyd Device Components
Attribute	Class	Suffix	Docs	Kind	Notes
setpoint	`PytmcSignal`	`fPosition`		hinted	Inherited from `TwinCATMotorInterface`
readback	`PytmcSignal`	`fActPosition`		hinted	Inherited from `TwinCATMotorInterface`
done	`PytmcSignal`	`bDone`		normal	Inherited from `TwinCATMotorInterface`
actuate	`PytmcSignal`	`bMoveCmd`		normal	Inherited from `TwinCATMotorInterface`
stop_signal	`PytmcSignal`	`bHalt`		normal	Inherited from `TwinCATMotorInterface`
reset_signal	`PytmcSignal`	`bReset`		normal	Inherited from `TwinCATMotorInterface`
velocity	`PytmcSignal`	`fVelocity`		config	Inherited from `TwinCATMotorInterface`
acceleration	`PytmcSignal`	`fAcceleration`		config	Inherited from `TwinCATMotorInterface`
deceleration	`PytmcSignal`	`fDeceleration`		config	Inherited from `TwinCATMotorInterface`
jerk	`PytmcSignal`	`fJerk`		config	Inherited from `TwinCATMotorInterface`
enable_mode	`PytmcSignal`	`eEnableMode`		config	Inherited from `TwinCATMotorInterface`
brake_mode	`PytmcSignal`	`eBrakeMode`		config	Inherited from `TwinCATMotorInterface`
motor_is_moving	`PytmcSignal`	`bMoving`		normal	Inherited from `TwinCATMotorInterface`
motor_is_moving_negative	`PytmcSignal`	`bNegativeDirection`		normal	Inherited from `TwinCATMotorInterface`
motor_is_moving_positive	`PytmcSignal`	`bPositiveDirection`		normal	Inherited from `TwinCATMotorInterface`
power_is_enabled	`PytmcSignal`	`bPowerIsEnabled`		normal	Inherited from `TwinCATMotorInterface`
high_limit_switch	`PytmcSignal`	`bLimitFwd`		normal	Inherited from `TwinCATMotorInterface`
low_limit_switch	`PytmcSignal`	`bLimitBwd`		normal	Inherited from `TwinCATMotorInterface`
negative_dir_enabled	`PytmcSignal`	`bNegativeMotionIsEnabled`		normal	Inherited from `TwinCATMotorInterface`
positive_dir_enabled	`PytmcSignal`	`bPositiveMotionIsEnabled`		normal	Inherited from `TwinCATMotorInterface`
command	`PytmcSignal`	`eCommand`		normal	Inherited from `TwinCATMotorInterface`
motor_egu	`PytmcSignal`	`sEGU`		normal	Inherited from `TwinCATMotorInterface`
low_limit_travel	`EpicsSignal`	`NC:MinPos:Val_RBV`		config	Inherited from `TwinCATMotorInterface`
high_limit_travel	`EpicsSignal`	`NC:MaxPos:Val_RBV`		config	Inherited from `TwinCATMotorInterface`
low_limit_enable	`EpicsSignal`	`NC:SoftPosMinOn:Val_RBV`		config	Inherited from `TwinCATMotorInterface`
high_limit_enable	`EpicsSignal`	`NC:SoftPosMaxOn:Val_RBV`		config	Inherited from `TwinCATMotorInterface`
homed	`PytmcSignal`	`bHomed`		normal
home_mode	`PytmcSignal`	`eHomeMode`		config
plc	`BeckhoffAxisPLC`		PLC error handling and aux functions.	normal

Methods

camonitor()

Shows a live-updating motor position in the terminal.

This will be the value that is returned by the position attribute.

This method ends cleanly at a ctrl+c or after a call to end_monitor_thread(), which may be useful when this is called in a background thread.

check_limit_switches()

Check the limit switches.

Logic structure reused from EpicsMotorInterface for API consistency. Returns a string summary.

clear_error(): Identical to BeckhoffAxis.clear_error. Clears any active motion/plc errors on this axis.

clear_limits()

Set both low and high limits to 0.

Duplicated from EpicsMotorInterface for function and API consistency.

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.

end_monitor_thread(): Stop a camonitor() or wm_update() that is running in another thread.

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.

home(wait: bool = True, **kwargs)

Adapted from BeckhoffAxis.home.

Executes the PLC-programmed home routine. For hardware where only one homing method may be active/configured.

move(position: float, wait: bool = True, **kwargs) → MoveStatus

Functionally adapted from BeckhoffAxis.move.

Sets up tailored end-of-move handler and error capture, as in BeckhoffAxis. Prepares a new MoveStatus for custom error interpretation.

mv(position, timeout=None, wait=False, log=True)

Absolute move to a position.

