class Z825BLinearStage(LinearStageBase):
"""
A linear motor.
Parameters
----------
pyroname : str
The name of the PyroLab object as registered with the nameserver.
ns_host : str, optional
The hostname of the PyroLab nameserver (default "localhost").
ns_port : int, optional
The port of the PyroLab nameserver (default "9090").
"""
def __init__(self,
pyroname: str = "",
ns_host: str = "localhost",
ns_port: int = 9090) -> None:
super().__init__(pyroname)
with locate_ns(host=ns_host, port=ns_port) as ns:
self.driver = Proxy(ns.lookup(pyroname))
self.driver.autoconnect()
self._step_size = None
@property
def step_size(self) -> float:
"""The jog step size in mm."""
return self._step_size
@step_size.setter
def step_size(self, step_size: float) -> None:
if step_size != self._step_size:
self.driver._pyroClaimOwnership()
self.driver.jog_step_size = step_size
self._step_size = step_size
def move_to(self, position: float) -> None:
"""
Moves to a new position.
This motor adjusts for backlash; a given position will always be
approached from the "negative" direction. That may require overshooting
the commanded position in order to always approach it again from a
consistent direction.
If stepping in short steps, it is therefore most efficient to step from
negative to positive values to avoid backlash adjustments on each step.
Parameters
----------
position : float
The new position to move to.
"""
self.driver._pyroClaimOwnership()
if self._requires_backlash_adjustment(position):
self.driver.move_to(position - (self.driver.backlash * 1.5))
self.driver.move_to(position)
def move_by(self, distance: float) -> None:
"""
Jogs the motor by a fixed distance.
Parameters
----------
distance : float
The distance to move the motor. A positive value will move the
motor forward, and a negative value will move the motor backwards.
"""
self.driver._pyroClaimOwnership()
if np.abs(distance) != self.step_size:
self.step_size = np.abs(distance)
if distance > 0:
self.driver.jog("forward")
else:
self.driver.jog("backward")
def move_cont(self, direction: str) -> None:
"""
Starts a continuous move in the specified direction.
Parameters
----------
direction : str
The direction to move the motor, either "forward" or "backward".
"""
self.driver._pyroClaimOwnership()
self.driver.move_continuous(direction)
def _requires_backlash_adjustment(self, position: float) -> bool:
"""
Determine if the new position command needs to compensate for backlash.
The ThorLabs linear stages have a small backlash distance. To ensure
as accurate a reposition as possible when moving to the same location
multiple times, the motor will always approach the position from the
same direction. This function determines whether that requires
overshooting the current position before reapproaching.
Parameters
----------
position : float
The position to move to.
Returns
-------
bool
Whether backlash compensation is required.
"""
if position < self.get_position():
return True
return False
def stop(self) -> None:
"""
Stop all motion.
"""
self.driver._pyroClaimOwnership()
self.driver.stop()
def get_position(self) -> float:
"""
Get the current position in millimeters.
"""
self.driver._pyroClaimOwnership()
return self.driver.get_position()
def home(self) -> None:
"""
Home the motor.
"""
self.driver._pyroClaimOwnership()
self.driver.go_home()
def status(self) -> int:
"""
Returns a nonzero value if the motor is busy.
"""
pass
# -*- coding: utf-8 -*-
#
# Copyright © PyroLab Project Contributors
# Licensed under the terms of the GNU GPLv3+ License
# (see pyrolab/__init__.py for details)
"""
Kinesis KCube Driver Example
============================
This example demonstrates the use of the Thorlabs KCube DC Servo controlling a
Z825B translational stage using PyroLab.
"""
from pyrolab.api import NameServerConfiguration, Proxy, locate_ns
nscfg = NameServerConfiguration(host="yourdomain.com")
nscfg.update_pyro_config()
# Be considerate; don't stay connected to the nameserver too long.
with locate_ns() as ns:
motor = Proxy(ns.lookup("Z825B_PyroName"))
motor.autoconnect()
print(motor.get_position())
motor.close()