pyThorlabsAPT 0.11

A python library/GUI to access and control motors via the APT protocol.

pyThorlabsAPT

pyThorlabsAPT is a Python library/GUI interface to control any motor compatible with the Thorlabs APT communication protocol. The package is composed of two parts, a low-level driver to perform basic operations, and a high-level GUI, written with PyQt5, which can be easily embedded into other GUIs. The low-level driver is essentially a wrapper of the excellent package thorlabs_apt, with a few tweaks to speed up loading time and error handling. Since thorlabs_apt is not available via pip, its code has been embedded in the code of this package, here.

Table of Contents

• Installation
• Usage via the low-level driver
  • Examples
• Usage as a stand-alone GUI interface
• Embed the GUI within another GUI

Installation

The package uses the Thorlabs APT.dll shared library, and therefore it only works under Windows. To install, follow these steps:

1. Install the script via the package manager pip,

pip install pyThorlabsAPT

2. Install the APT software from here. The version of the software (32 or 64 bit) must match the one of your python installation.

3. Locate the file APT.dll which has been installed on your computer by the APT software. This file will typically be in the folder "[APT Installation Folder]\APT Server", where [APT Installation Folder] is the installation folder of the APT software (typically [APT Installation Folder] = C:\Program Files\Thorlabs\APT). Copy the APT.dll into one of these locations:

   • C:\Windows\System32.
   • The folder of your python application.
   • Inside the "[Python packages folder]\pyThorlabsAPT horlabs_apt". Most of the times [Python packages folder] = "[Python folder]\Lib\site-packages".

These steps are enough to run the low-level driver of pyThorlabsAPT. In order to use the GUI, it is necessary to install additional libraries, specified in the requirements.txt file,

pip install abstract_instrument_interface>=0.6
pip install "PyQt5>=5.15.6"
pip install "pyqtgraph>=0.12.4"
pip install numpy

Usage via the low-level driver

pyThorlabsAPT can be used to control a device from the command line or from your Python script.

Example

from pyThorlabsAPT.driver import pyThorlabsAPT
instrument = pyThorlabsAPT()
available_devices = instrument.list_devices()
print(available_devices)
instrument.connect_device(device_addr = available_devices[0][0])
instrument.hardware_info
instrument.move_home()
instrument.move_by(10)
instrument.is_in_motion # returns True when instrument is moving
instrument.position = 10 # Goes to position 10

Most of the properties and methods of the class pyThorlabsAPT are actually inherited from the thorlabs_apt package. Here below the main properties and methods are summarized for quick reference.

Properties

Property	Type	Description	Can be set?	Notes
position	float	Read or set current position of the motor.	Yes
stage_info	(float,float,int,float)	Read current stage parameters	No

Methods

Method	Returns	Description
list_devices()	list	Returns a list of all available devices. Each element of the list identifies a different device, and it is a three-element list in the form [address,identity,model]. The string address contains the physical address of the device. The string idn contains the 'identity' of the device. The string model contains the device model.
connect_device(device_addr: str)	(str,int)	Attempt to connect to the device identified by the address in the string device_addr. It returns a list of two elements. The first element is a string containing either the address of the connected device or an error message. The second element is an integer, equal to 1 if connection was succesful or to 0 otherwise.
disconnect_device()	(str,int)	Attempt to disconnect the currently connected device. It returns a list of two elements. The first element is a string containing info on succesful disconnection or an error message. The second element is an integer, equal to 1 if disconnection was succesful or to 0 otherwise.
move_home()
move_by(movement: float)	int	Set the zero to the currently connected (if any) console. The returned value is 1 if the operation was successful, or 0 if any error occurred.
set_stage_axis_info(min:float, max:float, units:int, pitch:float)

Usage as a stand-alone GUI interface

The installation sets up an entry point for the GUI. Just typing

pyThorlabsAPT

in the command prompt will start the GUI.

Embed the GUI within another GUI

The GUI controller can also be easily integrated within a larger graphical interface, as shown in the [TO DO]