pylinkam

This Python module provides Python bindings for the official C/C++ Linkam SDK. It enables monitoring and control of various instruments provided by Linkam Scientific. The library can optionally be used with the pint package to handle unit conversion.

Background

We use a Linkam HFS600E-PB4 stage with T96 controller for gas sensing experiments in the Swinburne Sensor Technology Lab. This library has been parted out from our custom developed experiment software for general use. If you find the package useful we'd love to hear about your projects!

Installation

Note that the Linkam SDK binary files (LinkamSDK.dll or libLinkamSDK.so) and the required license file (typically Linkam.lsk) are not distributed as part of this module.

By default, the module will look for the Linkam SDK binary using the $PATH environment variable via the ctypes module and will automatically append the module directory before searching.

1. Place LinkamSDK.dll (debug or release) and Linkam.lsk files inside the pylinkam module folder (the one that contains __init__.py). Alternately, at runtime you can specify a binary name (remove the .dll extension on Windows) and path to access these files.
2. Run demo.py to check for any connection/path issues. This will set the stage temperature to 25°C temporarily.

Getting Module Path and Troubleshooting

Running the following in a Python console/environment should tell you where the place the LinkamSDK.dll (or Linux equivilent) and Linkam.lsk files.

import pylinkam
print(pylinkam.__file__)

The SDK also generates log files in this directory by default, this is the first place to check when diagnosing issues. If you see license errors (quite common even in legimate installations) you'll need to contact your equipment supplier or Linkam support.

Usage

Context Manager Example

Initialise the SDK by creating an instance of pylinkam.sdk.SDKWrapper providing optional paths for SDK binary files and the license file. Once initialised, use the connect() method to create a context manager for the connection to a device.

from pylinkam import interface, sdk


with sdk.SDKWrapper() as wrapper:
    with wrapper.connect() as connection:
        print(f"Name: {connection.get_controller_name()}")

        temperature = connection.get_value(interface.StageValueType.HEATER1_TEMP)
        connection.set_value(interface.StageValueType.HEATER_SETPOINT, 30)

Manual Example

You can also use the classes directly without context managers, but you'll have to close connections manually to avoid memory leaks.

from pylinkam import interface, sdk


connection = sdk.SDKWrapper().connect_usb()

print(f"Name: {connection.get_controller_name()}")

temperature = connection.get_value(interface.StageValueType.HEATER1_TEMP)
connection.set_value(interface.StageValueType.HEATER_SETPOINT, 30)

connection.close()

Python Versions

This library requires a minimum of Python 3.6 to function. Newer versions should be compatible.

CPU Architecture

This library has only been tested on 64-bit x86 processors.

Tested Devices

This library has been developed for the following Linkam instruments/addons, a check indicates that functionality has been verified on working hardware:

• T96 System Controller (via USB)
• T96 System Controller (via RS-232, might work 🤷)
• HFS600E-PB4 Probe Stage (all stages should be supported)
• RH95 Humidity Controller
• LNP96 Cooling Option (should work)

Note that connecting multiple devices to a single host is untested, though the connect functions per the Linkam API can accept a serial number.

Tested API Versions and Platforms

• v3.0.5.5 on Windows 10
• v3.0.15.35 on Windows 10
• v3.0.19.12 on Windows 10

In theory the SDK binary files for Linux should have identical mappings, but this hasn't been tested. Versions < 1.2.3 used WinDLL to load the Linkam SDK binary, however more recent versions will automatically detect the platform and use CDLL when not on Windows. We don't have hardware connected to a Linux machine to test, so please report any issues.

Acknowledgments

Developed at Swinburne University of Technology. If used in an academic or research project, please consider citing this work as it helps attract funding and track research outputs:

C. J. Harrison and M. Shafiei. pylinkam. (2022). [Online]. doi: https://doi.org/10.5281/zenodo.6758012

This activity received funding from ARENA as part of ARENA’s Research and Development Program – Renewable Hydrogen for Export (Contract No. 2018/RND012). The views expressed herein are not necessarily the views of the Australian Government, and the Australian Government does not accept responsibility for any information or advice contained herein.

Disclaimer

This library is not an official product or service of Linkam Scientific Instruments Ltd. This library is not endorsed, sponsored, or supported by Linkam Scientific Instruments Ltd. The name Linkam as well as related names, marks, emblems, and images are registered trademarks of their respective owners.