Parameters:

position – Desired end position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
wait (bool, optional) – If True, wait for motion completion before returning. Defaults to False.
log (bool, optional) – If True, logs the move at INFO level.

mv_ginput(timeout=None)

Moves to a location the user clicks on.

If there are existing plots, this will be the position on the most recently active plot. If there are no existing plots, an empty plot will be created with the motor’s limits as the range.

mvr(delta, timeout=None, wait=False, log=True)

Relative move from this position.

Parameters:

delta (float) – Desired change in position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
wait (bool, optional) – If True, wait for motion completion before returning. Defaults to False.
log (bool, optional) – If True, logs the move at INFO level.

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.

reset(*, success=False)

screen()

Open a screen for controlling the device.

Default behavior is the typhos screen, but this method can be overridden for more specialized screens.

set(new_position: Any, *, timeout: float = None, moved_cb: Callable = None, wait: bool = False) → StatusBase

Set a value and return a Status object

Parameters:

new_position (object) – The input here is whatever the device requires (this should be over-ridden by the implementation. For example a motor would take a float, a shutter the strings {‘Open’, ‘Close’}, and a goineometer (h, k, l) tuples
timeout (float, optional) – Maximum time to wait for the motion. If None, the default timeout for this positioner is used.
moved_cb (callable, optional) –
Deprecated

Call this callback when movement has finished. This callback must accept one keyword argument: ‘obj’ which will be set to this positioner instance.
wait (bool, optional) –
Deprecated

If the method should block until the Status object reports it is done.

Defaults to False

Returns:

status (StatusBase) – Status object to indicate when the motion / set is done.

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.

set_high_limit(value)

Limit of travel in the positive direction. Adapted from EpicsMotorInterface.

Parameters:: value (float) – High limit value to be set.
Raises:: ValueError – When in motion or position outside of limit.

set_low_limit(value)

Set the low limit. Adapted from EpicsMotorInterface.

Parameters:: value (float) – Limit of travel in the negative direction.
Raises:: ValueError – When in motion or position outside of limit.

set_position(position)

Alias for set_current_position.

Will fail if the motor does not have set_current_position.

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.

tweak(scale=0.1)

Control this motor using the arrow keys.

Use left arrow to step negative and right arrow to step positive. Use up arrow to increase step size and down arrow to decrease step size. Press q or ctrl+c to quit.

Parameters:: scale (float) – starting step size, default = 0.1

umv(position, timeout=None, log=True, newline=True)

Move to a position, wait, and update with a progress bar.

Parameters:

position (float) – Desired end position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
log (bool, optional) – If True, logs the move at INFO level.
newline (bool, optional) – If True, inserts a newline after the updates.

umvr(delta, timeout=None, log=True, newline=True)

Relative move from this position, wait, and update with a progress bar.

Parameters:

delta (float) – Desired change in position.
timeout (float, optional) – If provided, the mover will throw an error if motion takes longer than timeout to complete. If omitted, the mover’s default timeout will be use.
log (bool, optional) – If True, logs the move at INFO level.
newline (bool, optional) – If True, inserts a newline after the updates.

wait(timeout=None)

wm(): Get the mover’s current positon (where motor).

wm_update()

Shows a live-updating motor position in the terminal.

This will be the value that is returned by the position attribute.

This method ends cleanly at a ctrl+c or after a call to end_monitor_thread(), which may be useful when this is called in a background thread.

Attributes

actuate_value = 1

configuration_attrs

connected

connection_timeout

done_value = 1

egu: The engineering units (EGU) for this motor. Updated via the motor_egu PV.

enabled

returns: * bool – True if power is enabled and either negative or positive direction is enabled. * Explanation * ———– * - Returns True if –

Power is on (power_is_enabled)

At least one direction (negative_dir_enabled OR positive_dir_enabled) is enabled

high_limit

hints

kind

limits

Override limits property to always return the latest values from the soft limit PVs (low_limit_travel and high_limit_travel).

This ensures no stale/cached values are reported.

low_limit

moving

Whether or not the motor is moving.

Duplicated logic from EpicsMotorInterface for API consistency.

Returns:: moving (bool)

position

The current position of the motor in its engineering units

Returns:: position (float)

put_complete

settle_time: Amount of time to wait after moves to report status completion

stop_value = 1

subscriptions: ClassVar[FrozenSet[str]] = frozenset({'_req_done', 'acq_done', 'done_moving', 'readback', 'start_moving'})

timeout: Amount of time to wait before to considering a motion as failed

tolerated_alarm = 0